PRESSURE REDUCTION UNIT

CONSTRUCTION SPECIFICATIONS

The pressure reduction unit is fitted on the right side of the engine compartment.

The unit is single stage diaphragm type, compensated, with water/gas heat exchanger.

It is calibrated for a supply pressure of 0,95 bar (95 kPa) higher than the pressure in the intake ducts.

This device connects the tank and the LPG injectors; it consists of the pressure reduction unit, a cut-off solenoid valve and a prefilter.

The reduction unit is provided with two hydraulic connections for the LPG pipes: one for the high pressure inlet and the other for the outlet to the injector rail.

Two compensation intakes are also present; one is connected to the intake chamber and the other to the air filter by means of hoses. The reference pressure is used to keep the gas outlet differential pressure constant compared to the value in the engine intake circuit.

In addition the unit is fitted with inlet and outlet pipes for the coolant which prevents the formation of ice due to the expansion of gas inside the pressure reduction unit.

1. Cut-out solenoid valve

2. LPG inlet connector (high pressure)

3. LPG pre-filter cover

4. LPG outlet connector (low pressure)

5. Connector for vacuum pipe from chamber to LPG pressure regulator

6. Connector for vacuum pipe from air cleaner to LPG pressure regulator

7. Connectors for coolant inlet/outlet pipes

The regulation unit must not be disassembled. Even if only one component is malfunctioning, the unit must be replaced as a unit.

Only the solenoid valve and the filter can be replaced, as they are fitted outside the body of the reduction unit.

The operation of the pressure regulation unit is characterised by its intermediate position between the tank and the injectors.

In particular the device guarantees that the LPG pressure in the supply circuit (including the injectors) is constant at a value of +0,95 bar compared to the pressure in the engine intake manifold, in order to ensure the correct metering of the LPG injected as a function of the injection time.

The regulation unit is characterised by a solenoid valve which is controlled by the LPG system management control unit.

When this valve opens, the solenoid valve on the tank also opens; in this way, at this moment the LPG enters the actual pressure reduction unit through the pipe.

LOW PRESSURE LPG FILTER

Construction specifications

This device filter the LPG in gaseous state.

The filter inlet and outlet (identified with "IN" and "OUT") are connected to the pressure reduction unit outlet and to the injector rail inlet respectively by means of hoses.