PressureReducingvalve

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PressureReducingvalve

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Iconic Diagrams\Hydraulics\Valves\Basic Valves

Use

Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Hydraulics).

Description

Pressure reducing valves have the purpose to provide a constant pressure (p_nom), independent of the upstream pressure. They are used to limit the pressure of a primary circuit to a desired pressure for a secondary circuit.

 

The desired pressure (p_nom) is obtained by means of a flow over a valve between an input port (pa) and an output port (pb). The valve is modeled by a variable conductance). Depending on the pressure downstream (pb.p) the valve is opened (large conductance) or closed (zero conductance). Therefore pressure reducing valves always need a small flow to establish the correct downstream pressure.

PressureReducingValve1

When the downstream pressure (pb.p) increases over the desired pressure a second valve opens to allow flow from the downstream port (pb) to a third port (pt). The third port is mostly connected to the tank.

PressureReducingValve2

The valves have a pressure region for opening an closing. This region is indicated by the parameter range.

Interface

Ports

Description

pa

pb

pt

Upstream port

Downstram port

Relief port

Causality

 

fixed volume flow out pa

fixed volume flow out pb

fixed volume flow out pt

 

Parameters

 

p_nom

range

Gab

Gbt

Desired downstream pressure [Pa].

Range for opening and closing the valves [Pa].

The maximum conductance from a to b [m3/s.Pa].

The maximum conductance from b to t [m3/s.Pa].