4820-00-621-1237 (038-001A043)
NSN 4820-00-621-1237 (NIIN 00-621-1237) is a check valve in Federal Supply Class 4820, Valves, Nonpowered — a valve permitting flow in one direction only. Manufacturer part number 038-001A043 (National Fluid Seperators, CAGE 64707); also referenced as 2259B6MM (Circor Aerospace, Inc.).
Key specs: 250 psi maximum single response operating pressure; full characteristics table below. NIIN assigned February 1975; DEMIL A (none required); unit of issue EA (each), $24.58 gov standard price; ships at 0.38 lb / 0.0047 cu ft. Supersedes 4820-01-337-1575 (1992).