4820-00-721-9927 (1-2B1-3 48212B13)
NSN 4820-00-721-9927 (NIIN 00-721-9927) is a check valve in Federal Supply Class 4820, Valves, Nonpowered — a valve permitting flow in one direction only. Manufacturer part number 1-2B1-3 48212B13; also referenced as 19772 (Tyco Fire Products Lp); 482 1-2B1-3 (Teledyne Industries IncTeledyne).
Key specs: 100 psi maximum single response operating pressure; full characteristics table below. NIIN assigned July 1971; DEMIL A (none required).