E/ECE/324/Rev.2/Add.109/Rev.
5
E/ECE/TRANS/505/Rev.2/Add.109/Rev.5
Annex 4G
Annex 4G
Provisions on the approval of CNG gas flow adjuster and
gas/air mixer, gas injector or fuel rail
1. The purpose of this annex is to determine the provisions on the approval of
the CNG gas flow adjuster and gas/air mixer, gas injector or fuel rail.
2. CNG gas/air mixer, gas injector or fuel rail.
2.1. The material constituting the CNG gas/air mixer, gas injector or fuel rail
which is in contact with CNG shall be compatible with the CNG. In order to
verify this compatibility, the procedure specified in Annex 5D shall be used.
2.2. The CNG gas/air mixer, gas injector or fuel rail shall conform to the
requirements of Class 1 or 2 components, according to their classification.
2.3. Test pressures
2.3.1. The CNG gas/air mixer, gas injector or fuel rail of Class 2 shall withstand a
pressure twice the working pressure.
2.3.1.1. The CNG gas/air mixer, gas injector or fuel rail of Class 2 shall be free from
leakage at a pressure twice the working pressure.
2.3.2. The CNG gas/air mixer, gas injector or fuel rail of Class 1 and Class 2 shall
be so designed to operate at temperatures as specified in Annex 5O.
2.3.3. The CNG gas injector or fuel rail of Class 6 shall withstand a pressure 1.5
times the declared working pressure.
2.3.3.1. The CNG gas injector or fuel rail of Class 6 shall be free from leakage at a
pressure 1.5 times the declared working pressure.
2.3.4. The CNG gas injector or fuel rail of Class 6 shall be so designed to operate at
temperatures as specified in Annex 5O.
2.4. Electrical operated components containing CNG shall comply with the
following:
(a) They shall have a separate ground connection;
(b) The electrical system of the component shall be isolated from the
body;
(c) The gas injector shall be in closed position when the electric current is
switched off.
3. CNG gas flow adjuster
3.1. The material constituting the gas flow adjuster which is in contact with the
CNG shall be compatible with the CNG. In order to verify this compatibility
the procedure specified in Annex 5D has to be used.
3.2. The CNG gas flow adjuster shall conform to requirements of Class 1 or 2
components, according to their classification.
3.3. Test pressures
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