1245 / 1428
FUEL SYSTEM
14
E. PRESSURE REGULATOR:
Function:
It reduces pressure from 200 bars (working
pressure) to 4 ± 0.1 bar pressure of CNG. A 150
microns filter is inbuilt inside the Pressure regulator
that filters CNG from dust particles. An electrical
solenoid is also mounted on the Pressure regulator
that allows and stops gas flow to Regulator. There is
an over pressure relief valve which automatically
opens if pressure inside regulator increases up to 9.5
± 0.5 bar. A high pressure sensor is also connected
on the inlet of the pressure regulator to monitor any
leakage in high pressure line.
Working Principle:
The regulator supplies the gas at the working
pressure to the injectors. This is done by decreasing
the pressure of the gas coming from the CNG tank
(normally at 200bar). The output pressure is
calibrated to maintain constant differential pressure
of 4 ± 0.1 bar (gas pressure at rail – manifold
pressure).
Mounting Location:
Pressure regulator is mounted in the Engine
compartment on long member. The Safety
solenoid valve is integrated on the pressure
regulator.
Technical Specifications of Solenoid coil / valve:
Nominal Voltage:
12V DC
Operating voltage:
8V to 16V
Nominal power rating:
13.5 W
Resistance:
10.6 ± 5%
System Integration:
The ECU by controlling the Safety solenoid valve
controls the gas flow to the downstream low
pressure circuit. On activation of the solenoid valve
the CNG enters the regulator. The single stage
regulator expands the gas and delivers the gas to
the gas rail at the required pressure.
Solenoid coil end Pin assignment (on connector):
1: -ve (Supply from power relay)
2: +ve (ECU pin)
Wiring details (ECU & Solenoid coil)
Stand Alone Diagnosis:
(At NTP conditions)
Use Multimeter:s
Coil resistance of solenoid valve @ 20°C =
10.6 ± 5 %
Use TATA Diagnostic Tool & perform actuator
test.
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