CounterBalanceValve

    CounterBalanceValve

Library

HydraulicsByFluidon/Components/Valves/PressureValves

Description

The component CounterBalanceValve is a model of a counterbalance valve (or load control valve) with signal based dynamics of the spool.

The following images show how to determine the parameters of the valve.

The flow characteristic of fully opened valve is given by parameters Nominal volume flow and Nominal pressure difference.

Relief and pilot performance diagram gives the parameters Relief pressure A->B and Relief pressure difference A->B.

Pilot ratio is one the main characteristics of a counter balance valve and is given in the data sheet.

Opening pressure difference B->A is a characteristics parameter of the check valve for reverse flow. It can be determined also from free flow diagram. In the presented diagram the opening pressure difference is very small. Typically, values are around 1 bar.

Counterbalance valves are used with cylinders to safely hold suspended loads and deal with over-running loads. This valve can also be used with hydraulic motors and is then commonly called a brake valve. Both counterbalance valves and pilot-operated check valves can be used to lock fluid in a cylinder to prevent drifting. However, a pilot-operated check valve cannot control an over-running load. Whenever uncontrolled movement can occur from an overrunning load, a counterbalance valve should be used.

Parameters

CounterBalanceValve_0

NameLabelDescriptionData TypeValid Values

mo_NominalVolumeFlow

NominalVolumeFlow

Nominal volume flow

Scalar

mo_NominalPressureDifference

NominalPressureDifference

Nominal pressure difference

Scalar

mo_ReferenceDensity

ReferenceDensity

Reference density for volume flow and pressure difference

Scalar

mo_ReliefPressure

ReliefPressure

Relief pressure A->B

Scalar

mo_ReliefPressureDifference

ReliefPressureDifference

Relief pressure difference A->B

Scalar

mo_OpeningPressure

OpeningPressure

Opening pressure difference B->A

Scalar

mo_pilotRatio

pilotRatio

Pilot ratio

Scalar

mo_timeConstant

timeConstant

Response time of valve spool

Scalar

mo_deadVolume

deadVolume

Dead volume at ports

Scalar

mo_enableStrokeOutput

enableStrokeOutput

Enable spool stroke output

Number

0
1

CounterBalanceValve_1

NameLabelDescriptionData TypeValid Values

mo_forwardFluidProperties

forwardFluidProperties

Forward fluid properties between ports

Scalar

true
false

CounterBalanceValve_2

NameLabelDescriptionData TypeValid Values

mo_volumeFlowA

volumeFlowA

volumeFlowA

Structure

mo_volumeFlowA/fixed

fixed

Cell of scalars

true
false

mo_volumeFlowA/start

start

Cell of scalars

mo_volumeFlowB

volumeFlowB

volumeFlowB

Structure

mo_volumeFlowB/fixed

fixed

Cell of scalars

true
false

mo_volumeFlowB/start

start

Cell of scalars

mo_pA

pA

pA

Structure

mo_pA/fixed

fixed

Cell of scalars

true
false

mo_pA/start

start

Cell of scalars

mo_pB

pB

pB

Structure

mo_pB/fixed

fixed

Cell of scalars

true
false

mo_pB/start

start

Cell of scalars

mo_spoolStroke

spoolStroke

spoolStroke

Structure

mo_spoolStroke/fixed

fixed

Cell of scalars

true
false

mo_spoolStroke/start

start

Cell of scalars

Ports

NameTypeDescriptionIO TypeNumber

fluidPortA

implicit

Hydraulic port A

input

1

fluidPortB

implicit

Hydraulic port B

input

2

fluidPortPilot

implicit

Hydraulic port pilot

input

3

Port 4

implicit

Spool stroke

output

mo_enableStrokeOutput