discharge pressure from the working pump

A controlled or regulated pressure valve (24) is allocated to said positive displacement circulation pump (18) on the delivery side.

In this way, the delivery volume of the pump is controlled.

The delivery side of the return pump (26) runs between the reversing valve (18) and the intake valve (20).

The output of the pump employs a one-way valve (152).

The scrubbing action is achieved by a pump suction which is spaced from a pump discharge.

By seating the discharge head in the tank housing, an annular pump discharge chamber (86) is defined with the housing and between the end walls of the pump.

The pump includes a flexible membrane movable between alternating pump intake and discharge motions.

A system for controlling the pressure output of an engine-driven centrifugal fire pump includes a discharge pressure sensor mounted in the discharge line of the pump.

Fitted on the delivery side of the pump is a high-pressure reservoir (9).

The delivery side of the pump is in communication with a discharge line (28).

The discharge vacuum relief valve is capable of venting a vacuum at the discharge side of the safety vacuum release system pump during a vacuum event at a suction side of the safety vacuum release system pump.

The fuel pump (1, 2) then pumps at full capacity.

In addition, a lubrication flowing quantity which is independently constant from pressure on the pressure side is branched from the feeding current of the low lift pump and a residual cutoff current of the high pressure pump intake side is supplied.

The PID constant in the PID control is selected according to the discharge amount of the high-pressure pump (2) to enable the PID control to follow a change in the discharge characteristics of the high-pressure pump (2).