4820-01-523-3206 (5021-2)
NSN 4820-01-523-3206 (NIIN 01-523-3206) is a check valve in Federal Supply Class 4820, Valves, Nonpowered — a valve permitting flow in one direction only. Manufacturer part number 5021-2; also referenced as 5021-2 ASSY S1620C, S1620C (Western Methods Machinery).
Key specs: 275 psi maximum single response operating pressure; full characteristics table below. NIIN assigned August 2004; DEMIL A (none required); unit of issue EA (each), $2,505.09 gov standard price.