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Depending on the equipment, one or another executive
mechanism may be installed.
Automotive fuel electropumps can be rotary roller or gear
type, single or multi-sectional. The fuel pump can be located
outside the tank, and directly be immersed in gasoline in and
designed to maintain a constant pressure drop between the air
pressure in the inlet pipe and the fuel pressure in the ramp. The
fuel pressure regulator consists of a valve 5 (Fig. 6.1) with an
aperture 4, a spring pressed to the saddle in the regulator
housing.

1 - body; 2 - cover; 3 - branch pipe; 4 - diaphragm; 5 -
valve; A - fuel cavity; B - vacuum cavity
Figure 6.1 - Appearance of the fuel pressure regulator

On a running engine, the regulator maintains the pressure
in the injector ramp, depending on the car model, within 250-
325 kPa. On the diaphragm of the regulator on one side is the
pressure of fuel, and on the other hand - the pressure (dilution)
in the inlet pipe.

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