4820-00-018-2154 (564)
NSN 4820-00-018-2154 (NIIN 00-018-2154) is a check valve in Federal Supply Class 4820, Valves, Nonpowered — a valve permitting flow in one direction only. Manufacturer part number 564 (William Powell Company, The, CAGE 48422).
Key specs: 300 psi maximum first response operating pressure; 500 psi maximum second response operating pressure; full characteristics table below. NIIN assigned May 1968; DEMIL A (none required).