Vickers Proportional Valves Proportional …

1 Revised 11/98539 Proportional Directional and Throttle Valves Solenoid OperatedKDG4V-3S and KTG4V-3S standard performance series K(A)DG4V-3 and K(A)TG4V-3 high performance series ISO 4401-03 (NFPA D03) Pressures to 350 bar (5075 psi) Vickers Proportional Valves2 IntroductionKDG and KTG ValvesVickers KDG and KTG Valves arenon-feedback type Proportional KDG is a Proportional directional valvewith two solenoids (C models). Itincorporates control of flow, direction,acceleration, and deceleration in a singlecontrol KTG is a Proportional throttle valvewith a single solenoid. B models are springcentered with solenoid A removed. Fmodels are spring offset to port A andrespond to an increasing signal byreducing the flow rate. The KTG s spoolcan be infinitely positioned to achievethrottling (restriction) of the fluid primary function of these Valves is todirect and meter fluid flow in proportion tocurrent received by the solenoid.

2 This fluidflow controls the velocity, direction, andacceleration or deceleration of a work cylinder or fluid Valves are designed to fill theperformance gap between conventionalsolenoid operated directional Valves andservo Valves or feedback-type proportionalvalves. They provide control of spoolposition and metered fluid flow inapplications that don t require the highlevels of accuracy, repeatability, orresponse possible with feedback-typeproportional Valves or with Vickers electronic amplifiers,these Valves provide an interface betweencontrol system intelligence and hydraulicmuscle. This is a very practical way tocontrol actuator direction and speed whileeliminating shock caused by rapidacceleration and deceleration of addition to improving machineperformance and life, these proportionalvalves substantially simplify system designby combining direction and flow controlcapabilities in one package that mounts toa standard NFPA/ISO subplate or valve can also be readily tailored to avast array of applications by specifying thespecific valve configuration which best meetssystem valve is controlled by applying currentto either solenoid A or solenoid B.

3 Thiscurrent produces a force at the solenoidpush pin which, in turn, causes spooltravel. The spool will continue its motionuntil the solenoid force is balanced by thereturn spring force. Therefore, spool travelis Proportional to the amount of currentpassing through the solenoid and KATG ValvesThe above description of KDG and KTGvalves also applies to KADG and KATG Valves , with one exception. KA valveshave an integral amplifier, whereas KDGand KTG Valves do control amplifier of KA models ishoused in a sturdy metal enclosure builtdirectly on, and prewired to, the adjustments of gain, balancingdeadband and dither ensure highrepeatability valve-to-valve. The onlyelectrical inputs required are powersupply (24V) and a voltage commandsignal of and Benefits These global products, manufactured toworld-class quality standards, are sold andserviced throughout the world.

4 KDG4V and KTG4V Valves have a lowinstalled cost due to commonality of partswith Vickers DG4V-3(S) solenoidoperated directional valve. These Valves open up expandedapplication opportunities as acost-effective alternative tofeedback-type Proportional and servo Valves . Sustained high machine productivity anduptime result from the proven fatigue lifeand endurance of reliable KDG4V andKTG4V Valves . Vickers flexible design approach providesoptimum performance. A wide variety ofmatching electronic amplifiers, valveoptions, and spool ratings allows thesystem designer flexibility in meetingapplication requirements. All Valves are NFPA fatigue rated at 350bar (5075 psi) for improved reliability andperformance. The fully encapsulated solenoid coils areimpervious to common industrial can be removed and replacedquickly and easily without breaking intothe hydraulic envelope.

5 The Valves standard ISO 4401-03mounting is interchangeable with anyNFPA D03 or CETOP 3 interface. The engineering resin junction box isNEMA 4 rated for resistance to water andall commonly used industrial fluids. Advantages of KADG and KATG valveswith integral amplifier: Factory-sealed adjustments for increasedvalve-to-valve accuracy and simplifiedsystem set-up Valve and amplfierselected, ordered, delivered and installedas a performance-tested package Installation wiring reduced and simplified Simplified valve removal and replacement The use of Viton* O-rings throughoutprovides multi-fluid capability andprevents outside fluids from contactinginternal valve parts.* Viton is a registered trademark of theDuPont InformationTypical Applications, Meter-in and Meter-out, Valve Spool Position, Flow Rates, Recommended Fluids,Pressure Compensation, Accessories, Electrical Signals, Electrical Connectors4.

6 Cross Section of Typical Valve, Graphical Symbols5.. System Calculations for Valve Selection6.. KDG4V-3S and KTG4V-3S Standard Performance Valves 100 bar (1450 psi) tank line ratingModel Code7.. Application DataSpecifications, Performance, Solenoid Specifications, Step Response TimeSpool, Spool/Spring, Metering, Amplifiers, Drain8.. Flow Paths9.. Flow Gain Curves10.. Power Capacity Envelopes13.. Frequency Response 14.. Installation Dimensions15.. EN-427 Feature16.. Electrical Connections17.. K(A)DG4V-3 and K(A)TG4V-3 High Performance Valves 210 bar (3000 psi) tank line ratingModel Code18.. Application DataSpecifications, Performance, Solenoid Specifications, Step Input Time, Amplifiers, Drain19.. Flow Paths21.. Flow Gain Curves22.. Power Capacity Envelopes26.. Frequency Response27.. Electrical Block Diagram for KADG4V-3 and KATG4V-328.

7 Connection Arrangements for KADG4V-3 and and KATG4V-329.. Installation Dimensions30.. Mounting Requirements32.. Fluid Cleanliness33.. 4 General Information Typical ApplicationsThis type of valve is often used in bothmobile and industrial line-of-sight applications where speed and position arecontrolled by an operator. Some examplesare aerial work platforms, entertainmentindustry rides, farm combine controls,material handling equipment, and processcontrols. Any application using aDG4V-3(S) 60-design solenoid operateddirectional valve is a potential applicationfor the KDG4V-3(S) or KTG4V-3(S)The standard performance KDG4V-3S orKTG4V-3S should be used on mostapplications where a tank line pressurerating of 100 bar (1450 psi) isacceptable. The high performanceKDG4V-3 or KTG4V-3 should be used onapplications where a tank line pressurerating of 210 bar (3000 psi) is used electrical input devicesinclude joystick controllers, proportionalpush buttons, potentiometers, power plugs,and amplifier cards.

8 Input devices thatoperate on the principle of direct voltagerather than current control will require theappropriate coil type (GP or HA).Meter-in and Meter-outSystem requirements must be clearlyunderstood and taken into considerationwhen selecting a valve spool. Meter-outspools have the metering notchespositioned between the actuator port andthe tank port, creating a throttle in thehydraulic actuator s return line. Meter-out isthe most common spool configuration andis typically used in applications with overcenter loads and/or requiring spools have the metering notchespositioned between the pressure port andthe actuator port, creating a throttle in thehydraulic actuator s inlet line. Meter-inspools are commonly used with hydrostatmodules for pressure compensation inapplications that don t have an overrunningload as well as in load sensing with both meter-in and meter-outflow characteristics should be specified inapplications where load changes (resistiveto overrunning or vice versa)

9 Will should also be selected whenuncertain system dynamics prevent theselection of specific meter-in or meter-outspool Spool PositionSpring centered and spring offset valveswill be spring positioned unless thesolenoid is energized to silting, any sliding spool valveheld shifted under pressure for longperiods may stick and not spring is recommended that such Valves becycled periodically to prevent this RatesThe rate of flow through a proportionalvalve is dependent on spool position andvalve pressure differential. This is similar toflow through a needle valve. Like a needlevalve, as a Proportional valve is opened,the rate of flow increases, and if thepressure differential across the valvechanges (because of load pressurechanges, for example), the flow will of this phenomenon, rated flow is an arbitrary term, dependent on theabove a needle valve, however, Proportional Valves exhibit an inherentdegree of load compensation wherebyincreasing valve pressure drop hasprogressively less effect on flow rate (seePower Capacity Envelopes on pages 13and 26).

10 To eliminate the effects ofpressure changes, a hydrostat module canbe installed under the Proportional valve toachieve pressure FluidsPetroleum oils are recommended for usewith the KDG4V and KTG4V. Fluorocarbonseals are standard and are suitable for usewith phosphate ester type fluids or blends,water glycol, water-in-oil emulsion fluids,and petroleum oils. Refer to publication694 for fluid and temperaturerecommendations. HWBF (95% water) isnot CompensationFor information on using a SystemStakreducing valve to achieve pressurecompensation control, please contact yourVickers page 32 for information onmountingsurface, subplate, and bolt SignalsIt is important to note that solenoid forceand valve flow are Proportional tocurrent not voltage. Therefore, foroptimum performance, a constant currentelectrical signal should be used.