LoopFlushingValve

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LoopFlushingValve

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Iconic Diagrams\Hydraulics\Valves\Basic Valves

Use

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

Description

Loop flushing valves are used to maintain a high quality working fluid in closed hydraulic circuits.  In closed hydraulic circuits  the oil is continuously flowing from a pump to an actuator. A loop flushing valve allows the oil to leave the circuit for cooling and filtering. If one side (pa) of the valve has a higher pressure, oil will flow from the other side (pb) out of the closed circuit and vice versa.

LoopFlushingValve

The circuit is always equipped (not shown above) with a charge pump to keep the suction side of the pump on a pre-pressure to avoid cavitation and so damage to the pump, and to exchange the fluid that is flushed.

 

Loop flushing valves are spring operated. I.e. a certain pressure difference between port a and b is required to open the valve. This pressure can be adjusted and is indicated by the parameter p_sw.

 

LoopFlushingValveDiagram

 

A small pressure difference is required to turn a valve from completely closed to completely opened. This overlap pressure is indicated by the parameter p_o.

Interface

Ports

Description

pa, pb

p_out

Input terminals of the valve.

Output terminal.

Causality

 

fixed volume flow out pa

fixed volume flow out pb

fixed volume flow out p_out

 

Parameters

 

p_o

p_sw

Q_nom

p_nom

f

d

GLeak

Overlap pressure [Pa].

Switching pressure [Pa].

Turbulent flow at nominal pressure drop [m3/s]

Nominal pressure [Pa].

Bandwidth of the spool dynamics [Hz], f > 0, (hidden).

Damping of the spool dynamics [], d > 0, (hidden).

Conductance of the laminar leakage flows [m3/s.Pa], GLeak >= 0. (hidden).