Introduction to Cartridge Valves

2

Cartridge ValvesIntroduction

The cartridge valve, with nearly30 years of successful applicationsexperience, holds a unique positionin the fluid power industry. Itssmall size, fast switching speeds,and cost effective design, make itan integral part of many motioncontrol and fluid power systems.Moog’s extensive experience in theapplication of cartridge valvetechnology allows us to offer oneof the most complete line ofcartridge valves, ranging in sizesfrom 16 to 160, as per DINstandard 24342 for sizes 16 to100. In addition to our standardcartridge valves, Moog also offers acomplete line of high flow andactive cartridge valves for morespecialized and higher performancefluid power systems.

The combination of differentMoog cartridge valves, cover platesand if necessary, pilot valves, canlead to configurations thatreplicate check, directional,pressure, and flow control devicefunctionality. Individual Moogcartridge valve catalogs illustratehow cartridge valves and coverplates can be combined toproduce different functions, andpresent the entire product offeringin a way to make ordering easy.

Cartridge valves consist basicallyof a sleeve (1), valve poppet orcone (2), and closing spring (3).

The cartridge assembly isdesigned to fit within a cavitydefined by DIN 24342, and is heldin place and sealed by a cover.

The manifold block acts as thevalve housing and contains portsA and B together with the pilotcontrol lines.

The control cover contains thepilot control drillings, thus also actsas the connection between thepilot side of the cartridge valve(spring side and the connection X).

3

Cartridge ValvesIntroduction

12

3

3

2

1

X

A

B

Cartridge ValvesHow They Work

4

Cartridge valves, also known as2/2–way valves or logic valves, havetwo operational ports A and B.The flow path between these twoconnections is controlled hydraulicallyby a pilot pressure applied to X.Thebasic cartridge valve includes a valvepoppet sleeve which is normally heldin the closed position by a spring.Thepoppet valve has a seated cone, givinga near zero leakage (dependent uponpilot control) condition across the twoports.The closing spring is retained bythe control cover which encloses thecartridge valve and provides pilotconnections from the X port.Varioustypes of pilot control can be mountedeither to the control cover or to anadjacent manifold face, to providedirect control of the cartridge valve.

The effective areas of the basicelement are AA,AB and AX. Pilot oil canbe taken from port A, B or both Aand B (with a shuttle valve), or anexternal source. Hydraulic fluid canflow through the 2–way cartridgevalve from A➔ B or B➔ A.

If a pilot valve is used, it candirectly control the switching functionof the cartridge valve, either betweentwo extreme positions, open or closed,or in any number of intermediatepositions.The exact position of thevalve cone depends on the ratio ofcontrol surface AX to the pressuresacting from the working connectionsA and B on the seating surface of AA

and the annular area of AB.(See Figure 3)

If the valve cone is open, by reducingthe pressure seen at X, then flow canmove from A and B or vice-versa. Byapplying a control pressure at X, theworking connections A to B are shutoff as the valve cone is closed by theseat mounting. If there is a pressuredifference between connection Band pilot connection X as a resultof clearance tolerance between thecone and sleeve, then leakage canbe eliminated by using a leakproofseat valve and hooking up the pilotconnection X to the workingconnection B. If the desired functiondoes not permit such a switchingoperation, a cartridge valve with anadditional sealing surface can be usedto seal the connections A, B and Xfrom each other.

Figure 2

X

AX

AB

B

A

AA

Figure 3

The Operation of LogicElements is Always PurelyPressure Dependent

The three areas which are importantfor the functioning of a cartridgevalve are:

➣ The area of the valve seat AA.➣ The annulus area at port B (AB).➣ The area on the spring side

AX, which is the sum of theareas AA and AB.

➣ The ratio of AA to AX isnormally 1:1.6 for standardcartridge valves and 1:2 forhigh flow valves.

The Following is then Valid:

Areas AA and AB operate in theopening direction.Area AX and thespring have a closing effect on thevalve.The summation of the openingand closing forces determineswhether the logic element will openor close.When no pressure is appliedto the valve, the poppet sits down onits seat. By applying pressure to areaAX usually from port A, or port B, orA and B via a shuttle valve, the valvepoppet can allow a free connectionA to B.

Closing forcesPX • AX + spring force

Opening forcesPA • AA + PB • AB

Cartridge ValvesHow They Work

5

Cartridge ValvesApplication

Application

Again, cartridge valves have twoworking connections A and B wherethe main flow is hydraulically operatedby a controlling current applied to theconnection X.

Depending on the control input,these valves can be used as:

➣ Directional control valves (start, stop, directional control)

➣ Pressure control valves(pressure relief, pressurecontrol, pressure sequenceand unloading function)

➣ Check valves(check valve functionand pilot operatedcheck valve function)

➣ Flow control valves

The preferred mode of mountingis the manifold block, which can beequipped with several valves dependingon the hydraulic circuit for the specificapplication. Each valve is connected toeach other in the manifold block.

The Moog manifold systemsproduct line contains valves of nominalbores 16, 25, 32, 40, 50, 63, 80 and 100as per DIN 24342 for flows up to10,000 l/min., and sizes 125, 160 up to24,000 l/min. with cover plates andpilot valves for various functions.

In addition to this, our productoffering also contains cartridgehousings for a great number ofapplications for subplate, pipe andflange mounting.

6

7

Cartridge Valve Control

Since cartridge valves can be utilizedin such a manner as to replicatethe functionality of flow, pressure,directional and check control, a systemcomprised of cartridge valves mountedin a manifold block can be designed toreproduce the functionality of theconventional hydraulic system.Thevalve functionality can be relocatedfrom the working circuit to the control

circuit, thereby simplifying the circuitcomplexity. Furthermore, the numberof space intensive single function valvesis reduced, or eliminated outright,creating a space savings. Lastly, thepressure drop across a cartridge valveis often less than a correspondingsingle function valve, resulting in areduction of system losses.

Conventional Control withSingle Function Valves

In a conventional hydraulic system, thesystem’s functionality is achieved byconnecting single function valves in aparallel or serial fashion.The inclusionof flow, directional, pressure or checkcontrol single function valves results ina system which requires more valves,more space, greater system losses andincreased weight.

Features and Benefits of Cartridge Valves

Feature Benefit

➣ Increased power density ➣ Smaller system size➣ Several functions at one mounting position ➣ Reduced system cost➣ Fast switching times ➣ Enhanced system response➣ Mounting within a manifold ➣ Reduced chance of oil leakage➣ Soft switching ➣ Fewer system pressure spikes➣ Single contact point within valve ➣ Improved component life➣ Large flow range ➣ More cost effective control in high flow systems➣ Low pressure drop ➣ Reduced energy consumption➣ Higher permissible operating pressures (up to 5,000 psi) ➣ More cost effective control➣ Low sensitivity to contamination ➣ Longer field life without maintenance➣ Unlimited holding time and special safety certifications ➣ Ideal for safety circuits➣ Insensitive to water based fluids ➣ Greater stability across all operating conditions➣ Insensitive to high pressure drops ➣ Can be used in super high flow systems and

hazardous environments

Cartridge ValvesComparative Advantages

8

A

B

Pressure Control Valves

To reproduce the functionality of apressure control valve, the cartridgevalve is usually utilized as a main stage;therefore, the control surface area AX

and the cone surface area AA shouldcorrespond to a ratio of 1:1 for anoptimized function.This is guaranteedby a cartridge valve with cone A andthe matching sleeve A. Note, however,that there can only be a flow from Ato B in this cartridge valve.

In order to improve the controlreaction within the same range, acartridge cone with a dampening nosecan be used.Accordingly, the cartridgeis then composed of a sleeve A and acone D with a cone ratio of 1:1.

Again, the flow direction is onlyfrom A to B.

A

B

Check Valves

If a cartridge valve is to be used as acheck valve, the control surface area AX

must be bigger than the cone surfacearea AA.

A special cone R makes it possibleto minimize the installation effort ofthe check valve function in the controlunit, by eliminating the need foradditional control drillings and specialcartridge covers.A cartridge valvecomprised of sleeve B and cone Rflows freely from A to B andcompletely shuts off flow from B to A.

Directional Control Valves,Check Valves and FlowControl Valves

A cartridge valve which permits flowsin either direction (A B), isrequired for directional control, check,and flow control valve applications. Inthese situations, cones with a controlsurface area AX that is larger than thecone surface AA (AX > AA) must beused, therefore, the cone surface areaAB must not be 0.

For directional control, check, andflow control applications, a cartridgewith a sleeve B and cone B is specified.Soft switching operations are the resultof the difference between controlsurface area AX and cone surface AA.

In order to avoid pressure peaks intank circuits, or to better adjust flowcontrol valves, the cone B can bereplaced by a cone with a dampeningnose such as cone C.

Cartridge ValvesCreate Single Valve Functionality

A cone/A sleeve B cone/B sleeve

A

B

A

B

D cone/A sleeve C cone/B sleeveA

B

R cone/B sleeve

9

The Moog Cartridge ValveProduct Line

Moog’s cartridge valve product lineconsists of three types of valves:

➣ Standard cartridge valves➣ High flow cartridge valves➣ Active cartridge valves

The below matrix illustrates the flow ranges that delineate ourstandard and high flow lines.

Standard and High Flow Valve Flow RatesFlow at 90 psi drop (6 bar)

Size Standard High Flow

NB16 53 gpm (200 lpm) 86 gpm (325 lpm)

NB25 120 gpm (450 lpm) 178 gpm (675 lpm)

NB32 225 gpm (850 lpm) 290 gpm (1,100 lpm)

NB40 400 gpm (1,500 lpm) 422 gpm (1,600 lpm)

NB50 800 gpm (3,000 lpm) 925 gpm (3,500 lpm)

NB63 1,200 gpm (4,500 lpm) 1,385 gpm (5,250 lpm)

NB80 1,850 gpm (7,000 lpm) 2,180 gpm (8,250 lpm)

NB100 2,640 gpm (10,000 lpm) 3,350 gpm (12,700 lpm)

NB125 3,700 gpm (14,000 lpm)

NB160 6,340 gpm (24,000 lpm)

Cartridge ValvesProduct Line

Moog’s active cartridge valves are aseparate line of product which is basedon our standard valve, but offersenhanced levels of control. Moog’sactive cartridges were designed toaddress the limitation of standardcartridges – closing time, opening time,tightness, prefill valve function, controlpressure, closing under load, and lack offeedback.

Our active cartridge valvesinclude an additional control area,which provides enhanced control ofswitching forces.This enhanced levelof control is critical for higher speedor faster response applications, wherelow system pressure can delay theclosing process.

10

Standard Cartridge Active Cartridge

Cartridge ValvesProduct Line

11

The Primary Benefits ofMoog’s Active CartridgeValves are:

➣ Large flow range➣ Compact installation dimension➣ Short operational times➣ Minimal pressure peaks➣ High functional reliability

Furthermore, Moog activecartridge valves can perform a prefillfunction, something traditionalcartridges cannot.

In conclusion, Moog proudly offersto you our most complete line ofcartridge valves yet. We present thedetails of each of our cartridge valves –standard flow, high flow and active – ina series of separate brochures. Eachvalve is profiled in its own brochure,with product options consisting of:

➣ Size➣ Cone and sleeve configuration➣ Cover type➣ Orifice

Cartridge ValvesUnique Benefits

ArgentinaAustraliaAustriaBrazilChinaEnglandFinlandFranceGermany

IndiaIrelandItalyJapanKoreaLuxembourgNorwayRussiaSingaporeSpainSwedenUSA

Moog Inc., East Aurora, NY 14052-0018Telephone: 716/655-3000Fax: 716/655-1803 Toll Free: 1-800-272-MOOGwww.moog.com

CDL6669 Rev A 500-355 301