Regulation No. 110-00

Name:Regulation No. 110-00
Description:Compressed Natural Gas (CNG) Vehicles.
Official Title:Uniform Provisions Concerning the Approval of: I. Specific Components of Motor Vehicles Using Compressed Natural Gas (CNG) in their Propulsion System; II. Vehicles with Regard to the Installation of Specific Components of an Approved Type for the Use of Compressed Natural Gas (CNG) in their Propulsion System.
Country:ECE - United Nations
Date of Issue:2001-06-19
Amendment Level:00 Series, Supplement 9
Number of Pages:153
Vehicle Types:Bus, Car, Component, Heavy Truck, Light Truck
Subject Categories:Prior Versions
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Keywords:

pressure, test, cylinder, temperature, paragraph, annex, cylinders, requirements, type, approval, accordance, material, gas, valve, maximum, cng, iso, design, tensile, tests, mpa, hours, regulation, working, appendix, strength, burst, system, service, elongation, operating, minimum, change, hose, component, components, liner, stress, conditions, tested, temperatures, vehicle, batch, device, resistance, method, break, relief, meet, manufacturer

Text Extract:

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E/ECE/324 )
Rev 2/Add.109/Rev.1/Amend.2
E/ECE/TRANS/505 )
October 4, 2010
STATUS OF UNITED NATIONS REGULATION
ECE 110-00
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF:
I. SPECIFIC COMPONENTS OF MOTOR VEHICLES USING COMPRESSED NATURAL
GAS (CNG) IN THEIR PROPULSION SYSTEM;
II.
VEHICLES WITH REGARD TO THE INSTALLATION OF SPECIFIC COMPONENTS
OF AN APPROVED TYPE FOR THE USE OF COMPRESSED NATURAL GAS (CNG)
IN THEIR PROPULSION SYSTEM
Incorporating:
00 series of amendments
Date of Entry into Force: 28.12.00
Corr. 1 to the 00 series of amendments
Dated : 08.11.00
Corr. 2 to the 00 series of amendments
Dated: 27.06.01
Supplement 1 to the 00 series of amendments
Date of Entry into Force: 31.01.03
Supplement 2 to the 00 series of amendments
Date of Entry into Force: 27.02.04
Supplement 3 to the 00 series of amendments
Date of Entry into Force: 12.08.04
Supplement 4 to the 00 series of amendments
Date of Entry into Force: 04.07.06
Supplement 5 to the 00 series of amendments
Date of Entry into Force: 02.02.07
Supplement 6 to the 00 series of amendments
Date of Entry into Force: 18.06.07
Supplement 7 to the 00 series of amendments
Date of Entry into Force: 03.02.08
Supplement 8 to the 00 series of amendments
Date of Entry into Force: 22.07.09
Supplement 9 to the 00 series of amendments
Date of Entry into Force: 19.08.10

REGULATION NO. 110
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF:
I. SPECIFIC COMPONENTS OF MOTOR VEHICLES USING COMPRESSED NATURAL GAS
(CNG) IN THEIR PROPULSION SYSTEM;
II.
VEHICLES WITH REGARD TO THE INSTALLATION OF SPECIFIC COMPONENTS OF AN
APPROVED TYPE FOR THE USE OF COMPRESSED NATURAL GAS (CNG) IN THEIR
PROPULSION SYSTEM
CONTENTS
REGULATION
1.
Scope
2.
Definition and classification of components
PART I.
3.
Application for approval
4.
Markings
5.
Approval
6.
Specifications regarding CNG components
7.
Modifications of a type of CNG component and extension of approval
8.
(Not allocated)
9.
Conformity of production
10.
Penalties for non-conformity of production
11.
(Not allocated)
12.
Production definitely discontinued
13.
Names and addresses of Technical Services responsible for conducting approval tests, and of
Administrative Departments
PART II
14.
Definitions
15.
Application of approval
16.
Approval
17.
Requirements for the installation of specific components for the use of compressed natural gas in
the propulsion system of a vehicle
18.
Conformity of production
19.
Penalties for non-conformity of production
20.
Modification and extension of approval of a vehicle type
21.
Production definitely discontinued
22.
Names and addresses of Technical Services responsible for conducting approval tests, and of
Administrative Departments

Annex 5
– Test procedures
Annex 5A – Overpressure test (Strength test)
Annex 5B – External leakage test
Annex 5C – Internal leakage test
Annex 5D – CNG compatibility test
Annex 5E – Corrosion resistance test
Annex 5F – Resistance to dry-heat
Annex 5G – Ozone ageing
Annex 5H – Temperature cycle test
Annex 5I – Pressure cycle test applicable only to cylinders (see Annex 3)
Annex 5J – (Not allocated)
Annex 5K – (Not allocated)
Annex 5L – Durability test (Continued operation)
Annex 5M – Burst/destructive test applicable only to cylinders (see Annex 3)
Annex 5N – Vibration resistance test
Annex 5O – Operating temperatures
Annex 6
– Provisions regarding CNG identification mark for public service vehicles

2.1.2. "Test pressure" means the pressure to which a component is taken during acceptance
testing.
2.1.3. "Working pressure" means the maximum pressure to which a component is designed to be
subjected to and which is the basis for determining the strength of the component under
consideration.
2.1.4. "Operating temperatures" means maximum values of the temperature ranges, indicated in
Annex 5O, at which safe and good functioning of the specific component is ensured and for
which it has been designed and approved.
2.2. "Specific component" means:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
(l)
(m)
(n)
(o)
(p)
(q)
(r)
(s)
(t)
(u)
(v)
container (or cylinder),
accessories fitted to the cylinder
pressure regulator,
automatic valve,
manual valve,
gas supply device,
gas flow adjuster,
flexible fuel line,
rigid fuel line,
filling unit or receptacle,
non-return valve,
pressure relief valve (discharge valve),
pressure relief device (temperature triggered),
filter,
pressure or temperature sensor/indicator,
excess flow valve,
service valve,
electronic control unit,
gas-tight housing,
fitting,
ventilation hose,
pressure relief device (PRD) (pressure triggered).

Performance
Test
Over-pressure
Strength Test
Leakage
Test
(external)
Leakage
Test
(internal)
Continued
Operation
Durability
Test
Corrosion
Resistance
Ozone
Ageing
CNG
Compatibility
Vibration
Resistance
Dry - Heat
Resistance
Annex 5A Annex 5B Annex 5C Annex 5L Annex 5E Annex 5G Annex 5D Annex 5N Annex 5F
Class 0 X X A A X X X X X
Class 1 X X A A X X X X X
Class 2 X X A A X A X X A
Class 3 X X A A X X X X X
Class 4 O O O O X A X O A
X = Applicable
O = Not applicable
A = As applicable
Figure 1-2
Tests Applicable to Specific Classes of Components (Excluding Cylinders)

2.15. "Fitting" means a connector used in a piping, tubing, or hose system.
2.16. Fuel Lines
2.16.1. "Flexible fuel lines" mean a flexible tubing or hose through which natural gas flow.
2.16.2. "Rigid fuel lines" mean a tubing which has not been designed to flex in normal operation
and through which natural gas flows.
2.17. "Gas supply device" means a device for introducing gaseous fuel into the engine intake
manifold (carburettor or injector).
2.17.1. "Gas/air mixer" means a device for mixing the gaseous fuel and intake air for the engine.
2.17.2. "Gas injector" means a device for introducing gaseous fuel into the engine or associated
intake system.
2.18. "Gas flow adjuster" means a gas flow restricting device, installed downstream of a pressure
regulator, controlling gas flow to the engine.
2.19. "Gas-tight housing" means a device which vents gas leakage to outside the vehicle
including the gas ventilation hose.
2.20. "Pressure indicator" means a pressurised device which indicates the gas pressure.
2.21. "Pressure regulator" means a device used to control the delivery pressure of gaseous fuel
to the engine.
2.22. "Pressure relief device (PRD) (temperature triggered)" means a one time use device
triggered by excessive temperature which vents gas to protect the cylinder from rupture.
2.23. "Filling unit or receptacle" means a device fitted in the vehicle external or internal (engine
compartment) used to fill the container in the filling station.
2.24. "Electronic control unit (CNG - fuelling)" means a device which controls the gas demand
of the engine, and other engine parameters, and cuts off automatically the automatic valve,
required by safety reason.
2.25. "Type of components" as mentioned in Paragraphs 2.6. to 2.23. above means components
which do not differ in such essential respect as materials, working pressure and operating
temperatures.
2.26. "Type of Electronic Control Unit" as mentioned in Paragraph 2.24. means components
which do not differ in such essential respect as the basic software principles excluding minor
changes.
2.27. "Pressure Relief Device (PRD) (pressure triggered) (this device sometimes is referred
to as "burst disc") means a one time use device triggered by excessive pressure which
prevents a pre-determined upstream pressure being exceeded.

4.3. Every container shall also bear a marking plate with the following data clearly legible and
indelible:
(a)
(b)
(c)
(d)
(e)
a serial number;
the capacity in litres;
the marking "CNG";
operating pressure/test pressure [MPa];
mass (kg);
(f) year and month of approval (e.g. 96/ 01);
(g) approval mark according to Paragraph 5.4.
5. APPROVAL
5.1. If the component samples submitted for approval meet the requirements of Paragraphs 6.1. to
6.11. of this Regulation, approval of the type of component shall be granted.
5.2. An approval number shall be assigned to each type of component or multifunctional
component approved. Its first two digits (at present 00 for the Regulation in its original form)
shall indicate the series of amendments incorporating the most recent major technical
amendments made to the Regulation at the time of issue of the approval. The same
Contracting Party shall not assign the same alphanumeric code to another type of
component.
5.3. Notice of approval or of refusal or of extension of approval of a CNG component type
pursuant to this Regulation shall be communicated to the Parties to the Agreement applying
this Regulation, by means of a form conforming to the model in Annex 2B to this Regulation.

6.2. Provisions Regarding Containers
6.2.1. The CNG containers shall be type-approved pursuant to the provisions laid down in Annex 3
to this Regulation.
6.3. Provisions Regarding Components Fitted to the Container
6.3.1. The container shall be equipped at least with the following components, which may be either
separate or combined:
6.3.1.1. manual valve,
6.3.1.2. automatic cylinder valve,
6.3.1.3. pressure relief device,
6.3.1.4. excess flow limiting device.
6.3.2. The container may be equipped with a gas-tight housing, if necessary.
6.3.3. The components mentioned in Paragraphs 6.3.1. to 6.3.2. above shall be type-approved
pursuant to the provisions laid down in Annex 4 to this Regulation.
6.4.-6.11. Provisions Regarding other Components
The components shown shall be type-approved pursuant to the provisions laid down in the
annexes which can be determined from the table below:
Paragraph
Component
Annex
6.4.
Automatic value
4A
Check valve or non-return valve
Pressure relief valve
Pressure relief device (temperature triggered)
Excess flow valve
Pressure relief device (pressure triggered)
6.5.
Flexible fuel line-hose
4B
6.6.
CNG filter
4C
6.7.
Pressure regulator
4D
6.8.
Pressure and temperature sensors
4E
6.9.
Filling unit or receptacle
4F
6.10.
Gas flow adjuster and gas/air mixer or injector
4G
6.11.
Electronic control unit
4H

11. (NOT ALLOCATED)
12. PRODUCTION DEFINITELY DISCONTINUED
If the holder of the approval completely ceases to manufacture a type of component approved
in accordance with this Regulation, he shall so inform the authority which granted the
approval. Upon receiving the relevant communication, that authority shall inform thereof the
other Parties to the Agreement applying this Regulation by means of a communication form
conforming to the model in Annex 2B to this Regulation.
13. NAMES AND ADDRESSES OF TECHNICAL SERVICES RESPONSIBLE FOR
CONDUCTING APPROVAL TESTS, AND OF ADMINISTRATIVE DEPARTMENTS
The Parties to the Agreement applying this Regulation shall communicate to the United
Nations Secretariat the names and addresses of the Technical Services responsible for
conducting approval tests and of the Administrative Departments which grant approval and to
which forms certifying approval or extension or refusal or withdrawal of approval, issued in
other countries, are to be sent.
PART II
APPROVAL OF VEHICLES WITH REGARD TO THE INSTALLATION OF
SPECIFIC COMPONENTS OF AN APPROVED TYPE FOR
THE USE OF COMPRESSED NATURAL GAS (CNG) IN THEIR PROPULSION SYSTEM
14. DEFINITIONS
14.1. For the purposes of Part II of this Regulation:
14.1.1. "Approval of a vehicle" means the approval of a vehicle type of Categories M and N with
regard to its CNG system as an original equipment for the use in its propulsion system;
14.1.2. "Vehicle type" means vehicles fitted with specific components for the use of CNG in their
propulsion system which do not differ with respect to the following conditions:
14.1.2.1. the manufacturer;
14.1.2.2. the type designation established by the manufacturer,
14.1.2.3. the essential aspects of design and construction:
14.1.2.3.1. chassis/ floor pan (obvious and fundamental differences);
14.1.2.3.2. the installation of the CNG equipment (obvious and fundamental differences).
14.1.3. "CNG system" means an assembly of components (container(s) or cylinder(s), valves,
flexible fuel lines, etc.) and connecting parts (rigid fuel lines, pipes fitting, etc.) fitted on
motor vehicles using CNG in their propulsion system.

16.5. If the vehicle conforms to a vehicle approved, under one or more other Regulations annexed
to the Agreement, in the country which has granted approval under this Regulation, the
symbol prescribed in Paragraph 16.4.1. need not be repeated; in such case, the Regulation
and approval numbers and the additional symbols of all the Regulations under which
approval has been granted in the country which has granted approval under this Regulation
shall be placed in vertical columns to the right of the symbol prescribed in Paragraph 16.4.1.
16.6. The approval mark shall be clearly legible and be indelible.
16.7. The approval mark shall be placed close to or on the vehicle data plate.
16.8. Annex 2C to this Regulation gives examples of the arrangement of the aforesaid approval
mark.
17. REQUIREMENTS FOR THE INSTALLATION OF SPECIFIC COMPONENTS FOR THE
USE OF COMPRESSED NATURAL GAS IN THE PROPULSION SYSTEM OF A VEHICLE
17.1. General
17.1.1. The CNG system of the vehicle shall function in a good and safe manner at the working
pressure and operating temperatures for which it has been designed and approved.
17.1.2. All components of the system shall be type-approved as individual parts pursuant to Part I of
this Regulation.
17.1.3. The materials used in the system shall be suitable for use with CNG.
17.1.4. All components of the system shall be fastened in a proper way.
17.1.5. The CNG system shall show no leaks, i.e. stay bubble-free for 3 minutes.
17.1.6. The CNG system shall be installed such that it has the best possible protection against
damage, such as damage due to moving vehicle components, collision, grit or due to the
loading or unloading of the vehicle or the shifting of those loads.
17.1.7. No appliances shall be connected to the CNG system other than those strictly required for
the proper operation of the engine of the motor vehicle.
17.1.7.1. Notwithstanding the provisions of Paragraph 17.1.7., vehicles may be fitted with a heating
system to heat the passenger compartment and/or the load area which is connected to the
CNG system.
17.1.7.2. The heating system referred to in Paragraph 17.1.7.1. shall be permitted if, in the view of the
Technical Services responsible for conducting type-approval, the heating system is
adequately protected and the required operation of the normal CNG system is not affected.
17.1.8. Identification of CNG-Fuelled Vehicles of Categories M and M .
17.1.8.1. Vehicles of Categories M and M equipped with a CNG system shall carry a plate as
specified in Annex 6.

17.3.2.3. CNG filter;
17.3.2.4. Pressure and/or temperature sensor;
17.3.2.5. Fuel selection system and electrical system;
17.3.2.6. PRD (pressure triggered).
17.3.3. An additional automatic valve may be combined with the pressure regulator.
17.4. Installation of the Container
17.4.1. The container shall be permanently installed in the vehicle and shall not be installed in the
engine compartment.
17.4.2. The container shall be installed such that there is no metal to metal contact, with the
exception of the fixing points of the container(s).
17.4.3. When the vehicle is ready for use the fuel container shall not be less than 200 mm above
the road surface.
17.4.3.1. The provisions of Paragraph 17.4.3. shall not apply if the container is adequately protected,
at the front and the sides and no part of the container is located lower than this protective
structure.
17.4.4. The fuel container(s) or cylinder(s) must be mounted and fixed so that the following
accelerations can be absorbed (without damage occurring) when the containers are full:
Vehicles of Categories M and N :
(a)
(b)
20 g in the direction of travel
8 g horizontally perpendicular to the direction of travel
Vehicles of Categories M and N :
(a)
(b)
10 g in the direction of travel
5 g horizontally perpendicular to the direction of travel
Vehicles of Categories M and N :
(a)
(b)
6.6 g in the direction of travel
5 g horizontally perpendicular to the direction of travel
A calculation method can be used instead of practical testing if its equivalence can be
demonstrated by the applicant for approval to the satisfaction of the Technical Service.

17.5.6. PRD (Pressure Triggered)
17.5.6.1. The PRD (pressure triggered) shall be activated and shall vent the gas independently from
the PRD (temperature triggered).
17.5.6.2. The PRD (pressure triggered) shall be fitted to the fuel container(s) in such a manner that it
can discharge into the gas-tight housing if that gas-tight housing fulfils the requirements of
Paragraph 17.5.5.
17.6. Rigid and Flexible Fuel Lines
17.6.1. Rigid fuel lines shall be made of seamless material: either stainless steel or steel with
corrosion-resistant coating.
17.6.2. The rigid fuel line may be replaced by a flexible fuel line if used in Class 0, 1 or 2.
17.6.3. Flexible fuel line shall fulfil the requirement of Annex 4B to this Regulation.
17.6.4. Rigid fuel lines, shall be secured such that they shall not be subjected to vibration or
stresses.
17.6.5. Flexible fuel lines shall be secured such that they shall not be subjected to vibration or
stresses.
17.6.6. At the fixing point, the fuel line, flexible or rigid, shall be fitted in such a way that there is no
metal to metal contact.
17.6.7. Rigid and flexible fuel gas line shall not be located at jacking points.
17.6.8. At passages the fuel lines shall be fitted with protective material.
17.7. Fitting or Gas Connections Between the Components
17.7.1. Soldered joints and bite-type compression joints are not permitted.
17.7.2. Stainless steel tubes shall only be joined by stainless steel fittings.
17.7.3. Distributing-blocks shall be made of corrosion-resistant material.
17.7.4. Rigid fuel lines shall be connected by appropriate joints, for example, two-part compression
joints in steel tubes and joints with olives tapered on both sides.
17.7.5. The number of joints shall be limited to a minimum.
17.7.6. Any joints shall be made in locations where access is possible for inspection.
17.7.7. In a passenger compartment or enclosed luggage compartment the fuel lines shall be no
longer than reasonably required, and in any case shall be protected by a gas-tight housing.
17.7.7.1. The provisions of Paragraph 17.7.7. shall not apply to vehicles of Categories M or M
where the fuel lines and connections are fitted with a sleeve which is resistant against CNG
and which has an open connection to the atmosphere.

20. MODIFICATION AND EXTENSION OF APPROVAL OF A VEHICLE TYPE
20.1. Every modification of the installation of the specific components for the use of compressed
natural gas in the propulsion system of the vehicle shall be notified to the administrative
department which approved the vehicle type. The department may then either:
20.1.1. Consider that the modifications made are unlikely to have an appreciably adverse effect and
that in any case the vehicle still complies with the requirements; or
20.1.2. Require a further test report from the Technical Service responsible for conducting the tests.
20.2. Confirmation or refusal of approval, specifying the alteration, shall be communicated to the
Parties to the Agreement applying this Regulation by means of a form conforming to the
model in Annex 2D to this Regulation.
20.3. The competent authority issuing the extension of approval shall assign a series number for
such an extension and inform thereof the other Parties to the 1958 Agreement applying this
Regulation by means of a communication form conforming to the model in Annex 2D to this
Regulation.
21. PRODUCTION DEFINITELY DISCONTINUED
If the holder of the approval completely ceases to manufacture a type of vehicle approved in
accordance with this Regulation, he shall so inform the authority which granted the
approval. Upon receiving the relevant communication, that authority shall inform thereof the
other Parties to the Agreement applying this Regulation by means of a communication form
conforming to the model in Annex 2D to this Regulation.
22. NAMES AND ADDRESSES OF TECHNICAL SERVICES RESPONSIBLE FOR
CONDUCTING APPROVAL TESTS, AND OF ADMINISTRATIVE DEPARTMENTS
The Parties to the Agreement applying this Regulation shall communicate to the United
Nations Secretariat the names and addresses of the Technical Services responsible for
conducting approval tests and of the administrative departments which grant approval and
to which forms certifying approval or extension or refusal or withdrawal of approval, issued
in other countries, are to be sent.

1.2.4.5.4.
Gas flow adjuster: yes/no
1.2.4.5.4.1.
Number:...................................................................................................................................
1.2.4.5.4.2.
Make(s):...................................................................................................................................
1.2.4.5.4.3.
Type(s): ...................................................................................................................................
1.2.4.5.4.4.
Drawings:.................................................................................................................................
1.2.4.5.4.5.
Adjustment possibilities (description)
1.2.4.5.4.6.
Working pressure(s):
....................................................................................................kPa
1.2.4.5.4.7.
Material:...................................................................................................................................
1.2.4.5.4.8.
Operating temperatures:
................................................................................................. °C
1.2.4.5.5.
Gas injector(s): yes/no
1.2.4.5.5.1.
Make(s):...................................................................................................................................
1.2.4.5.5.2.
Type(s): ...................................................................................................................................
1.2.4.5.5.3.
Identification: ...........................................................................................................................
1.2.4.5.5.4.
Working pressure(s):
.....................................................................................................kPa
1.2.4.5.5.5.
Drawings of installation:...........................................................................................................
1.2.4.5.5.6.
Material:...................................................................................................................................
1.2.4.5.5.7.
Operating temperatures:
................................................................................................. °C
1.2.4.5.6.
Electronic Control Unit (CNG-fuelling): yes/no
1.2.4.5.6.1.
Make(s):...................................................................................................................................
1.2.4.5.6.2.
Type(s): ...................................................................................................................................
1.2.4.5.6.3.
Adjustment possibilities: ..........................................................................................................
1.2.4.5.6.4.
Basic software principles:........................................................................................................
1.2.4.5.6.5.
Operating temperatures:
................................................................................................. °C

1.2.4.5.8.3.3.
Working pressure(s)
:..................................................................................................MPa
1.2.4.5.8.3.4.
Material: ................................................................................................................................
1.2.4.5.8.3.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.8.4.
Excess flow valve: yes/no
1.2.4.5.8.4.1
Make(s): ................................................................................................................................
1.2.4.5.8.4.2
Type(s):.................................................................................................................................
1.2.4.5.8.4.3
Working pressure(s)
:..................................................................................................MPa
1.2.4.5.8.4.4.
Material: ................................................................................................................................
1.2.4.5.8.4.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.8.5.
Gas-tight housing: yes/no
1.2.4.5.8.5.1
Make(s): ................................................................................................................................
1.2.4.5.8.5.2
Type(s):.................................................................................................................................
1.2.4.5.8.5.3
Working pressure(s)
:..................................................................................................MPa
1.2.4.5.8.5.4.
Material: ................................................................................................................................
1.2.4.5.8.5.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.8.6.
Manual valve: yes/no
1.2.4.5.8.6.1
Make(s): ................................................................................................................................
1.2.4.5.8.6.2
Type(s):.................................................................................................................................
1.2.4.5.8.6.3
Drawings: ..............................................................................................................................
1.2.4.5.8.6.4
Working pressure(s)
:..................................................................................................MPa
1.2.4.5.8.6.5.
Material: ................................................................................................................................
1.2.4.5.8.6.6.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.9.
Pressure relief device (temperature triggered): yes/ no
1.2.4.5.9.1.
Make(s): ................................................................................................................................
1.2.4.5.9.2.
Type(s):.................................................................................................................................

1.2.4.5.13.
CNG filter(s): yes/no
1.2.4.5.13.1.
Make(s): ................................................................................................................................
1.2.4.5.13.2.
Type(s):.................................................................................................................................
1.2.4.5.13.3.
Description: ...........................................................................................................................
1.2.4.5.13.4.
Working pressure(s):
..................................................................................................kPa
1.2.4.5.13.5.
Material: ................................................................................................................................
1.2.4.5.13.6.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.14.
Non-return valve(s) : yes/no
1.2.4.5.14.1.
Make(s): ................................................................................................................................
1.2.4.5.14.2.
Type(s):.................................................................................................................................
1.2.4.5.14.3.
Description: ...........................................................................................................................
1.2.4.5.14.4.
Working pressure(s) :
.................................................................................................kPa
1.2.4.5.14.5.
Material: ................................................................................................................................
1.2.4.5.14.6.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.15.
Connection to CNG system for heating system : yes/no
1.2.4.5.15.1.
Make(s): ................................................................................................................................
1.2.4.5.15.2.
Type(s):.................................................................................................................................
1.2.4.5.15.3.
Description and drawings of installation:
1.2.4.5.16.
PRD (pressure triggered): yes/no
1.2.4.5.16.1.
Make(s): ...............................................................................................................................
1.2.4.5.16.2.
Type(s): ................................................................................................................................
1.2.4.5.16.3.
Description and drawings: ...................................................................................................
1.2.4.5.16.4.
Activation pressure:
................................................................................................. MPa
1.2.4.5.16.5.
Material: ...............................................................................................................................
1.2.4.5.16.6.
Operating temperatures:
............................................................................................. °C
1.2.5.
Cooling system: (liquid/air)
1.2.5.1.
System description/ drawings with regard to the CNG system:

1.2.4.5.3.5.
Material: ................................................................................................................................
1.2.4.5.3.6.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.4.
Gas flow adjuster: yes/no
1.2.4.5.4.1.
Number: ................................................................................................................................
1.2.4.5.4.2.
Make(s): ................................................................................................................................
1.2.4.5.4.3.
Type(s):.................................................................................................................................
1.2.4.5.4.4.
Working pressure(s):
...................................................................................................kPa
1.2.4.5.4.5.
Material: ................................................................................................................................
1.2.4.5.4.6.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.5.
Gas injector(s): yes/no
1.2.4.5.5.1.
Make(s): ................................................................................................................................
1.2.4.5.5.2.
Type(s):.................................................................................................................................
1.2.4.5.5.3.
Working pressure(s):
...................................................................................................kPa
1.2.4.5.5.4.
Material: ................................................................................................................................
1.2.4.5.5.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.6.
Electronic Control Unit CNG-fuelling: yes/no
1.2.4.5.6.1.
Make(s): ................................................................................................................................
1.2.4.5.6.2.
Type(s):.................................................................................................................................
1.2.4.5.6.3.
Basic software principles: .....................................................................................................
1.2.4.5.6.4.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.7.
CNG container(s) or cylinder(s): yes/no
1.2.4.5.7.1.
Make(s): ................................................................................................................................
1.2.4.5.7.2.
Type(s):.................................................................................................................................
1.2.4.5.7.3.
Capacity: ....................................................................................................................... litres
1.2.4.5.7.4.
Approval number:..................................................................................................................

1.2.4.5.8.4.4.
Material: ................................................................................................................................
1.2.4.5.8.4.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.8.5.
Gas-tight housing: yes/no
1.2.4.5.8.5.1
Make(s): ................................................................................................................................
1.2.4.5.8.5.2
Type(s):.................................................................................................................................
1.2.4.5.8.5.3.
Working pressure(s)
:..................................................................................................MPa
1.2.4.5.8.5.4.
Material: ................................................................................................................................
1.2.4.5.8.5.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.8.6.
Manual valve:
1.2.4.5.8.6.1
Make(s): ................................................................................................................................
1.2.4.5.8.6.2
Type(s):.................................................................................................................................
1.2.4.5.8.6.3
Working pressure(s)
...................................................................................................MPa
1.2.4.5.8.6.4.
Material: ................................................................................................................................
1.2.4.5.8.6.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.9.
Pressure relief device (temperature triggered): yes/no
1.2.4.5.9.1.
Make(s): ................................................................................................................................
1.2.4.5.9.2.
Type(s):.................................................................................................................................
1.2.4.5.9.3.
Activation temperature:
................................................................................................ °C
1.2.4.5.9.4.
Material: ................................................................................................................................
1.2.4.5.9.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.10.
Filling unit or receptacle: yes/no
1.2.4.5.10.1.
Make(s): ................................................................................................................................
1.2.4.5.10.2.
Type(s):.................................................................................................................................
1.2.4.5.10.3.
Working pressure(s)
: .................................................................................................MPa

1.2.4.5.14.4.
Material: ................................................................................................................................
1.2.4.5.14.5.
Operating temperatures:
.............................................................................................. °C
1.2.4.5.15.
Connection to CNG system for heating system : yes/no
1.2.4.5.15.1.
Make(s): ................................................................................................................................
1.2.4.5.15.2.
Type(s):.................................................................................................................................
1.2.4.5.15.3.
Description and drawings of installation: ..............................................................................
1.2.4.5.16.
PRD (pressure triggered): yes/no
1.2.4.5.16.1.
Make(s): ...............................................................................................................................
1.2.4.5.16.2.
Type(s): ................................................................................................................................
1.2.4.5.16.3.
Activation pressure:
................................................................................................. MPa
1.2.4.5.16.4.
Material: ...............................................................................................................................
1.2.4.5.16.5.
Operating temperatures:
............................................................................................. °C
1.2.4.5.17.
Further documentation: ........................................................................................................
1.2.4.5.17.1.
Description of the CNG system
1.2.4.5.17.2.
System lay-out (electrical connections, vacuum connections compensation hoses, etc.):
1.2.4.5.17.3.
Drawing of the symbol:
1.2.4.5.17.4.
Adjustment data: ...................................................................................................................
1.2.4.5.17.5.
Certificate of the vehicle on petrol, if already granted: .........................................................
1.2.5.
Cooling system: (liquid/air)

ANNEX 2B
COMMUNICATION
(maximum format: A4 (210 x 297 mm))
issued by:
Name of administration:
.............................................
.............................................
.............................................
concerning:
APPROVAL GRANTED
APPROVAL EXTENDED
APPROVAL REFUSED
APPROVAL WITHDRAWN
PRODUCTION DEFINITELY DISCONTINUED
of a type of CNG component pursuant to Regulation No. 110
Approval No.:...................................................... Extension No.: .........................................................
1. CNG component considered:
Container(s) or cylinder(s)
Pressure indicator
Pressure relief valve
Automatic valve(s)
Excess flow valve
Gas-tight housing
Pressure regulator(s)
Non-return valve(s)
Pressure relief device (PRD) (temperature triggered)
Manual valve
Flexible fuel lines
Filling unit or receptacle
Gas injector(s)
Gas flow adjuster
Gas/air mixer
Electronic control unit
Pressure and temperature sensor(s)
CNG filter(s)
PRD (pressure triggered)

ANNEX 2B
ADDENDUM
1. ADDITIONAL INFORMATION CONCERNING THE TYPE-APPROVAL OF A TYPE OF CNG
COMPONENTS PURSUANT TO REGULATION NO 110
1.1.
Container(s) or Cylinder(s)
1.1.1.
Dimensions:.....................................................................................................................................
1.1.2.
Material:...........................................................................................................................................
1.2.
Pressure Indicator
1.2.1.
Working pressure(s):
..................................................................................................................
1.2.2.
Material:...........................................................................................................................................
1.3.
Pressure Relief Valve (Discharge Valve)
1.3.1.
Working pressure(s):
...................................................................................................................
1.3.2.
Material:...........................................................................................................................................
1.4.
Automatic Valve(s)
1.4.1.
Working pressure(s):
..................................................................................................................
1.4.2.
Material:...........................................................................................................................................
1.5.
Excess Flow Valve
1.5.1.
Working pressure(s):
..................................................................................................................
1.5.2.
Material:...........................................................................................................................................
1.6.
Gas-tight Housing
1.6.1.
Working pressure(s):
..................................................................................................................
1.6.2.
Material:...........................................................................................................................................
1.7.
Pressure Regulator(s)
1.7.1.
Working pressure(s):
..................................................................................................................
1.7.2.
Material:...........................................................................................................................................

1.17.
Pressure and Temperature Sensor(s)
1.17.1.
Working pressure(s):
..................................................................................................................
1.17.2.
Material:...........................................................................................................................................
1.18.
CNG Filter(s)
1.18.1.
Working pressure(s):
..................................................................................................................
1.18.2.
Material:...........................................................................................................................................
1.19.
PRD (Pressure Triggered)
1.19.1.
Working pressure(s):
.......................................................................................................... MPa
1.19.2.
Material: ..........................................................................................................................................

ANNEX 2D
COMMUNICATION
(maximum format: A4 (210 x 297 mm))
issued by:
Name of administration:
.............................................
.............................................
.............................................
concerning:
APPROVAL GRANTED
APPROVAL EXTENDED
APPROVAL REFUSED
APPROVAL WITHDRAWN
PRODUCTION DEFINITELY DISCONTINUED
of a vehicle type with regard to the installation of CNG system pursuant to Regulation No. 110
Approval No.:......................................................
Extension No.: .........................................................
1.
Trade name or mark of vehicle:.........................................................................................................
2.
Vehicle type: ......................................................................................................................................
3.
Vehicle category: ...............................................................................................................................
4.
Manufacturer's name and address: ...................................................................................................
5.
If applicable, name and address of manufacturer's representative:..................................................
6.
Description of the vehicle, drawings, etc. (needs detailing): .............................................................
7.
Test results: .......................................................................................................................................
8.
Vehicle submitted for approval on: ....................................................................................................
9.
Technical Service responsible for conducting approval tests:...........................................................
10.
Date of report issued by that service: ................................................................................................
11.
CNG system
11.1.
Trade name or mark of components and their approval numbers:.................................................
11.1.1.
Container(s) or cylinder(s):..............................................................................................................

ANNEX 3
GAS CYLINDERS − HIGH PRESSURE CYLINDER FOR THE ON-BOARD STORAGE OF
NATURAL GAS AS A FUEL FOR AUTOMOTIVE VEHICLES
1. SCOPE
This annex sets out minimum requirements for light-weight refillable gas cylinders. The
cylinders are intended only for the on-board storage of high pressure compressed natural gas
as a fuel for automotive vehicles to which the cylinders are to be fixed. Cylinders may be of
any steel, aluminium or non-metallic material, design or method of manufacture suitable for the
specified service conditions. This annex also covers stainless steel metal liners of seamless or
welded construction. Cylinders covered by this annex are Classified in Class 0, as described in
Paragraph 2. of this Regulation, and are:
CNG-1
CNG-2
CNG-3
CNG-4
Metal
Metal liner reinforced with resin impregnated continuous filament (hoop wrapped)
Metal liner reinforced with resin impregnated continuous filament (fully wrapped)
Resin impregnated continuous filament with a non-metallic liner (all composite)
Service conditions to which the cylinders will be subjected are detailed in Paragraph 4. This
annex is based upon a working pressure for natural gas as a fuel of 20 MPa settled at 15°C
with a maximum filling pressure of 26 MPa. Other working pressures can be accommodated
by adjusting the pressure by the appropriate factor (ratio). For example, a 25 MPa working
pressure system will require pressures to be multiplied by 1.25.
The service life of the cylinder shall be defined by the manufacturer and may vary with
applications. Definition of service life is based upon filling the cylinders 1,000 times a year for a
minimum of 15,000 fills. The maximum service life shall be 20 years.
For metal and metal-lined cylinders, the cylinder life is based upon the rate of fatigue crack
growth. The ultrasonic inspection, or equivalent, of each cylinder or liner is required to ensure
the absence of flaws which exceed the maximum allowable size. This approach permits the
optimised design and manufacture of light weight cylinders for natural gas vehicle service.
For all-composite cylinders with non-metallic non-load bearing liners the "safe life" is
demonstrated by appropriate design methods, design qualification testing and manufacturing
controls.

ISO Standards
ISO 148-1983
ISO 306-1987
ISO 527 Pt 1-93
ISO 642-79
ISO 2808-91
ISO 3628-78
ISO 4624-78
ISO 6982-84
ISO 6506-1981
ISO 6508-1986
ISO 7225
ISO/DIS 7866-1992
Steel - Charpy Impact Test (v-notch);
Plastics - Thermoplastic Materials - Determination of Vicat
Softening Temperature ;
Plastics - Determination of Tensile Properties - Part I: General
principles;
Steel-Hardenability Test by End Quenching (Jominy Test);
Paints and Varnishes - Determination of film Thickness;
Glass Reinforced Materials - Determination of Tensile Properties
Plastics and Varnishes - Pull-off Test for adhesion;
Metallic Materials - Tensile Testing,
Metallic Materials - Hardness test - Brinell Test;
Metallic Materials - Hardness Tests - Rockwell Test (Scales,
ABCDEFGHK);
Precautionary Labels for Gas Cylinders,
Refillable Transportable Seamless Aluminium Alloy Cylinders for
Worldwide Usage Design, Manufacture and Acceptance;
ISO 9001:1994 Quality Assurance in Design/Development. Production,
Installation and Servicing;
ISO 9002:1994
ISO/DIS 12737
ISO/IEC Guide 25-1990
ISO/IEC Guide 48-1986
Quality Assurance in Production and Installation;
Metallic Materials - Determination of the Plane-Strain Fracture
Toughness;
General requirements for the Technical Competence of Testing
Laboratories;
Guidelines for Third Party Assessment and Registration of
Supplies Quality System;
ISO/DIS 9809 Transportable Seamless Steel Gas Cylinders Design,
Construction and Testing - Part I: Quenched and Tempered Steel
Cylinders with Tensile Strength < 1100 MPa;
NACE Standard
NACE TM0177-90
Laboratory Testing of Metals for Resistance to Sulphide Stress
Cracking in H S Environments.

3.14. hoop-wrap: An over-wrap having a filament wound reinforcement in a substantially
circumferential pattern over the cylindrical portion of the liner so that the filament does not carry
any significant load in a direction parallel to the cylinder longitudinal axis.
3.15. liner: A container that is used as a gas-tight, inner shell, on which reinforcing fibres are
filament wound to reach the necessary strength. Two types of liners are described in this
standard: Metallic liners that are designed to share the load with the reinforcement, and
non-metallic liners that do not carry any part of the load.
3.16. manufacturer: The person or organisation responsible for the design, fabrication and testing of
the cylinders.
3.17. maximum developed pressure: The settled pressure developed when gas in a cylinder filled
to the working pressure is raised to the maximum service temperature.
3.18. over-wrap: The reinforcement system of filament and resin applied over the liner.
3.19. prestressing: The process of applying auto-frettage or controlled tension winding.
3.20. service life: The life in years during which the cylinders may safely be used in accordance with
the standard service conditions.
3.21. settled pressure: The gas pressure when a given settled temperature is reached.
3.22. settled temperature: The uniform gas temperature after any change in temperature caused by
filling has dissipated.
3.23. test pressure: The pressure at which the cylinder is hydrostatically tested.
3.24. working pressure: The settled pressure of 20 MPa at a uniform temperature of 15°C.
4 SERVICE CONDITIONS
4.1. General
4.1.1. Standard Service Conditions
The standard service conditions specified in this section are provided as a basis for the design,
manufacture, inspection, testing, and approval of cylinders that are to be mounted permanently
on vehicles and used to store natural gas at ambient temperatures for use as a fuel on
vehicles.

4.2. Maximum Pressures
The cylinder pressure shall be limited to the following:
(a)
(b)
a pressure that would settle to 20 MPa at a settled temperature of 15°C;
26 MPa, immediately after filling, regardless of temperature;
4.3. Maximum Number of Filling Cycles
Cylinders are designed to be filled up to a settled pressure of 20 MPa bar at a settled gas
temperature of 15°C for up to 1,000 times per year of service.
4.4. Temperature Range
4.4.1. Settled Gas Temperature
Settled temperature of gas in cylinders may vary from a minimum of -40°C to a maximum of
65°C;
4.4.2. Cylinder Temperatures
The temperature of the cylinder materials may vary from a minimum of -40°C to a maximum of
+82°C;
Temperatures over +65°C may be sufficiently local, or of short enough duration, that the
temperature of gas in the cylinder never exceeds +65°C, except under the conditions of
Paragraph 4.4.3;
4.4.3. Transient Temperatures
Developed gas temperatures during filling and discharge may vary beyond the limits of
Paragraph 4.4.1;
4.5. Gas Composition
Methanol and/or glycol shall not be deliberately added to the natural gas. Cylinder should be
designed to tolerate being filled with natural gas meeting either of the following three
conditions:
(a)
(b)
SAE J1616
Dry gas
Water vapour would normally be limited to less than 32 mg/m a pressure dewpoint of
-9°C at 20 MPa. There would be no constituent limits for dry gas, except for:
Hydrogen sulfide and other soluble sulfides:
Oxygen:
23 mg/m
1% by volume
Hydrogen shall be limited to 2% by volume when cylinders are manufactured from a
steel with an ultimate tensile strength exceeding 950 MPa;

5. DESIGN APPROVAL
5.1. General
The following information shall be submitted by the cylinder designer with a request for
approval to the Competent Authority:
(a) statement of service (Paragraph 5.2.)
(b) design data (Paragraph 5.3.)
(c) manufacturing data (Paragraph 5.4.)
(d) quality system (Paragraph 5.5.)
(e) fracture performance and NDE (Non Destructive Examination) defect size
(Paragraph 5.6.);
(f) specification sheet (Paragraph 5.7.)
(g) additional supporting data (Paragraph 5.8.)
For cylinders designed in accordance with ISO 9809 it is not required to provide the stress
analysis report in Paragraph 5.3.2. or the information in Paragraph 5.6.
5.2. Statement of Service
The purpose of this statement of service is to guide users and installers of cylinders as well as
to inform the approving Competent Authority, or their designated representative. The
statement of service shall include:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
a statement that the cylinder design is suitable for use in the service conditions defined
in Paragraph 4 for the service life of the cylinder;
the service life;
the minimum in-service test and/or inspection requirements;
the pressure relief devices and/or insulation required;
support methods, protective coatings, etc., required but not provided;
a description of the cylinder design;
any other information necessary to ensure the safe use and inspection of the cylinder.

5.3.6. Cylinder Supports
Details of cylinder supports or support requirements shall be provided in accordance with
Paragraph 6.11.
5.4. Manufacturing Data
Details of all fabrication processes, non-destructive examinations, production tests and batch
tests shall be provided; The tolerances for all production processes such as heat treatment,
end forming, resin mix ratio, filament winding tension and speed, curing times and
temperatures, and auto-frettage procedures shall be specified; Surface finish, thread details,
acceptance criteria for ultrasonic scanning (or equivalent), and maximum lot sizes for batch
tests shall also be specified.
5.5. (Not Allocated)
5.6. Fracture Performance and NDE Defect Size
5.6.1. Fracture Performance
The manufacturer shall demonstrate the Leak-Before-Break performance of the design as
described in Paragraph 6.7.
5.6.2. NDE Defect Size
Using the approach described in Paragraph 6.15.2 the manufacturer shall establish the
maximum defect size for non-destructive examination which will prevent the failure of the
cylinder during its service life due to fatigue, or failure of the cylinder by rupture.
5.7. Specification Sheet
A summary of the documents providing the information required in Paragraph 5.1. shall be
listed on a specification sheet for each cylinder design. The title, reference number, revision
numbers and dates of original issue and version issues of each document shall be given. All
documents shall be signed or initialled by the issuer; The specification sheet shall be given a
number, and revision numbers if applicable, that can be used to designate the cylinder design
and shall carry the signature of the engineer responsible for the design. Space shall be
provided on the specification sheet for a stamp indicating registration of the design.
5.8. Additional Supporting Data
Additional data which would support the application, such as the service history of material
proposed for use, or the use of a particular cylinder design in other service conditions, shall be
provided where applicable.

6.3. Materials
6.3.1. Materials used shall be suitable for the service conditions specified in Paragraph 4. The design
shall not have incompatible materials in contact. The design qualification tests for materials are
summarised in Table 6.1.
6.3.2. Steel
6.3.2.1. Composition
Steels shall be aluminium and/or silicon killed and produced to predominantly fine grain
practice. The chemical composition of all steels shall be declared and defined at least by:
(a)
(b)
carbon, manganese, aluminium and silicon contents in all cases;
nickel, chromium, molybdenum, boron and vanadium contents, and any other alloying
elements intentionally added. The following limits shall not be exceeded in the cast
analysis:
Tensile strength
< 950 MPa
≥ 950 MPa
Sulfur
0.020%
0.010%
Phosphorus
0.020%
0.020%
Sulfur and Phosphorus
0.030%
0.025%
When a carbon-boron steel is used, a hardenability test in accordance with ISO 642, shall be
performed on the first and last ingot or slab of each heat of steel. The hardness as measured
in a distance of 7.9 mm from the quenched end, shall be within the range 33-53 HRC, or
327-560 HV, and shall be certified by the material manufacturer;
6.3.2.2. Tensile properties
The mechanical properties of the steel in the finished cylinder or liner shall be determined in
accordance with Paragraph A.1 (Appendix A). The elongation for steel shall be at least 14%;
6.3.2.3. Impact properties
The impact properties of the steel in the finished cylinder or liner shall be determined in
accordance with Paragraph A.2 (Appendix A). Impact values shall not be less than that
indicated in Table 6.2 of this annex;
6.3.2.4. Bending properties
The bending properties of the welded stainless steel in the finished liner shall be determined in
accordance with Paragraph A.3. (Appendix A).
6.3.2.5. Macroscopic weld examination
A macroscopic weld examination for each type of welding procedure shall be performed. It
shall show complete fusion and shall be free of any assembly faults or unacceptable defects as
specified according to level C in EN ISO 5817.

6.3.5. Fibres
Structural reinforcing filament material types shall be glass fibre, aramid fibre or carbon fibre. If
carbon fibre reinforcement is used the design shall incorporate means to prevent galvanic
corrosion of metallic components of the cylinder. The manufacturer shall keep on file the
published specifications for composite materials, the material manufacturer's recommendations
for storage, conditions and shelf life and the material manufacturer's certification that each
shipment conforms to said specification requirements. The fibre manufacturer shall certify that
the fibre material properties conform to the manufacturer's specifications for the product.
6.3.6 Plastic Liners
The tensile yield strength and ultimate elongation shall be determined in accordance with
Paragraph A.22 (Appendix A). Tests shall demonstrate the ductile properties of the plastic liner
material at temperatures of -50°C or lower by meeting the values specified by the
manufacturer; The polymeric material shall be compatible with the service conditions specified
in Paragraph 4 of this annex. In accordance with the method described in Paragraph A.23
(Appendix A), the softening temperature shall be at least 90°C, and the melting temperature at
least 100°C.
6.4. Test Pressure
The minimum test pressure used in manufacture shall be 30 MPa;
6.5. Burst Pressures and Fibre Stress Ratios
For all types of cylinder the minimum actual burst pressure shall not be less than the values
given in Table 6.3 of this annex. For Type CNG-2, CNG-3 and CNG-4 designs the composite
over-wrap shall be designed for high reliability under sustained loading and cyclic loading. This
reliability shall be achieved by meeting or exceeding the composite reinforcement stress ratio
values given in Table 6.3 of this annex. Stress ratio is defined as the stress in the fibre at the
specified minimum burst pressure divided by the stress in the fibre at working pressure. The
burst ratio is defined as the actual burst pressure of the cylinder divided by the working
pressure; For Type CNG-4 designs, the stress ratio is equal to the burst ratio; For Type CNG-2
and CNG-3 designs (metal-lined, composite over-wrapped) stress ratio calculations must
include:
(a)
(b)
(c)
(d)
(e)
(f)
An analysis method with capability for non-linear materials (special purpose computer
program or finite element analysis program);
Elastic-plastic stress-strain curve for liner material must be known and correctly
modelled;
Mechanical properties of composite materials must be correctly modelled;
Calculations must be made at: auto-frettage, zero after auto-frettage, working and
minimum burst pressures;
Prestresses from winding tension must be accounted for in the analysis;
Minimum burst pressure must be chosen such that the calculated stress at minimum
burst pressure divided by the calculated stress at working pressure meets the stress
ratio requirements for the fibre used;

6.11. Cylinder Supports
The manufacturer shall specify the means by which cylinders shall be supported for installation
on vehicles. The manufacturer shall also supply support installation instructions, including
clamping force and torque to provide the required restraining force but not cause unacceptable
stress in the cylinder or damage to the cylinder surface.
6.12. Exterior Environmental Protection
The exterior of cylinders shall meet the requirements of the environmental test conditions of
Paragraph A.14 (Appendix A). Exterior protection may be provided by using any of the
following:
(a)
(b)
(c)
a surface finish giving adequate protection (e.g. metal sprayed on aluminium, anodising);
or
the use of a suitable fibre and matrix material (e.g. carbon fibre in resin); or
a protective coating (e.g. organic coating, paint) that shall meet the requirements of
Paragraph A.9 (Appendix A).
Any coatings applied to cylinders shall be such that the application process does not adversely
affect the mechanical properties of the cylinder. The coating shall be designed to facilitate
subsequent in service inspection and the manufacturer shall provide guidance on coating
treatment during such inspection to ensure the continued integrity of the cylinder.
Manufacturers are advised that an environmental performance test that evaluates the suitability
of coating systems is provided in the informative Appendix H to this annex.
6.13. Design Qualification Tests
For the approval of each cylinder type the material, design, manufacture and examination shall
be proved to be adequate for their intended service by meeting the appropriate requirements of
the material qualification tests summarised in Table 6.1 of this annex and the cylinder
qualification tests summarised in Table 6.4 of this annex, with all tests in accordance with the
relevant methods of test as described in Appendix A to this annex. The test cylinders or liners
shall be selected and the tests witnessed by the Competent Authority. If more cylinders or
liners are subjected to the tests than are required by this annex, all results shall be
documented.
6.14. Batch Tests
The batch tests specified in this annex for each cylinder type shall be conducted on cylinders or
liners taken from each batch of finished cylinders or liners. Heat treated witness samples
shown to be representative of finished cylinders or liners may also be used. Batch tests
required for each cylinder type are specified in Table 6.5 of this annex.

6.16. Failure to Meet Test Requirements
In the event of failure to meet test requirements retesting or reheat treatment and retesting
shall be carried out as follows:
(a)
(b)
if there is evidence of a fault in carrying out a test, or an error of measurement, a further
test shall be performed. If the result of this test is satisfactory, the first test shall be
ignored;
If the test has been carried out in a satisfactory manner, the cause of test failure shall be
identified.
If the failure is considered to be due to the heat treatment applied, the manufacturer may
subject all the cylinders of the batch to a further heat treatment.
If the failure is not due to the heat treatment applied, all the identified defective cylinders shall
be rejected or repaired by an approved method. The non-rejected cylinders are then
considered as a new batch.
In both cases the new batch shall be retested. All the relevant prototype or batch tests needed
to prove the acceptability of the new batch shall be performed again. If one or more tests prove
even partially unsatisfactory, all cylinders of the batch shall be rejected.
6.17. Change of Design
A design change is any change in the selection of structural materials or dimensional change
not attributable to normal manufacturing tolerances.
Minor design changes shall be permitted to be qualified through a reduced test
program. Changes of design specified in Table 6.7 shall require design qualification testing as
specified in the table.
Table 6.1
Material Design Qualification Test
Relevant paragraph of this annex
Steel
Aluminium
Resins
Fibres
Plastic liners
Tensile properties
6.3.2.2
6.3.3.4
6.3.5
6.3.6
Impact properties
6.3.2.3
Bending properties
6.3.2.4
Weld examination
6.3.2.5
Sulfide stress cracking resistance
6.3.2.6
Sustained load cracking resistance
6.3.3.3
Stress corrosion cracking
6.3.3.2
Shear strength
6.3.4.2
Glass transition temperature
6.3.4.3
Softening/Melting temperature
6.3.6
Fracture mechanics
6.7
6.7
Not required if flawed cylinder test approach in Paragraph A.7 of Appendix A is used.

Test and annex reference
A.12 Burst
A.13 Ambient temp/cycle
A.14 Acid environment test
A.15 Bonfire
A.16 Penetration
A.17 Flaw tolerance
A.18 High temp. creep
A.19 Stress rupture
A.20 Drop test
A.21 Permeation
A.24 PRD performance
A.25 Boss torque test
A.27 Natural gas cylinder
A.6 LBB assessment
A.7 Extreme temperature/cycle
Table 6.4
Cylinder Design Qualification Tests
Cylinder type
CNG−1 CNG−2 CNG−3 CNG−4
X ∗
X ∗
X
X
X
X
X = required
∗ = Not required for cylinders designed to ISO 9809 (ISO 9809 already provides for these tests).
Test and annex reference
A.12 Burst
A.13 Ambient cycle
A.1 Tensile
A.2 Impact (steel)
A.9.2 Coating ∗
Table 6.5
Batch Tests
X
X
X
X
X
X
X
X
X
X
X
Cylinder type
CNG−1 CNG−2 CNG−3 CNG−4
X
X
X
X
X
X = required
∗ = Except where no protective coating is used
† = Tests on liner material
X
X
X †
X †
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X †
X †
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

7. TYPE CNG-1 METAL CYLINDERS
7.1. General
The design shall identify the maximum size of an allowable defect at any point in the cylinder
which will not grow to a critical size within the specified retest period, or service life if no retest
is specified, of a cylinder operating to the working pressure. Determination of
leak-before-break (LBB) performance shall be done in accordance with the appropriate
procedures defined in Paragraph A.6 (Appendix A). Allowable defect size shall be determined
in accordance with Paragraph 6.15.2. above.
Cylinders designed in accordance with ISO 9809 and meeting all the requirements therein are
only required to meet the materials test requirements of Paragraph 6.3.2.4. above and the
design qualification test requirements of Paragraph 7.5., except Paragraphs 7.5.2. and 7.5.3.
below.
7.2. Stress Analysis
The stresses in the cylinder shall be calculated for 2 MPa, 20 MPa, test pressure and design
burst pressure. The calculations shall use suitable analysis techniques using thin-shell theory
that takes into account out-of-plane bending of the shell to establish stress distributions at the
neck, transition regions and the cylindrical part of the cylinder.
7.3. Manufacturing and Production Test Requirements
7.3.1. General
The ends of aluminium cylinders shall not be closed by a forming process. The base ends of
steel cylinders which have been closed by forming, except those cylinders designed in
accordance with ISO 9809, shall be NDE inspected or equivalent. Metal shall not be added in
the process of closure at the end. Each cylinder shall be examined before end forming
operations for thickness and surface finish.
After end forming the cylinders shall be heat treated to the hardness range specified for the
design. Localised heat treatment is not permitted.
When a neck ring, foot ring or attachments for support are provided, it shall be of material
compatible with that of the cylinder and shall be securely attached by a method other than
welding, brazing or soldering.
7.3.2. Non-destructive Examination
The following tests shall be carried out on each metallic cylinder:
(a)
(b)
Hardness test in accordance with Paragraph A.8 (Appendix A),
Ultrasonic examination, in accordance with BS 5045, Part 1, Annex I, or demonstrated
equivalent NDT method, to ensure that the maximum defect size does not exceed the
size specified in the design as determined in accordance with Paragraph 6.15.2. above.
7.3.3. Hydrostatic Pressure Testing
Each finished cylinder shall be hydrostatically pressure tested in accordance with
Paragraph A.11 (Appendix A).

(iv)
(v)
(vi)
should more than 6 months have expired since the last batch of production then a
cylinder from the next batch of production shall be pressure cycle tested in order to
maintain the reduced frequency of batch testing in (ii) or (iii) above.
should any reduced frequency pressure cycle test cylinder in (ii) or (iii) above fail
to meet the required number of pressure cycles (minimum 22,500 or
30,000 pressure cycles, respectively,) then it shall be necessary to repeat the
batch pressure cycle test frequency in (i) for a minimum 10 production batches in
order to re-establish the reduced frequency of batch pressure cycle testing in (ii) or
(iii) above.
should any cylinder in (i), (ii), or (iii) above fail to meet the minimum cycle life
requirement of 1,000 cycles times the specified service life in years (minimum
15,000 cycles), then the cause of failure shall be determined and corrected
following the procedures in Paragraph 6.16. The pressure cycle test shall then be
repeated on an additional three cylinders from that batch. Should any of the three
additional cylinders fail to meet the minimum pressure cycling requirement of
1,000 cycles times the specified service life in years, then the batch shall be
rejected.
7.5. Cylinder Design Qualification Tests
7.5.1. General
Qualification testing shall be conducted on finished cylinders which are representative of
normal production and complete with identification marks. Selection, witnessing and
documentation of the results shall be in accordance with Paragraph 6.13. above.
7.5.2. Hydrostatic Pressure Burst Test
Three representative cylinders shall be hydrostatically pressurised to failure in accordance with
Paragraph A.12. (Appendix A to this annex). The cylinder burst pressures shall exceed the
minimum burst pressure calculated by the stress analysis for the design, and shall be at least
45 MPa.
7.5.3. Ambient Temperature Pressure Cycling Test.
Two finished cylinders shall be pressure cycled at ambient temperature in accordance with
Paragraph A.13 (Appendix A) to failure, or to a minimum of 45,000 cycles. The cylinders shall
not fail before reaching the specified service life in years times 1,000 cycles. Cylinders
exceeding 1,000 cycles times the specified service life in years shall fail by leakage and not by
rupture. Cylinders which do not fail within 45,000 cycles shall be destroyed either by continuing
the cycling until failure occurs, or by hydrostatically pressurising to burst. The number of cycles
to failure and the location of the failure initiation shall be recorded.
7.5.4. Bonfire Test
Tests shall be conducted in accordance with Paragraph A.15 (Appendix A) and meet the
requirements therein.

8.3. Manufacturing Requirements
8.3.1. General
8.3.2. Liner
The composite cylinder shall be fabricated from a liner over-wrapped with continuous filament
windings. Filament winding operations shall be computer or mechanically controlled. The
filaments shall be applied under controlled tension during winding. After winding is complete,
thermosetting resins shall be cured by heating, using a predetermined and controlled
time-temperature profile.
The manufacture of a metallic liner shall meet the requirements given under Paragraph 7.3.
above for the appropriate type of liner construction.
8.3.3. Over-wrap
The cylinders shall be fabricated in a filament winding machine. During winding the significant
variables shall be monitored within specified tolerances, and documented in a winding
record. These variables can include but are not limited to:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
fibre type including sizing;
manner of impregnation;
winding tension;
winding speed;
number of rovings;
band width;
type of resin and composition;
temperature of the resin;
temperature of the liner.
8.3.3.1. Curing of thermosetting resins
If a thermosetting resin is used, the resin shall be cured after filament winding. During the
curing, the curing cycle (i.e. the time-temperature history) shall be documented.
The curing temperature shall be controlled and shall not affect the material properties of the
liner. The maximum curing temperature for cylinders with aluminium liners is 177°C.
8.3.4. Auto-frettage
Auto-frettage, if used, shall be carried out before the hydrostatic pressure test. The
auto-frettage pressure shall be within the limits established in Paragraph 8.2.3. above, and the
manufacturer shall establish the method to verify the appropriate pressure.

Where the coating fails to meet the requirements of Paragraph A.9.2. (Appendix A), the
batch shall be 100% inspected to remove similarly defective cylinders. The coating on
all defective cylinders may be stripped using a method that does not affect the integrity of
the composite wrapping, and recoated. The coating batch test shall then be repeated.
(b)
(c)
Batch burst test. One cylinder shall be tested in accordance with the requirements of
Paragraph 7.4(b) above;
Periodic pressure cycling test. In accordance with the requirements of Paragraph 7.4(c)
above.
8.6. Cylinder Design Qualification Tests
8.6.1. General
Qualification testing shall be conducted on cylinders which are representative of normal
production and complete with identification marks. Selection, witnessing and documentation of
the results shall comply with Paragraph 6.13. above.
8.6.2. Hydrostatic Pressure Burst Test
(a)
One liner shall be hydrostatically burst in accordance with Paragraph A.12.
(Appendix A). The burst pressure shall exceed the minimum burst pressure specified for
the liner design;
(b) Three cylinders shall be hydrostatically burst in accordance with Paragraph A.12
(Appendix A). Cylinder burst pressures shall exceed the specified minimum burst
pressure established by the stress analysis for the design, in accordance with Table 6.3,
and in no case less than the value necessary to meet the stress ratio requirements of
Paragraph 6.5 above.
8.6.3. Ambient Temperature Pressure Cycling Test
Two finished cylinders shall be pressure cycle tested at ambient temperature in accordance
with Paragraph A.13 (Appendix A) to failure, or to a minimum of 45,000 cycles. The cylinders
shall not fail before reaching the specified service life in years times 1,000 cycles. Cylinders
exceeding 1,000 cycles times the specified service life in years shall fail by leakage and not by
rupture. Cylinders which do not fail within 45,000 cycles shall be destroyed either by continuing
the cycling until failure occurs, or by hydrostatically pressurising to burst. Cylinders exceeding
45,000 cycles are permitted to fail by rupture. The number of cycles to failure and the location
of the failure initiation shall be recorded.
8.6.4. Acid Environment Test
One cylinder shall be tested in accordance with Paragraph A.14 (Appendix A) and meet the
requirements therein. An optional environmental test is included in the informative Appendix H
to this annex.
8.6.5. Bonfire Test
Finished cylinders shall be tested in accordance with Paragraph A.15 (Appendix A) and meet
the requirements therein.

9.2.3. Stress Analysis
The stresses in the tangential and longitudinal direction of the cylinder in the composite and in
the liner after pressure shall be calculated. The pressure used for these calculations shall be
zero, working pressure, 10% of working pressure, test pressure and design burst pressure. The
limits within which auto-frettaging pressure must fall shall be calculated, The calculations shall
use suitable analysis techniques using thin-shell theory taking account of non-linear material
behaviour of the liner to establish stress distributions at the neck, transition regions and the
cylindrical part of the liner.
9.3. Manufacturing Requirements
Manufacturing requirements shall be in accordance with Paragraph 8.3. above except that the
over-wrap shall also include helically wound filaments.
9.4. Production Test Requirements
Production test requirements shall be in accordance with the requirements of Paragraph 8.4.
above.
9.5. Cylinder Batch Tests
The batch tests shall be in accordance with the requirements of Paragraph 8.5. above.
9.6. Cylinder Design Qualification Tests
Cylinder design qualification tests shall be in accordance with the requirements of
Paragraph 8.6. above, and Paragraph 9.6.1. below, except that the liner burst in Paragraph 8.6.
above is not required.
9.6.1. Drop Test
One or more finished cylinders shall be drop tested in accordance with Paragraph A.30
(Appendix A).
10. TYPE CNG-4 ALL-COMPOSITE CYLINDERS
10.1. General
This annex does not give a definite method for the design of cylinders with polymeric liners
because of the variety of cylinder designs possible.
10.2. Design Requirements
Design calculations shall be used to provide justification of design adequacy. The tensile
stresses in the fibres shall meet the requirements of Paragraph 6.5. above. Tapered and
straight threads in accordance with Paragraph 6.10.2. or 6.10.3. above shall be used on the
metal end bosses.
Metal end bosses with threaded openings shall be able to withstand a torque force of 500 Nm,
without damaging the integrity of the connection to the non-metallic liner. The metal end
bosses connected to the non-metallic liner shall be of a material compatible with the service
conditions specified in Paragraph 4 of this annex.

(iv)
When a protective coating is a part of the design, the coating shall be tested in
accordance with Paragraph A.9.2 (Appendix A). Where the coating fails to meet
the requirements of Paragraph A.9.2 (Appendix A), the batch shall be 100%
inspected to remove similarly defective cylinders. The coating on all defective
cylinders may be stripped using a method that does not affect the integrity of the
composite wrapping, and recoated. The coating batch test shall then be repeated.
(b)
Batch burst test
One cylinder shall be tested in accordance with the requirements of Paragraph 7.4(b)
above;
(c)
Periodic pressure cycling test
On one cylinder the end boss shall be torque tested to 500 Nm in accordance with the
test method in Paragraph A.25 (Appendix A). The cylinder shall then be pressure cycle
tested in accordance with the procedures provided in Paragraph 7.4(c) above.
Following the required pressure cycling, the cylinder shall be leak tested in accordance
with the method described in Paragraph A.10 (Appendix A) and meet the requirements
therein.
10.7. Cylinder Design Qualification Tests
10.7.1. General
Cylinder design qualification tests shall be in accordance with the requirements of
Paragraphs 8.6., 10.7.2., 10.7.3. and 10.7.4. of this annex, except that the LBB performance in
Paragraph 8.6.10. above is not required.
10.7.2. Boss Torque Test
One cylinder shall be tested in accordance with Paragraph A.25 (Appendix A).
10.7.3. Permeation Test
One cylinder shall be tested for permeation in accordance with Paragraph A.21 (Appendix A)
and meet the requirements therein.
10.7.4. Natural Gas Cycling Test
One finished cylinder shall be tested in accordance with Paragraph A.27 (Appendix A) and
meet the requirements therein.

(b)
Non-mandatory information:
On a separate label(s) the following non-mandatory information may be provided:
(i)
(ii)
(iii)
Gas temperature range, e.g. -40°C to 65°C;
Nominal water capacity of the cylinder to two significant numbers. e.g. 120 litres;
Date of original pressure test (month and year).
The markings shall be placed in the listed sequence but the specific arrangement may
be varied to match the space available. An acceptable example of mandatory
information is:
CNG ONLY
DO NOT USE AFTER . ./. . . .
Manufacturer/Part Number/Serial Number
20 MPa/15°C
ECE R 110 CNG-2 (Registration No.)
"Use Only Manufacturer-Approved Pressure Relief Device"
12. PREPARATION FOR DISPATCH
Prior to dispatch from the manufacturers shop, every cylinder shall be internally clean and
dried. Cylinders not immediately closed by the fitting of a valve, and safety devices if
applicable, shall have plugs, which prevent entry of moisture and protect threads, fitted to all
openings. A corrosion inhibitor (e.g. oil-containing) shall be sprayed into all steel cylinders and
liners prior to dispatch.
The manufacturer's statement of service and all necessary information to ensure the proper
handling, use and in-service inspection of the cylinder shall be supplied to the purchaser. The
statement shall be in accordance with Appendix D to this annex.

A.6.
LEAK-BEFORE-BREAK (LBB) PERFORMANCE TEST
Three finished cylinders shall be pressure cycled between not more than 2 MPa and not less
than 30 MPa at a rate not to exceed 10 cycles per minute.
All cylinders shall fail by leakage.
A.7.
EXTREME TEMPERATURE PRESSURE CYCLING
Finished cylinders, with the composite wrapping free of any protective coating, shall be cycle
tested, without showing evidence of rupture, leakage, or fibre unravelling, as follows:
(a)
(b)
(c)
(d)
Condition for 48 hours at zero pressure, 65°C or higher, and 95% or greater relative
humidity. The intent of this requirement shall be deemed met by spraying with a fine
spray or mist of water in a chamber held at 65°C;
Hydrostatically pressurised for 500 cycles times the specified service life in years
between not more than 2 MPa and not less than 26 MPa at 65° or higher and 95%
humidity;
Stabilise at zero pressure and ambient temperature;
Then pressurise from not more than 2 MPa to not less than 20 MPa for 500 cycles times
the specified service life in years at -40°C or lower;
The pressure cycling rate of b) shall not exceed 10 cycles per minute. The pressure cycling
rate of d) shall not exceed 3 cycles per minute unless a pressure transducer is installed directly
within the cylinder. Adequate recording instrumentation shall be provided to ensure the
minimum temperature of the fluid is maintained during the low temperature cycling.
Following pressure cycling at extreme temperatures, cylinders shall be hydrostatically
pressured to failure in accordance with the hydrostatic burst test requirements, and achieve a
minimum burst pressure of 85% of the minimum design burst pressure. For Type CNG-4
designs, prior to the hydrostatic burst test the cylinder shall be leak tested in accordance with
Paragraph A.10 below.
A.8.
BRINELL HARDNESS TEST
Hardness tests shall be carried out on the parallel wall at the centre and a domed end of each
cylinder or liner in accordance with ISO 6506. The test shall be carried out after the final heat
treatment and the hardness values thus determined shall be in the range specified for the
design.

A.10.
LEAK TEST
Type CNG-4 designs shall be leak tested using the following procedure (or an acceptable
alternative);
(a)
(b)
cylinders shall be thoroughly dried and pressurised to working pressure with dry air or
nitrogen, and containing a detectable gas such as helium;
any leakage measured at any point that exceeds 0.004 standard cm /h shall be cause for
rejection.
A.11.
HYDRAULIC TEST
One of the following two options shall be used:
Option 1: Water Jacket Test
(a)
(b)
(c)
The cylinder shall be hydrostatically tested to at least 1.5 times working pressure. In no
case may the test pressure exceed the auto-frettage pressure;
Pressure shall be maintained for a sufficiently long period (at least 30 seconds) to ensure
complete expansion. Any internal pressure applied after auto-frettage and previous to
the hydrostatic test shall not exceed 90% of the hydrostatic test pressure. If the test
pressure cannot be maintained due to failure of the test apparatus, it is permissible to
repeat the test at a pressure increased by 700 kPa. Not more than 2 such repeat tests
are permitted;
The manufacturer shall define the appropriate limit of permanent volumetric expansion
for the test pressure used, but in no case shall the permanent expansion exceed 5% of
the total volumetric expansion measured under the test pressure. For Type CNG-4
designs, the elastic expansion shall be established by the manufacturer. Any cylinders
not meeting the defined rejection limit shall be rejected and either destroyed or used for
batch test purposes.
Option 2: Proof Pressure Test
The hydrostatic pressure in the cylinder shall be increased gradually and regularly until the test
pressure, at least 1.5 times working pressure, is reached. The cylinder test pressure shall be
held for a sufficiently long period (at least 30 seconds) to ascertain that there is no tendency for
the pressure to decrease and that tightness is guaranteed;
A.12.
HYDROSTATIC PRESSURE BURST TEST
(a)
(b)
The rate of pressurisation shall not exceed 1.4 MPa per second (200 psi/second) at
pressures in excess of 80% of the design burst pressure. If the rate of pressurisation at
pressures in excess of 80% of the design burst pressure exceeds 350 kPa/second
(50 psi/second), then either the cylinder must be placed schematically between the
pressure source and the pressure measurement device, or there must be a 5 second
hold at the minimum design burst pressure;
The minimum required (calculated) burst pressure shall be at least 45 MPa, and in no
case less than the value necessary to meet the stress ratio requirements. Actual burst
pressure shall be recorded. Rupture may occur in either the cylindrical region or the
dome region of the cylinder.

A.15.3.
Fire Source
A uniform fire source of 1.65 m length shall provide direct flame impingement on the cylinder
surface across its entire diameter.
Any fuel may be used for the fire source provided it supplies uniform heat sufficient to maintain
the specified test temperatures until the cylinder is vented. The selection of fuel should take
into consideration air pollution concerns. The arrangement of the fire shall be recorded in
sufficient detail to ensure the rate of heat input to the cylinder is reproducible. Any failure or
inconsistency of the fire source during a test invalidate the result;
A.15.4.
Temperature and Pressure Measurements
Surface temperatures shall be monitored by at least three thermocouples located along the
bottom of the cylinder and spaced not more than 0.75 m apart; Metallic shielding shall be used
to prevent direct flame impingement on the thermocouples. Alternatively, thermocouples may
be inserted into blocks of metal measuring less than 25 mm square.
The pressure inside the cylinder shall be measured by a pressure sensor without modify the
configuration of the system under test.
Thermocouple temperatures and the cylinder pressure shall be recorded at intervals of every
30 seconds or less during the test.
A.15.5.
General Test Requirements
Cylinders shall be pressurised with natural gas and tested in the horizontal position at both:
(a)
(b)
working pressure;
25% of the working pressure.
Immediately following ignition, the fire shall produce flame impingement on the surface of the
cylinder along the 1.65 m length of the fire source and across the cylinder diameter. Within
5 minutes of ignition, at least one thermocouple shall indicate a temperature of at least
590°C. This minimum temperature shall be maintained for the remaining duration of the test.
A.15.6.
Cylinders 1.65 m Length or Less
The centre of the cylinder shall be positioned over the centre of the fire source;
A.15.7.
Cylinders Greater Than 1.65 m Length
If the cylinder is fitted with a pressure relief device at one end, the fire source shall commence
at the opposite end of the cylinder; If the cylinder is fitted with pressure relief devices at both
ends, or at more than one location along the length of the cylinder, the centre of the fire source
shall be centred midway between the pressure relief devices that are separated by the greatest
horizontal distance.
If the cylinder is additionally protected using thermal insulation, then two fire tests at service
pressure shall be performed, one with the fire centred midway along the cylinder length, and
the other with the fire commencing at one of the cylinder ends.

A.20.
IMPACT DAMAGE TEST
One or more finished cylinders shall be drop tested at ambient temperature without internal
pressurisation or attached valves. The surface onto which the cylinders are dropped shall be a
smooth, horizontal concrete pad or flooring. One cylinder shall be dropped in a horizontal
position with the bottom 1.8 m above the surface onto which it is dropped. One cylinder shall
be dropped vertically on each end at a sufficient height above the floor or pad so that the
potential energy is 488 J, but in no case shall the height of the lower end be greater than
1.8 m. One cylinder shall be dropped at a 45° angle onto a dome from a height such that the
centre of gravity is at 1.8 m; however, if the lower end is closer to the ground than 0.6 m, the
drop angle shall be changed to maintain a minimum height of 0.6 m and a centre of gravity of
1.8 m.
Following the drop impact, the cylinders shall be pressure cycled from not more than 2 MPa to
not less than 26 MPa bar for 1,000 cycles times the specified service life in years. The
cylinders may leak but not rupture, during the cycling. Any cylinders completing the cycling test
shall be destroyed;
A.21.
PERMEATION TEST
This test is only required on Type CNG-4 designs. One finished cylinder shall be filled with
compressed natural gas or a 90% nitrogen/10% helium mixture to working pressure, placed in
an enclosed sealed chamber at ambient temperature, and monitored for leakage for a time
sufficient to establish a steady state permeation rate. The permeation rate shall be less than
0.25 ml of natural gas or helium per hour per litre water capacity of the cylinder.
A.22.
TENSILE PROPERTIES OF PLASTICS
The tensile yield strength and ultimate elongation of plastic liner material shall be determined at
-50°C using ISO 3628, and meet the requirements of Paragraph 6.3.6. of Annex 3.
A.23.
MELTING TEMPERATURE OF PLASTICS
Polymeric materials from finished liners shall be tested in accordance with the method
described in ISO 306, and meet the requirements of Paragraph 6.3.6. of Annex 3.

A.27.
NATURAL GAS CYCLING TEST
One finished cylinder shall be pressure cycled using compressed natural gas from less than
2 MPa to working pressure for 300 cycles. Each cycle, consisting of the filling and venting of
the cylinder, shall not exceed 1 hour. The cylinder shall be leak tested in accordance with
Paragraph A.10 above and meet the requirements therein. Following the completion of the
natural gas cycling the cylinder shall be sectioned and the liner/end boss interface inspected for
evidence of any deterioration, such as fatigue cracking or electrostatic discharge.
NOTE - Special consideration must be given to safety when conducting this test. Prior to
conducting this test, cylinders of this design must have successfully passed the test
requirements of Paragraph A.12 above (hydrostatic pressure burst test), Paragraph 8.6.3 of
Annex 3 (ambient temperature pressure cycling test) and Paragraph A.21 above (permeation
test). Prior to conducting this test, the specific cylinders to be tested must pass the test
requirements of Paragraph A.10 above (leak test).
A.28.
A.29.
Deleted by Supplement 8 (Rev.1/Add.16/Rev.4/Amend.2)
BEND TEST, WELDED STAINLESS STEEL LINERS
Bend tests shall be carried out on material taken from the cylindrical part of a welded
stainless steel liner and tested in accordance with the method described in Paragraph 8.5. of
EN 13322-2. The test piece shall not crack when bent inwards around a former until the inside
edges are not further apart than the diameter of the former.
APPENDIX B – NOT ALLOCATED
APPENDIX C – NOT ALLOCATED

FORM 1
REPORT OF MANUFACTURER AND CERTIFICATION OF CONFORMANCE
Manufactured by:
Located at:
Regulatory Registration Number:
Manufacturers Mark and Number:
Serial Number: from ....................................................
to ......................................................... inclusive
Cylinder description:
SIZE: Outside diameter: ......................................... mm; Length: ....................................................... mm;
Marks stamped on shoulder or on labels of the cylinder are:
(a)
"CNG ONLY": .......................................................................................................................................
(b)
"DO NOT USE AFTER":.......................................................................................................................
(c)
Manufacturer's mark:............................................................................................................................
(d)
Serial and part number:........................................................................................................................
(e)
Working pressure in MPa:....................................................................................................................
(f)
ECE Regulation:...................................................................................................................................
(g)
Fire protection type:..............................................................................................................................
(h)
Date of original test (month & year): ....................................................................................................
(i)
Tare mass of empty cylinder (in kg): ....................................................................................................
(j)
Authorised Body or Inspectors Mark: ...................................................................................................
(k)
Water capacity in L:..............................................................................................................................
(l)
Test pressure in MPa: ..........................................................................................................................
(m)
Any special instructions:.......................................................................................................................
Each cylinder was made in compliance with all requirements of ECE Regulation No. ... in accordance
with the cylinder description above. Required reports of test results are attached.
I hereby certify that all these test results proved satisfactory in every way and are in compliance with the
requirements for the type listed above.
Comments : ....................................................................................................................................................
Competent Authority:......................................................................................................................................
Inspector’s signature: .....................................................................................................................................
Manufacturer's signature: ...............................................................................................................................
Place, Date: ....................................................................................................................................................

APPENDIX F
FRACTURE PERFORMANCE METHODS
F.1.
DETERMINATION OF FATIGUE SENSITIVE SITES
The location and orientation of fatigue failure in cylinders shall be determined by appropriate
stress analysis or by full scale fatigue tests on finished cylinders as required under the design
qualification tests for each type of design. If finite element stress analysis is used, the fatigue
sensitive site shall be identified based on the location and orientation of the highest tensile
principal stress concentration in the cylinder wall or liner at the working pressure.
F.2.
F.2.1.
LEAK-BEFORE-BREAK (LBB)
Engineering critical assessment This analysis may be carried out to establish that the finished
cylinder will leak in the event of a defect in the cylinder or liner growing into a through-wall
crack. A leak-before-break assessment shall be performed at the cylinder side wall. If the
fatigue sensitive location is outside the side wall, a leak-before-break assessment shall also be
performed at that location using a Level II approach as outlined in BS PD6493. The
assessment shall include the following steps:
(a)
(b)
(c)
(d)
(e)
Measure the maximum length (i.e. major axis) of the resultant through-wall surface crack
(usually elliptical in shape) from the three cylinder cycle tested under the design
qualification tests (according to Paragraphs A.13 and A.14 of Appendix A) for each type
of design. Use the longest crack length of the three cylinders in the analysis. Model a
semi-elliptical through-wall crack with a major axis equal to twice the measured longest
major axis and with a minor axis equal to 0.9 of wall thickness. The semi-elliptical crack
shall be modelled at the locations specified in Paragraph F.1. of Appendix F. The crack
shall be oriented such that the highest tensile principal stress shall drive the crack;
Stress levels in the wall/liner at 26 MPa obtained from the stress analysis as outlined in
Paragraph 6.6 of Annex 3 shall be used for the assessment. Appropriate crack driving
forces shall be calculated using either Section 9.2 or 9.3 of BS PD6493;
Fracture toughness of the finished cylinder or the liner from a finished cylinder, as
determined at room temperature for aluminium and at -40°C for steel, shall be
established using a standardised testing technique (either ISO/DIS 12737 or
ASTM 813-89 or BS 7448) in accordance with Sections 8.4 and 8.5 of BS PD6493;
Plastic collapse ratio shall be calculated in accordance with Section 9.4 of
BS PD6493-91;
The modelled flaw shall be acceptable in accordance with Section 11.2 of
BS PD6493-91.

(d)
Acceptance criteria for the flawed cylinder test
The cylinder passes the tests if the following conditions are met:
(i)
For monotonic pressurisation burst test, the failed pressure shall be equal or
greater than 26 MPa;
For monotonic pressurised burst test, a total crack length measured on the
external surface of 1.1 times the original machined length is allowed.
(ii)
For cycle tested cylinders, fatigue crack growth beyond the original machined flaw
length is allowed. However, the failure mode must be a "leak". Propagation of the
flaw by fatigue should occur over at least 90% of the length of the original
machined flaw;
NOTE - If these requirements are not fulfilled (failure occurs below 36 MPa, even and if
the failure is a leak), a new test can be performed with a less deep flaw. Also, if rupture
type failure occurs at a pressure greater than 26 MPa and flaw depth is shallow, a new
test can be performed with a deeper flaw.
F.3.
F.3.1.
DEFECT SIZE FOR NON-DESTRUCTIVE EXAMINATION (NDE)
NDE Defect Size by Engineering Critical Assessment
Calculations shall be performed in accordance with British Standard (BS) PD 6493, Section 3,
using the following steps:
(a)
(b)
(c)
Fatigue cracks shall be modelled at the high stress location in the wall/liner as planar
flaws;
The applied stress range at the fatigue sensitive site, due to a pressure between 2 MPa
and 20 MPa, shall be established from the stress analysis as outlined in Paragraph F.1.
of Appendix F;
The bending and membrane stress component may be used separately;
(d) The minimum number of pressure cycles is 15,000;
(e)
(f)
The fatigue crack propagation data shall be determined in air in accordance with
ASTM E647. The crack plane orientation shall be in the C-L direction (i.e., crack plane
perpendicular to the circumferences and along the axis of the cylinder), as illustrated in
ASTM E399. The rate shall be determined as an average of 3 specimen tests. Where
specific fatigue crack propagation data are available for the material and service
condition, they may be used in the assessment.
The amount of crack growth in the thickness direction and in the length direction per
pressures cycle shall be determined in accordance with the steps outlined in
Section 14.2 of the BS PD 6493-91 standard by integrating the relationship between the
rate of fatigue crack propagation, as established in (e) above, and the range of crack
driving force corresponding to the applied pressure cycle;

APPENDIX G
INSTRUCTIONS BY THE CONTAINER MANUFACTURER REGARDING
HANDLING, USE AND INSPECTION OF CYLINDERS
G.1.
GENERAL
The primary function of this appendix is to provide guidance to the cylinder purchaser,
distributor, installer and user for the safe use of the cylinder over its intended service life.
G.2.
DISTRIBUTION
The manufacturer shall advise the purchaser that the instructions shall be supplied to all parties
involved in the distribution, handling, installation and use of the cylinders; The document may
be reproduced to provide sufficient copies for this purpose, however it shall be marked to
provide reference to the cylinders being delivered;
G.3.
REFERENCE TO EXISTING CODES, STANDARDS AND REGULATIONS
Specific instructions may be stated by reference to national or recognised codes, standards
and regulations.
G.4.
CYLINDER HANDLING
Handling procedures shall be provided to ensure that the cylinders will not suffer unacceptable
damage or contamination during handling.
G.5.
INSTALLATION
Installation instructions shall be provided to ensure that the cylinders will not suffer
unacceptable damage during installation and during normal operation over the intended service
life.
Where the mounting is specified by the manufacturer, the instructions shall contain where
relevant, details such as mounting design, the use of resilient gasket materials, the correct
tightening torques and avoidance of direct exposure of the cylinder to an environment of
chemical and mechanical contacts.
Where the mounting is not specified by the manufacturer, the manufacturer shall draw the
purchaser's attention to possible long term impacts of the vehicle mounting system, for
example: vehicle body movements and cylinder expansion/contraction in the pressure and
temperature conditions of service.
Where applicable, the purchaser's attention shall be drawn to the need to provide installations
such that liquids or solids cannot be collected to cause cylinder material damage;
The correct pressure relieve device to be fitted shall be specified.
G.6.
USE OF CYLINDERS
The manufacturer shall draw the purchaser's attention to the intended service conditions
specified by this Regulation, in particular the cylinder's allowable number of pressure
cycles. Its life in years, the gas quality limits and the allowable maximum pressures.

APPENDIX H
ENVIRONMENTAL TEST
H.1.
SCOPE
The environmental test is intended to demonstrate that NGV cylinders can withstand exposure
to the automotive underbody environment and occasional exposure to other fluids. This test
was developed by the US automotive industry in response to cylinder failures initiated by stress
corrosion cracking of the composite wrap.
H.2.
SUMMARY OF TEST METHOD
A cylinder is first preconditioned by a combination of pendulum and gravel impacts to simulate
potential underbody conditions. The cylinder is then subjected to a sequence of immersion in
simulated road salt/acid rain, exposure to other fluids, pressure cycles and high and low
temperature exposures. At the conclusion of the test sequence the cylinder will be
hydraulically pressured to destruction. The remaining residual burst strength of the cylinder
shall be not less than 85% of the minimum design burst strength.
H.3.
CYLINDER SET-UP AND PREPARATION
The cylinder shall be tested in a condition representative of installed geometry including coating
(if applicable), brackets and gaskets, and pressure fittings using the same sealing configuration
(i.e. O-rings) as that used in service. Brackets may be painted or coated prior to installation in
the immersion test if they are painted or coated prior to vehicle installation.
Cylinders will be tested horizontally and nominally divided along their horizontal centreline into
"upper" and "lower" sections. The lower section of the cylinder will be alternatively immersed in
road salt/acid rain environment and in heated or cooled air.
The upper section will be divided into 5 distinct areas and marked for preconditioning and fluid
exposure. The areas will be nominally 100 mm in diameter. The areas shall not overlap on the
cylinder surface. While convenient for testing, the areas need not be oriented along a single
line, but must not overlap the immersed section of the cylinder.
Although preconditioning and fluid exposure is performed on the cylindrical section of the
cylinder, all of the cylinder, including the domed sections, should be as resistant to the
exposure environments as are the exposed areas.

Figure H.2
Gravel Impact Test
H.5.
EXPOSURE ENVIRONMENTS
(a)
Immersion environment
At the specified stage in the test sequence (Table 1) the cylinder will be oriented
horizontally with the lower third of the cylinder diameter immersed in a simulated acid
rain/road salt water solution. The solution will consist of the following compounds:
Deionised water;
Sodium chloride: 2.5% by weight ± 0.1%;
Calcium chloride: 2.5% by weight ± 0.1%;
Sulfuric acid: Sufficient to achieve a solution pH of 4.0 ± 0.2;
Solution level and pH are to be adjusted prior to each test step which uses this liquid.
The temperature of the bath shall be 21 ± 5°C. During immersion, the unsubmerged
section of the cylinder shall be in ambient air.

H.7.
TEST PROCEDURE
(a)
Preconditioning of the cylinder
Each of the five areas marked for other fluid exposure on the upper section of the
cylinder shall be preconditioned by a single impact of the pendulum body summit at their
geometric centre. Following impact, the five areas shall be further conditioned by a
gravel impact application.
The central section of the bottom portion of the cylinder that will be submerged shall be
preconditioned by an impact of the pendulum body summit at three locations spaced
approximately 150 mm apart.
Following impact, the same central section that was impacted shall be further
conditioned by a gravel impact application.
The cylinder shall be unpressured during preconditioning.
(b)
Test sequence and cycles
The sequence of the environment exposure, pressure cycles, and temperature to be
used are defined in Table 1.
The cylinder surface is not to be washed or wiped between stages.
H.8.
ACCEPTABLE RESULTS
Following the above test sequence, the cylinder shall be hydraulically tested to destruction in
accordance with the procedure in Paragraph A.12. The burst pressure of the cylinder shall be
not less than 85% of the minimum design burst pressure.
Test steps
Table H.1
Test Conditions and Sequence
Exposure
environments
Number of pressure
cycles
Temperature
1
Other fluids

Ambient
2
Immersion
1875
Ambient
3
Air
1875
High
4
Other fluids

Ambient
5
Immersion
1875
Ambient
6
Air
3750
Low
7
Other fluids

Ambient
8
Immersion
1875
Ambient
9
Air
1875
High
10
Other fluids

Ambient
11
Immersion
1875
Ambient

3.2.3. The non-return valve, being in the normal position of use specified by the manufacturer, is
submitted to 20,000 operations; then it is deactivated. The non-return valve shall remain
leak-proof (external) at a pressure of 1.5 times the working pressure (MPa) (see Annex 5B).
3.2.4. The non-return valve shall be so designed to operate at temperatures as specified in
Annex 5O.
3.3. The non-return valve has to comply with the test procedures for the Class component
determined according to the scheme in Figure 1-1 of Paragraph 2 of this Regulation.
4. THE PRESSURE RELIEF VALVE AND PRESSURE RELIEF DEVICE
4.1. The materials constituting the pressure relief valve and pressure relief device which are in
contact with the CNG when operating, shall be compatible with the test CNG. In order to verify
this compatibility, the procedure described in Annex 5D shall be used.
4.2. Operating Specifications
4.2.1. The pressure relief valve and pressure relief device in Class 0 shall be so designed as to
withstand a pressure of 1.5 times the working pressure (MPa).
4.2.2. The pressure relief valve and pressure relief device of Class 1 shall be so designed as to be
leak-proof at a pressure of 1.5 times the working pressure (MPa) with the outlet closed off (see
Annex 5B).
4.2.3. The pressure relief valve of Class 1 and Class 2 shall be so designed as to be leak-proof at
twice the working pressure with the outlets closed off.
4.2.4. The pressure relief device shall be so designed to open the fuse at a temperature of
110 ± 10°C.
4.2.5. The pressure relief valve of Class 0 shall be so designed to operate at temperatures from
-40°C to 85°C.
4.3. The pressure relief valve and pressure relief device have to comply with the test procedures for
the Class component determined according to the scheme in Figure 1-1 of Paragraph 2 of this
Regulation.
5. THE EXCESS FLOW VALVE
5.1. The materials constituting the excess flow valve which are in contact with the CNG when
operating, shall be compatible with the test CNG. In order to verify this compatibility, the
procedure described in Annex 5D shall be used.
5.2. Operating Specifications
5.2.1. The excess flow valve, if it is not integrated in the cylinder, shall be so designed as to withstand
a pressure of 1.5 times the working pressure (MPa).
5.2.2. The excess flow valve shall be so designed as to be leak-proof at a pressure of 1.5 times the
working pressure (MPa).

7.4. PRD (Pressure Triggered) Requirements
7.4.1. Continued Operation
7.4.1.1. Test Procedure
Cycle the PRD (pressure triggered) according to Table 3, with water between 10% and 100%
of the working pressure, at a maximum cyclic rate of 10 cycles per minute and a temperature
of 82° C ± 2° C or 57° C ± 2° C.
Table 3
Test Temperatures and Cycles
Temperature [°C]
Cycles
82 2,000
57 18,000
7.4.1.2. Requirements
7.4.1.2.1. At the completion of the test, the component shall not leak more than 15 cm /hour when
submitted to a gas pressure equal to the maximum working pressure at ambient temperature
and at the maximum operating temperature as indicated in Annex 5O.
7.4.1.2.2. At the completion of the test, the PRD (pressure triggered) burst pressure shall be
34 MPa ± 10% at ambient temperature and at the maximum operating temperature as
indicated in Annex 5O.
7.4.2. Corrosion Resistance Test
7.4.2.1. Test Procedure
The PRD (pressure triggered) shall be subjected to the test procedure described in Annex 5E,
except the leakage test.
7.4.2.2. Requirements
7.4.2.2.1. At the completion of the test, the component shall not leak more than 15 cm /hour when
submitted to a gas pressure equal to the maximum working pressure at ambient temperature
and at the maximum operating temperature as indicated in Annex 5O.
7.4.2.2.2. At the completion of the test, the PRD (pressure triggered) burst pressure shall be
34 MPa ± 10% at ambient temperature and at the maximum operating temperature as
indicated in Annex 5O.

1.3. Specifications and Tests for the Lining
1.3.1. Tensile strength and elongation for rubber material and for thermoplastic elastomers (TPE)
1.3.1.1. Tensile strength and elongation at break according to ISO 37. Tensile strength not less
than 20 MPa and elongation at break not less than 250%.
1.3.1.2. Resistance to n-pentane according to ISO 1817 with the following conditions:
(a)
medium: n-pentane
(b) temperature: 23°C (tolerance according to ISO 1817)
(c)
immersion period: 72 hours
Requirements:
(a) maximum change in volume 20%
(b) maximum change in tensile strength 25%
(c) maximum change in elongation at break 30%
After storage in air with a temperature of 40°C for a period of 48 hours the mass compared to
the original value may not decrease more than 5%.
1.3.1.3. Resistance to ageing according to ISO 188 with the following conditions:
(a)
(b)
temperature: 115°C (test temperature = maximum operating temperature -10°C)
exposure period: 24 and 336 hours
After ageing the specimens have to be conditioned at 23°C and 50% relative humidity for at
least 21 days prior to carrying out the tensile test according to Paragraph 1.3.1.1.
Requirements:
(a)
(b)
maximum change in tensile strength 35% after 336 hours ageing compared to the tensile
strength of the 24 hours aged material.
maximum change in elongation at break 25% after 336 hours ageing compared to the
elongation at break of the 24 hours aged material.

1.4. Specifications and Test-method for the Cover
1.4.1. Tensile strength and elongation for rubber material and for thermoplastic elastomers (TPE)
1.4.1.1. Tensile strength and elongation at break according to ISO 37. Tensile strength not less
than 10 MPa and elongation at break not less than 250%.
1.4.1.2. Resistance to n-hexane according to ISO 1817 with the following conditions:
(a)
medium: n-hexane
(b) temperature: 23°C (tolerance according to ISO 1817)
(c)
immersion period: 72 hours
Requirements:
(a) maximum change in volume 30%
(b) maximum change in tensile strength 35%
(c) maximum change in elongation at break 35%
1.4.1.3. Resistance to ageing according to ISO 188 with the following conditions:
(a)
(b)
temperature: 115°C (test temperature = maximum operating temperature -10°C)
exposure period: 24 and 336 hours
After ageing the specimens have to be conditioned at 23°C and 50% relative humidity for at
least 21 days prior to carrying out the tensile test according to Paragraph 1.4.1.1.
Requirements:
(a)
(b)
maximum change in tensile strength 35% after 336 hours ageing compared to the tensile
strength of the 24 hours aged material.
maximum change in elongation at break 25% after 336 hours ageing compared to the
elongation at break of the 24 hours aged material.

1.4.3. Resistance to Ozone
1.4.3.1. The test has to be performed in compliance with Standard ISO 1431/1.
1.4.3.2. The test-pieces, which have to be stretched to an elongation of 20% shall have to be exposed
to air of 40°C with an ozone-concentration of 50 parts per hundred million during 120 hours.
1.4.3.3. No cracking of the test pieces is allowed.
1.5. Specifications for Uncoupled Hose
1.5.1. Gas-tightness (Permeability)
1.5.1.1. A hose at a free length of 1 m has to be connected to a container filled with liquid propane,
having a temperature of 23° ± 2°C.
1.5.1.2. The test has to be carried out in compliance with the method described in Standard ISO 4080.
1.5.1.3. The leakage through the wall of the hose shall not exceed 95 cm per metre of hose per 24 h.
1.5.2. Resistance at Low Temperature
1.5.2.1. The test has to be carried out in compliance with the method described in
Standard ISO 4672-1978, Method B.
1.5.2.2. Test-temperature: -40° C ± 3° C
or -20° C ± 3° C, if applicable.
1.5.2.3. No cracking or rupture is allowed.
1.5.3. Bending Test
1.5.3.1. An empty hose, at a length of approximately 3.5 m must be able to withstand 3,000 times the
hereafter prescribed alternating-bending-test without breaking. After the test the hose must be
capable of withstanding the test-pressure as mentioned in Paragraph 1.5.4.2. The test shall be
performed on both new hose and after ageing according to ISO 188 as prescribed in
Paragraph 1.4.2.3. and subsequently to ISO 1817 as prescribed in Paragraph 1.4.2.2.

1.5.3.4. The hose shall be S-shape-like installed over the wheels (see Figure 1).
The end, that runs over the upper wheel shall be furnished with a sufficient mass as to achieve
a complete snuggling of the hose against the wheels. The part that runs over the lower wheel
is attached to the propulsion-mechanism.
The mechanism must be so adjusted, that the hose travels a total distance of 1.2 m in both
directions.
1.5.4. Hydraulic-Test-Pressure and Appointment of the Minimum Burst-pressure
1.5.4.1. The test has to be carried out in compliance with the method described in Standard ISO 1402.
1.5.4.2. The test-pressure of 1.5 times the working pressure (MPa) shall be applied during 10 minutes,
without any leakage.
1.5.4.3. The burst pressure shall not be less than 45 MPa.
1.6. Couplings
1.6.1. The couplings shall be made from steel or brass and the surface must be corrosion-resistant.
1.6.2. The couplings must be of the crimp-fitting type.
1.6.2.1. The swivel-nut must be provided with U.N.F.-thread.
1.6.2.2. The sealing cone of swivel-nut type must be of the type with a half vertical angle of 45°.
1.6.2.3. The couplings can be made as swivel-nut type or as quick-connector type.
1.6.2.4. It shall be impossible to disconnect the quick-connector type without specific measures or the
use of dedicated tools.
1.7. Assembly of Hose and Couplings
1.7.1. The construction of the couplings must be such, that it is not necessary to peel the cover
unless the reinforcement of the hose consists of corrosion-resistant material.
1.7.2. The hose assembly has to be subjected to an impulse test in compliance with
Standard ISO 1436.
1.7.2.1. The test has to be completed with circulating oil having a temperature of 93°C, and a minimum
pressure of 26 MPa.
1.7.2.2. The hose has to be subjected to 150,000 impulses.
1.7.2.3. After the impulse-test the hose has to withstand the test-pressure as mentioned in
Paragraph 1.5.4.2.
1.7.3. Gas-tightness
1.7.3.1. The hose assembly (hose with couplings) has to withstand during five minutes a gas pressure
of 1.5 times the working pressure (MPa) without any leakage.

2.3.1.2. Resistance to n-pentane according to ISO 1817 with the following conditions:
(a)
medium: n-pentane
(b) temperature: 23°C (tolerance according to ISO 1817)
(c)
immersion period: 72 hours
Requirements:
(a) maximum change in volume 20%
(b) maximum change in tensile strength 25%
(c) maximum change in elongation at break 30%
After storage in air with a temperature of 40°C for a period of 48 hours the mass compared to
the original value may not decrease more than 5%.
2.3.1.3. Resistance to ageing according to ISO 188 with the following conditions:
(a)
(b)
temperature: 115°C (test temperature = maximum operating temperature -10°C)
exposure period: 24 and 336 hours
After ageing the specimens have to be conditioned at 23°C and 50% relative humidity for at
least 21 days prior to carrying out the tensile test according to Paragraph 2.3.1.1.
Requirements:
(a)
(b)
maximum change in tensile strength 35% after 336 hours ageing compared to the tensile
strength of the 24 hours aged material.
maximum change in elongation at break 25% after 336 hours ageing compared to the
elongation at break of the 24 hours aged material.
2.3.2. Tensile strength and elongation specific for thermoplastic material.
2.3.2.1. Tensile strength and elongation at break according to ISO 527-2 with the following conditions:
(a)
(b)
specimen type: Type 1 BA.
tensile speed: 20 mm/min.
The material has to be conditioned for at least 21 days at 23°C and 50% relative humidity prior
to testing.
Requirement:
(a)
tensile strength not less than 20 MPa.
(b) elongation at break not less than 100%.

Requirements:
(a) maximum change in volume 30%
(b) maximum change in tensile strength 35%
(c) maximum change in elongation at break 35%
2.4.1.3. Resistance to ageing according to ISO 188 with the following conditions:
(a)
(b)
temperature: 115°C (test temperature = maximum operating temperature -10°C)
exposure period: 24 and 336 hours
After ageing the specimens have to be conditioned at 23°C and 50% relative humidity for at
least 21 days prior to carrying out the tensile test according to Paragraph 2.4.1.1.
Requirements:
(a)
(b)
maximum change in tensile strength 35% after 336 hours ageing compared to the tensile
strength of the 24 hours aged material.
maximum change in elongation at break 25% after 336 hours ageing compared to the
elongation at break of the 24 hours aged material.
2.4.2. Tensile strength and elongation specific for thermoplastic material.
2.4.2.1. Tensile strength and elongation at break according to ISO 527-2 with the following conditions:
(a)
(b)
specimen type: Type 1 BA.
tensile speed: 20 mm/min.
The material has to be conditioned for at least 21 days at 23°C and 50% relative humidity prior
to testing.
Requirements:
(a)
tensile strength not less than 20 MPa.
(b) elongation at break not less than 100%.
2.4.2.2. Resistance to n-hexane according to ISO 1817 with the following conditions:
(a)
medium: n-hexane.
(b) temperature: 23°C (tolerance according to ISO 1817).
(c)
immersion period: 72 hours.

2.5.2. Resistance at Low Temperature
2.5.2.1. The test has to be carried out in compliance with the method described in
Standard ISO 4672-1978, Method B.
2.5.2.2. Test-temperature: -40° C ± 3°C
or -20° C ± 3° C, if applicable.
2.5.2.3. No cracking or rupture is allowed.
2.5.3. Bending Test
2.5.3.1. An empty hose, at a length of approximately 3.5 m must be able to withstand 3,000 times the
hereafter prescribed alternating-bending-test without breaking. After the test the hose must be
capable of withstanding the test-pressure as mentioned in Paragraph 2.5.4.2. The test shall be
performed on both new hose and after ageing according to ISO 188 as prescribed in
Paragraph 2.4.2.3. and subsequently to ISO 1817 as prescribed in Paragraph 2.4.2.2.
2.5.3.2.
Hose inside diameter
[mm]
Bending radius
[mm]
(Figure 2)
Figure 2
(Example Only)
Distance between centres [mm]
(Figure 2)
Vertical
b
Horizontal
a
up to 13 102 241 102
13 to 16 153 356 153
from 16 to 20 178 419 178

2.7.2.2. The hose has to be subjected to 150,000 impulses.
2.7.2.3. After the impulse-test the hose has to withstand the test-pressure as mentioned in
Paragraph 2.5.4.2.
2.7.3. Gas-tightness
2.7.3.1. The hose assembly (hose with couplings) has to withstand during five minutes a gas pressure
of 3 MPa without any leakage.
2.8. Markings
2.8.1. Every hose must bear, at intervals of not greater than 0.5 m, the following clearly legible and
indelible identification markings consisting of characters, figures or symbols.
2.8.1.1. The trade name or mark of the manufacturer.
2.8.1.2. The year and month of fabrication.
2.8.1.3. The size and type marking.
2.8.1.4. The identification-marking "C.N.G. Class 1".
2.8.2. Every coupling shall bear the trade name or mark of the assembling manufacturer.
3. LOW PRESSURE HOSES, CLASS 2 CLASSIFICATION
3.1. General specifications
3.1.1. The hose shall be so designed as to withstand a maximum working pressure of 450 kPa.
3.1.2. The hose shall be so designed as to withstand temperatures as specified in Annex 5O.
3.1.3. The inside diameter shall be in compliance with Table 1 of Standard ISO 1307.
3.2. (Not Allocated)
3.3. Specifications and Tests for the Lining
3.3.1. Tensile strength and elongation for rubber material and for thermoplastic elastomers (TPE)
3.3.1.1. Tensile strength and elongation at break according to ISO 37
Tensile strength not less than 10 MPa and elongation at break not less than 250%.

3.3.2.2. Resistance to n-pentane according to ISO 1817 with the following conditions:
(a)
medium: n-pentane.
(b) temperature: 23°C (tolerance according to ISO 1817).
(c)
immersion period: 72 hours.
Requirements:
(a) maximum change in volume 2%.
(b) maximum change in tensile strength 10%.
(c) maximum change in elongation at break 10%.
After storage in air with a temperature of 40°C for a period of 48 hours the mass compared to
the original value may not decrease more than 5%.
3.3.2.3. Resistance to ageing according to ISO 188 with the following conditions:
(a)
(b)
temperature: 115°C (test temperature = maximum operating temperature -10°C).
exposure period: 24 and 336 hours.
After ageing the specimens have to be conditioned at 23°C and 50% relative humidity for at
least 21 days prior to carrying out the tensile test according to Paragraph 3.3.2.1.
Requirements:
(a)
(b)
maximum change in tensile strength 35% after 336 hours ageing compared to the tensile
strength of the 24 hours aged material.
maximum change in elongation at break 25% after 336 hours ageing compared to the
elongation at break of the 24 hours aged material.
3.4. Specifications and Test-Method for the Cover
3.4.1. Tensile strength and elongation for rubber material and for thermoplastic elastomers (TPE)
3.4.1.1. Tensile strength and elongation at break according to ISO 37
Tensile strength not less than 10 MPa and elongation at break not less than 250%.

3.4.2.2. Resistance to n-hexane according to ISO 1817 with the following conditions:
(a)
medium: n-hexane.
(b) temperature: 23°C (tolerance according to ISO 1817).
(c)
immersion period: 72 hours.
Requirements:
(a) maximum change in volume 2%.
(b) maximum change in tensile strength 10%.
(c) maximum change in elongation at break 10%.
After storage in air with a temperature of 40°C for a period of 48 hours the mass compared to
the original value may not decrease more than 5%.
3.4.2.3. Resistance to ageing according to ISO 188 with the following conditions:
(a)
(b)
temperature: 115°C (test temperature = maximum operating temperature -10°C).
exposure period: 24 and 336 hours.
After ageing the specimens have to be conditioned at 23°C and 50% relative humidity for at
least 21 days prior to carrying out the tensile test according to Paragraph 3.4.2.1.
Requirements:
(a)
(b)
maximum change in tensile strength 20% after 336 hours ageing compared to the tensile
strength of the 24 hours aged material.
maximum change in elongation at break 50% after 336 hours ageing compared to the
elongation at break of the 24 hours aged material.
3.4.3. Resistance to Ozone
3.4.3.1. The test has to be performed in compliance with Standard ISO 1431/1.
3.4.3.2. The test-pieces, which have to be stretched to an elongation of 20% shall have to be exposed
to air of 40°C and a relative humidity of 50% ± 10% with an ozone concentration of 50 parts per
hundred million during 120 hours.
3.4.3.3. No cracking of the test pieces is allowed.

3.5.4. Bending Test
3.5.4.1. An empty hose, at a length of approximately 3.5 m must be able to withstand 3,000 times the
hereafter prescribed alternating-bending-test without breaking.
3.5.4.2.
Figure 3
(Example Only)
The testing machine (Figure 3) shall consist of a steel frame, provided with two wooden
wheels, with a rim width of approx. 130 mm.
The circumference of the wheels must be grooved for the guidance of the hose.
The radius of the wheels, measured to the bottom of the groove, must be 102 mm.
The longitudinal median planes of both wheels must be in the same vertical plane. The
distance between the wheel-centres must be vertical 241 mm and horizontal 102 mm.
Each wheel must be able to rotate freely round its pivot-centre.
A propulsion-mechanism pulls the hose over the wheels at a speed of four complete motions
per minute.
3.5.4.3. The hose shall be S-shape-like installed over the wheels (see Figure 3).
The end, that runs over the upper wheel, shall be furnished with a sufficient mass as to achieve
a complete snuggling of the hose against the wheels. The part that runs over the lower wheel
is attached to the propulsion mechanism.
The mechanism must be so adjusted, that the hose travels a total distance of 1.2 m in both
directions.

ANNEX 4C
PROVISIONS REGARDING THE APPROVAL OF THE CNG FILTER
1. The purpose of this annex is to determine the provisions regarding the approval of the CNG
filter.
2. OPERATING CONDITIONS
2.1. The CNG filter shall be so designed to operate at temperatures as specified in Annex 5O.
2.2. CNG filter shall be Classified with regard to the maximum working pressure (see Paragraph 2
of this Regulation):
2.2.1. Class 0: The CNG filter shall be so designed to withstand a pressure of 1.5 times the working
pressure (MPa).
2.2.2. Class 1 and Class 2: The CNG filter shall be so designed to withstand a pressure twice the
working pressure.
2.2.3. Class 3: the CNG filter shall be so designed to withstand a pressure twice the relief pressure of
the pressure relief valve on which it is subject.
2.3. The materials used in the CNG filter which are in contact with CNG when operating, shall be
compatible with this gas (see Annex 5D).
2.4. The component has to comply with the test procedures for class components according to the
scheme in Figure 1-1 of Paragraph 2 of this Regulation.

3. CLASSIFICATION AND TEST PRESSURES
3.1. The part of the pressure regulator which is in contact with the pressure of the container is
regarded as Class 0.
3.1.1. The Class 0 part of the pressure regulator shall be leak-proof (see Annex 5B) at a pressure up
to 1.5 times the working pressure (MPa) with the outlet(s) of that part closed off.
3.1.2. The Class 0 part of the pressure regulator shall withstand a pressure up to 1.5 times the
working pressure (MPa).
3.1.3. The Class 1 and Class 2 part of the pressure regulator shall be leak-proof (see Annex 5B) at a
pressure up to twice the working pressure.
3.1.4. The Class 1 and Class 2 part of the pressure regulator shall withstand a pressure up to twice
the working pressure.
3.1.5. The Class 3 part of the pressure regulator shall withstand a pressure up to twice the relief
pressure of the pressure relief valve, on which it is subject.
3.2. The pressure regulator shall be so designed to operate at temperatures as specified in
Annex 5O.

ANNEX 4F
PROVISIONS REGARDING THE APPROVAL OF THE FILLING UNIT
(Receptacle)
1. SCOPE
The purpose of this annex is to determine the provisions regarding the approval of the filling
unit.
2. THE FILLING UNIT
2.1. The filling unit shall comply with the requirements laid down in Paragraph 3. and shall have the
dimensions of Paragraph 4.
2.2. Filling units designed in accordance with ISO 14469-1 first edition 2004-11-01 or
ISO 14469-2:2007 and meeting all the requirements therein are deemed to fulfil the
requirements of Paragraphs 3. and 4. of this annex.
3. THE FILLING UNIT TEST PROCEDURES
3.1. The filling unit shall conform to the requirements of Class 0 and follow the test procedures in
Annex 5 with the following specific requirements.
3.2. The material constituting the filling unit which is in contact with the CNG when the device is in
service shall be compatible with the CNG. In order to verify this compatibility, the procedure of
Annex 5D shall be used.
3.3. The filling unit shall be free from leakage at a pressure of 1.5 times the working pressure (MPa)
(see Annex 5B).
3.4. The filling unit shall withstand a pressure of 33 MPa.
3.5. The filling unit shall be so designed to operate at temperatures as specified in Annex 5O.
3.6. The filling unit shall withstand a number of 10,000 cycles in the durability test specified in
Annex 5L.
4. FILLING UNIT DIMENSIONS
4.1. Figure 1 shows the dimensions of the filling unit for vehicles of Categories M and N .
4.2. Figure 2 shows the dimensions of the filling unit for vehicles of Categories M , M , N and N .

Figure 2
20 MPa Filling Unit Size 2 (receptacle) for M , M , N and N Vehicles

3.3.2. The gas flow adjuster of Class 1 and Class 2 shall be so designed to operate at temperatures
as specified in Annex 5O.
3.4. Electrical operated components containing CNG shall comply with the following:
(a)
(b)
They shall have a separate ground connection;
The electrical system of the component shall be isolated from the body.

ANNEX 5
TEST PROCEDURES
1. CLASSIFICATION
1.1. CNG components for use in vehicles shall be classified with regard to the maximum working
pressure and function, according to Paragraph 2 of this Regulation.
1.2. The Classification of the components determines the tests which have to be performed for
type-approval of the components or parts of the components.
2. APPLICABLE TEST PROCEDURES
In Table 5.1 below the applicable test procedures dependent on the Classification are shown.
Table 5.1
Test Class 0 Class 1 Class 2 Class 3 Class 4 Paragraph
Overpressure of strength X X X X O 5A
External leakage X X X X O 5B
Internal leakage A A A A O 5C
Durability tests A A A A O 5L
CNG compatibility A A A A A 5D
Corrosion resistance X X X X X 5E
Resistance to dry heat A A A A A 5F
Ozone ageing A A A A A 5G
Burst/destructive tests X O O O O 5M
Temperature cycle A A A A O 5H
Pressure cycle X O O O O 5I
Vibration resistance A A A A O 5N
Operating temperatures X X X X X 5O
X
=
Applicable
O
=
Not applicable
A
=
As applicable

ANNEX 5A
OVERPRESSURE TEST (STRENGTH TEST)
1. A CNG containing component shall withstand without any visible evidence of rupture or
permanent distortion a hydraulic pressure of 1.5-2 times the maximum working pressure during
minimal 3 minutes at room temperature with the outlet of the high pressure part
plugged. Water or any other suitable hydraulic fluid may be used as a test medium.
2. The samples, previously subjected to the durability test of Annex 5L are to be connected to a
source of hydrostatic pressure. A positive shut-off valve and a pressure gauge, having a
pressure of not less than 1.5 times nor more than 2 times the test pressure, are to be installed
in the hydrostatic pressure supply piping.
3. Table 5.2 below shows the working and burst test pressures according to the Classification of
Paragraph 2 of this Regulation.
Table 5.2
Classification of component Working pressure [kPa] Overpressure [kPa]
Class 0 3000 < p < 26000 1.5 times the working pressure
Class 1 450 < p < 3000 1.5 times the working pressure
Class 2 20 < p < 450 2 times the working pressure
Class 3 450 < p < 3000 2 times the relief pressure

ANNEX 5C
INTERNAL LEAKAGE TEST
1. The following tests are to be conducted on samples of valves or filling unit which have
previously been subjected to the external leak test of Annex 5B above.
2. The seat of the valves, when in the closed position, shall be free from leakage at any aerostatic
pressure between 0 to 1.5 times the working pressure (kPa).
3. A non-return valve provided with a resilient seat (elastic), when in the closed position, shall not
leak when subjected to any aerostatic pressure between 0 and 1.5 times the working pressure
(kPa).
4. A non-return valve provided with a metal-to-metal seat, when in the closed position, shall not
leak at a rate exceeding 0.47 dm /s when subjected to an aerostatic pressure difference of
138 kPa effective pressure.
5. The seat of the upper non-return valve used in the assembly of a filling unit, when in the closed
position, shall be free from leakage at any aerostatic pressure between 0 and 1.5 times the
working pressure (kPa).
6. The internal leakage tests are conducted with the inlet of the sample valve connected to a
source of aerostatic pressure, the valve in the closed position, and with the outlet open. An
automatic valve and a pressure gauge having a pressure range of not less than 1.5 times nor
more than 2 times the test pressure are to be installed in the pressure supply piping. The
pressure gauge is to be installed between the automatic valve and the sample under
test. While under the applied test pressure, observations for leakage are to be made with the
open outlet submerged in water unless otherwise indicated.
7. Conformance with Paragraphs 2. to 5. is to be determined by connecting a length of tubing to
the valve outlet. The open end of this outlet tube is to be located within an inverted graduated
cylinder which is calibrated in cubic centimetres. The inverted cylinder is to be closed by a
water tight seal. The apparatus is to be adjusted so that:
(a)
(b)
the end of the outlet tube is located approximately 13 mm above the water level within
the inverted graduated cylinder, and
the water within and exterior to the graduated cylinder is at the same level. With these
adjustments made, the water level within the graduated cylinder is to be recorded. With
the valve in the closed position assumed as the result of normal operation, air or nitrogen
at the specified test pressure is to be applied to the valve inlet for a test period of not less
than 2 minutes. During this time, the vertical position of the graduated cylinder is to be
adjusted, if necessary, to maintain the same water level within and exterior to it.

ANNEX 5D
CNG COMPATIBILITY TEST
1. A synthetic part in contact with CNG shall not show excessive volume change or loss of weight.
Resistance to n-pentane according to ISO 1817 with the following conditions:
(a)
medium: n-pentane
(b) temperature: 23°C (tolerance according to ISO 1817)
(c)
immersion period: 72 hours
2. Requirements:
maximum change in volume 20%
After storage in air with a temperature of 40°C for a period of 48 hours the mass compared to
the original value may not decrease more than 5%.
Test procedures:
ANNEX 5E
CORROSION RESISTANCE TEST
1. A metal CNG containing component shall comply with the leakage tests mentioned in
Annexes 5B and 5C and after having been submitted to 144 hours salt spray test according to
ISO 15500-2, with all connections closed.
2. A copper or brass CNG containing component shall comply with the leakage tests mentioned in
Annexes 5B and 5C and after having been submitted to 24 hours immersion in ammonia
according to ISO CD 15500-2 with all connections closed.
ANNEX 5F
RESISTANCE TO DRY-HEAT
1. The test has to be done in compliance with ISO 188. The test piece has to be exposed to air at
a temperature equal to the maximum operating temperature for 168 hours.
2. The allowable change in tensile strength should not exceed +25%. The allowable change in
ultimate elongation shall not exceed the following values:
Maximum increase 10%
Maximum decrease 30%

ANNEX 5L
DURABILITY TEST (CONTINUED OPERATION)
Test Method
The component shall be connected to a source of pressurised dry air or nitrogen by means of a suitable
fitting and subjected to the number of cycles specified for that specific component. A cycle shall consist
of one opening and one closing of the component within a period of not less than 10 ± 2 seconds.
(a)
Room temperature cycling
The component shall be operated through 96% of the total cycles at room temperature and at
rated service pressure. During the off cycle the down stream pressure of the test fixture should
be allowed to decay to 50% of the test pressure. After that, the components shall comply with
the leakage test of Annex 5B at room temperature. It is allowed to interrupt this part of the test
at 20% intervals for leakage testing.
(b)
High temperature cycling
The component shall be operated through 2% of the total cycles at the appropriate maximum
temperature specified at rated service pressure. The component shall comply with the leakage
test of Annex 5B at the appropriate maximum temperature at the completion of the high
temperature cycles.
(c)
Low temperature cycling
The component shall be operated through 2% of the total cycles at the appropriate minimum
temperature specified at rated service pressure. The component shall comply with the leakage
test of Annex 5B at the appropriate minimum temperature specified at the completion of the low
temperature cycles.
Following cycling and leakage re-test, the component shall be capable of completely opening
and closing when a torque not greater than that specified in Table 5.3 is applied to the
component handle in a direction to open it completely and then in the reverse direction.
Component inlet size (mm)
Table 5.3
Max. torque (Nm)
6 1.7
8 or 10 2.3
12 2.8
This test shall be conducted at the appropriate maximum temperature specified, and shall be
repeated at a temperature of -40° C.

ANNEX 6
PROVISIONS REGARDING CNG IDENTIFICATION MARK FOR PUBLIC SERVICE VEHICLES
The sign consists of a sticker which must be weather resistant.
The colour and dimensions of the sticker must fulfil the following requirements:
Colours:
Background:
Border:
Letters:
Dimensions
Border width:
Character height:
Character thickness:
Sticker width:
Sticker height:
green
white or white reflecting
white or white reflecting
4 - 6 mm
≥ 25 mm
≥ 4 mm
110 - 150 mm
80 - 110 mm
The word "CNG" must be centred in the middle of the sticker.
Compressed Natural Gas (CNG) Vehicles.