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TSM 240 Applied Fluid Power

Cartridge Valves

Principle Types of Valves

PRESSURE FLOW DIRECTION

CONTROL VALVES

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Cartridge Valve Conceptz Manifold Block design

y remove unnecessary lines, fewer leakage pointsy increase safety, reduced noise levels, smaller

packagesy consolidate systems for diagnostics,

easier/cheaper repairz Two types of cartridges

y screw-in - precise controly slip-in - high flow capacityy individual or mixed blocks

Screw-in Cartridge Valves Manifoldsz Types

y Directional , load-holding, logicvalves

z Flow limitsy 2 to 120-140 L/min (0.5 to 30-

35 GPM)z Can mount in any orientationz Used in

y control circuitsy low flow work circuits

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Screw-in Cartridgesz Standard cavities

y 2 Way, 3 way, 4 wayz Provide a number of 1-2 position valves

2 way2 way 3 way3 way 4 way4 way

Two Way Valves

••DCV’sDCV’s

••ReliefRelief

••NeedleNeedle

••CheckCheck

11 22 11 22

11 22

11 22

11 22

11

22

DCVDCV

ReliefRelief

NeedleNeedle

CheckCheck

444

Three-way Valves

z 2 position DCV’sz Piloted-operated

checkz Sequence valve

11

22

33

11 22

3311 22

33

11 2233

DCVDCV SequenceSequencePilot-opPilot-opcheckcheck

Four Way Valves

z 2 position DCV’sy pilot operated - >23L/min or 6 GPM

z Sequence valves11

22

3344

11

22 3344

11223344

33 22

44

11DCVDCVSequenceSequence

555

Let’s Try an Example

Modify the design of this basic circuit with a the solenoidModify the design of this basic circuit with a the solenoidactivated DCV on the previous slide so that the motor canactivated DCV on the previous slide so that the motor canturn in both directions and normally is stopped. Which partsturn in both directions and normally is stopped. Which partsof the circuit are at system pressure for the differentof the circuit are at system pressure for the differentmodes of operation?modes of operation?

PRESSURE CONTROL VALVES

z Pressure Relief, Pressure Reducing Valvesy To limit or reduce pressure

z Sequence Valvesy To sequence hydraulic operations

z Unloading Valvesy To unload the pump during slack cycles

z Counterbalancey To hold a load

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Pressure Relief

z To limit or reduce pressurez Direct Acting or Pilot Operated

Unloading Valves

A common use of an unloading valve is to dischargeA common use of an unloading valve is to dischargethe fluid of a fixed displacement pump when it is notthe fluid of a fixed displacement pump when it is notin use in a circuitin use in a circuit

An unloading valveAn unloading valveprovides power savingsprovides power savingsfor non-working systemsfor non-working systems

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Example

A fluid power system has a 10.54 cmA fluid power system has a 10.54 cm33/rev pump and a /rev pump and a rated speed of 1800 rpm. The system pressure relief valve rated speed of 1800 rpm. The system pressure relief valve is set for 10.3is set for 10.3 MPa MPa. When the system is idle, all oil is . When the system is idle, all oil is dumped to the reservoir over the pressure relief valve. dumped to the reservoir over the pressure relief valve. Is fluid power used when this circuit is inactive? If yes, Is fluid power used when this circuit is inactive? If yes, how much?how much?

Pressure Reducing Valves

Supply branch circuits withSupply branch circuits withfluid at a lower pressure thanfluid at a lower pressure thansystem pressure.system pressure.

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Sequence ValvesControls the order ofControls the order ofoperations in branchoperations in branchcircuitscircuits

The sequence valve is normallyThe sequence valve is normallyclosed. It is set to react to aclosed. It is set to react to asystem pressure less than thesystem pressure less than thesetting of the pressure reliefsetting of the pressure reliefvalve.valve.

Pressure increases resultingPressure increases resultingfrom an actuator reaching thefrom an actuator reaching theend of its stroke open theend of its stroke open thesequence valve.sequence valve.

Clamp-Drill Circuit

ClampClamp

999

Counterbalance Valves

Direct PilotDirect Pilot

OptionalOptionalRemoteRemotePilotPilot

Unloading valve is set to 10% above the system pressure Unloading valve is set to 10% above the system pressure required to hold the load. required to hold the load.

Counterbalance ValvesCounterbalance Valves

Direct PilotDirect Pilot

Determine the unloading valve settingDetermine the unloading valve settingrequired to hold the load?required to hold the load?

9090 kN kN

300 cm300 cm22

150 cm150 cm22

101010

Answer

Pressure required to hold the load:Pressure required to hold the load:

MPap

p

cmkN

AF

621509010

10

==

=

⋅⋅⋅

⋅

Set the unloading valve for a 10% higher pressure:Set the unloading valve for a 10% higher pressure:

MPa6.6=p

Flow Control

z Fixed or Variablez Compensated

y for Pressure and Temperaturez Flow Divider

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Flow Divider Valves

z Directs flow 2 or more circuitsz Controls flow...but also control direction.z Common on off-road equipment to divide flow

between circuits (e.g., power steering andfront-end load or left and right crawlertracks)

Logic Valvesz Differential pressure sensing

y controls pressure, flow directionz Modulating orificez 2-way hydrostats

y Pressure compensation of flow controlz 3-way hydrostats

y Pressure compensation of priority flow

121212

Slip-in Cartridge Valves Manifoldsz Used for large flow

requirementsy 200-7000 L/min (53 to

1850 GPM)z Components

y slip-in cartridgey cover to retain cartridgey Valve function block

Slip-in Cartridges

AA

BB

CoverCover

Slip-inSlip-inCartridgeCartridge

APAP

z 2 way, 2 positionpoppets

z 2-port check valvesz sleeve, spring,

poppetz Pressure at A, lifts

poppet and allowsflow to B

z Control Pressure APand spring forcehold poppet closed

z Area ratio: AA: AAPy 1:1 - Pressurey 1:2 - Directiony 1:1.1- Both

131313

Slip-in Cartridges

AA

BB

APAP

AA

BB

APAP

z Covers and attached valves add the functionsz Simple valve, unlimited possibilities