4820-01-440-6185 (C2020S20)
NSN 4820-01-440-6185 (NIIN 01-440-6185) is a check valve in Federal Supply Class 4820, Valves, Nonpowered — a valve permitting flow in one direction only. Manufacturer part number C2020S20 (Parker-Hannifin Corporation, CAGE 09990); also referenced as YMD-6923 (Appleton Marine Inc).
Key specs: 3000 psi maximum single response operating pressure; full characteristics table below. NIIN assigned January 1997; DEMIL A (none required); unit of issue EA (each), $18.78 gov standard price.