Technical Information
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2.3.10. Fuel system
The fuel system consists of the fuel(CNG) tank, fuel regulator, fuel metering valve, air-fuel mixer
and fuel lines such as pipes and hoses. All parts are should be carefully managed because the fuel
pressure in this system is very high. Leak check should be performed regularly to all connections.
Compressed nature gas is stored in the tanks up to 250bar.
Each tank includes a manual shut-off valve containing a pressure relief valve designed to vent at
either high pressure or high temperature. Each tanks' relief valve is plumbed into a common vent
pipe that routes out of the vehicle.
CNG flows out of the individual tanks, and into a high pressure rated, stainless steel common fuel
line. The fuel lines are joined by high pressure rated stainless steel compression fittings. Any tank
with its Lock-off valve open feeds fuel into the common fuel line. With its shut-off valve closed, the
tank doesn't feed the common line, but the valve's tee is exposed to common line high pressure.
From there, fuel flows to the fuel pressure regulator. The pressure regulator drops fuel pressure to
approximately 8bar. From the regulator, fuel flows to the fuel metering valve containing a low
pressure shut-off solenoid valve.
The fuel gauge on the dash of the vehicle is operated by the engine ECM. The ECM measures fuel
pressure on the fuel pressure regulator with the natural gas tank pressure(NGTP) sensor and fuel
temperature with the natural gas tank temperature (NGTT) sensor on the common fuel line, then
calculates CNG fuel volume and operates the fuel gauge accordingly. The ECM won't sense any
CNG in a tank with a closed shut-off valve.
Gas filter
Manual valve
High press. lock-off valve
Low press. shut-off valve
K
K
N
A
T
N
A
T
A
S
G
A
S
G
Fuel metering valve
Fuel mixer
Combustion
chamber
Throttle valve
Gas regulator
Gas thermostat
Heat exchanger
ED2OM015
Содержание GL08K
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Страница 151: ...Maintenance 145 7 Vehicle wiring harness EH3M5012 Truck engine Bus engine ...
Страница 193: ...Appendix 187 Engine Assembly Bus EJ3OM012 ...
Страница 194: ...Appendix 188 Engine Assembly Truck EJ3OM013 ...
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