PilotOperatedCheckValve

Description

The component PilotOperatedCheckValve allows free flow through the check valve from A to B and blocks the reverse flow until the pilot pressure directly proportional to the load in the pilot line, so that the pilot piston can push the check poppet off its seat. The component PilotOperatedCheckValve is the model of a check valve which blocks the flow in the direction from fluidPortB towards fluidPortA. In the opposite direction, from fluidPortA towards fluidPortB, the valve can be set to represent either a throttle or orifice. In addition to pressure at fluidPortA the valve can be opened by pressure at fluidPortPilot.

The locking function is thereby represented by a spring. The Opening pressure difference is the pressure difference necessary to overcome the locking spring force. The opening condition is:

fluidPortA.p + Pilot ratio * Pilot pressure > fluidPortB.p + Opening pressure difference.

with Pilot ratio = Pilot piston area / Check valve seat area

Max. opening pressure difference defines the point where the valve is completely open and the values Nominal volume flow and Nominal pressure difference apply. From Opening pressure difference to Max. opening pressure difference the flow is scaled proportionally.

Throttle

Orifice

The component PilotOperatedCheckValve is not a model of a check valve according to its physical structure. It merely represents the characteristic behavior of a check valve. The dynamic effects which can occur in real valve such as forces due to inertia will be represented by means of the parameter TimeConstant, which is the time constant of an idealized first order mechanical system that can not oscillate.