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Small 3 Way Valve
The Mac direct acting poppet valve adopts a unique solenoid design, coupled with other special features. This technology is used in the smaller Mac valves, and in the larger spool valves as a solenoid air pilot force.
A short stroke from the solenoid ensures a high shifting force to energize, allowing for a strong return spring and hence a high shift force to de-energize. Air passes over the poppet through an annular section. This annular section means sealing areas are of equal size, that forces created by air pressure are equal in both directions, and the valve is balanced. As a result the high shifting forces are unaffected by changing air pressure on the ports.
With the Mac poppet valve the solenoid stroke is longer than the valve stroke, offering wear compensation and continued operation. The solenoid design means that regardless of the position of the valve, the solenoid can close, virtually eliminating coil burnout an AC applications.
Seals are utilized at each end of the Mac poppet with a unique section, these promote a wiping action within the valve, keeping friction low and ensuring that shifting forces are virtually unaffected by typically contaminated air.
The valve design allows for constant high flow, maintained throughout the pressure range, and a full flow exhaust. With universal porting available, there are six functions available in one valve.
Small 4 Way Valve
The 4 way direct solenoid poppet valve also adopts the Mac solenoid design, and shares all the features of the three way poppet valve. Internally there are effectively four balanced poppets on a one-piece valve stem.
The exhaust seals are not under inlet pressure, thus reducing friction. When the valve shifts, the end poppets seal first on conical seats cushioning the inlet poppet, and eliminating cutting. With direct action, high shifting forces, and minimized friction the valve offers a fast response and high flow in a small package. These features of the 4 way individual valve, are also used as a solenoid air pilot for some of the larger spool valves from Mac.
Large 4 Way Spool Valves
Within a valve, a high shifting force in both directions results in high reliability. Spool valves use an air pilot valve as a drive force, and an air/spring return as a return mechanism. The unique patented MAC solenoid provides a powerful drive force, which in turn allows for a stronger return force to be used. When big surface areas are used on both ends of a main valve spool, reliability can be improved even more.
The Mac patented spool and bore combination ensures low friction. Chemically hardened bonded seals eliminate valve creep. Precision ground, bonded spools control compression leading to optimum sealing and minimum friction. Lubricant within the rubber compound enhances non-lube service.
Large 3 Way Valves
The larger 3 way valves are solenoid pilot, or air pilot operated. They use the same precision ground, bonded spools found in the other Mac valves. The Mac design incorporates a checked air accumulator, which feeds the air spring and pilot. The check valve protects the accumulator from inlet pressure fluctuations.
Please do not hesitate to contact us for any enquiries for MAC Valves products or for applications requiring the innovative, professional and responsive approach that MK Air Controls provides. All are usually held in stock at our 16000 sq ft
purpose built facility in Bedfordshire, England
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