Circle Seal Controls O f f e r s Free L i t e r a t u re On C h e c k - R e l i e f V a l v es
The functions of both a check valve and a relief valve are performed by the P-389 Series Check- Relief Valves from Circle Seal Controls. They provide free flow in one direction, zero leakage in the reverse direction, with an internal thermal relief unit.
The P-389 Series valves prevent back flow or back leakage in a liquid or gas system with their check mechanism. A check valve opens at a low cracking pressure and has a low pressure drop. A poppet spring insures that the valve is closed before start of return flow. The Circle Seal floating O-Ring positions automatically for perfect line-of-contact sealing.
The internal relief mechanism protects the system down stream of the valve from overpressure resulting from thermal or other causes.
Being combined internally with the check valve, it eliminates the need for an external relief unit and its incumbent piping. The relief mechanism seals with no leakage, virtually to cracking pressure.
Typical applications for the P-389 Series include air, oil, or fuel supply line to reservoir tank. Or, they can be used on the suction side of hydraulic pump to prevent loss of prime or flooding of reservoir tank; also used as vacuum and pressure relief.
Available made of aluminum or 303 stainless steel, in sizes for tubing ranging from lA inch to 1 inch. Operating temperatures range from - 6 5 F. to +275 F.
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