Relief Valves Application Since all hydraulic equipment is designed for a specific maximum operating pressure, the function of a relief valve is to protect the system against undesirable pressure build-ups and excessive structural loads. Relief valves are usually installed facing the system pressure with outlet port connected to a return line. Pressure differential relief valves are sensitive to back pressure and therefore normally not used when high pressure build-ups in the return system can occur. When limitation and control of excessive pressures are required at intermediate points of the system, balanced type relief valves are used. These valves are generally referred to as Priority Valves, and being internally balanced to back pressure, their operation is unaffected by downstream pressure build-ups. Design Characteristics: Suitable for in-line applications or installation in modules with other valves or as part of larger assemblies. Stainless steel working parts for corrosion and wear resistance. Springs used are usually made of 17-7PH CRES to withstand high loading stresses for minimum weight. Also, springs are shot peened, if required, to improve fatigue strength and performance. To maintain constant pressure setting during temperature changes from -65° to +275°F, all internal working parts are made of materials especially selected for the smallest coefficient of thermal expansion available. Who Is Arkwin? Arkwin Industries is the technical expert in all things hydraulic for aerospace and defense. We design, test, manufacture, and support precision hydraulic and fuel system components for civil and military fixed-wing aircraft, helicopters, spacecraft, turbine engines, and other special applications. Our reputation for quality and reliability, as well as our location, allow us to attract some of the best engineering, technical, and manufacturing talent available.

Relief Valves Design Characteristics For long and failure free service life, the seat and poppet are made of highly hardened corrosion resistant steel. A very unique “artificial lift” design feature developed by Arkwin, uses the dynamic forces of the fluid flow to raise the poppet off its seat to achieve a wide effective flow orifice within a small valve envelope. As a result, Arkwin’s valves are of smaller size than envelopes per MS28887 and exceed the flow requirements. Performance Data Arkwin’s basic line of relief valves has been qualified to MIL-5523, MIL-V-8813 and to many stringent customer...