4820-00-289-1882 (20051B)
NSN 4820-00-289-1882 (NIIN 00-289-1882) is a safety relief valve in Federal Supply Class 4820, Valves, Nonpowered — a valve designed to automatically release excessive pressures. Manufacturer part number 20051B; also referenced as 20051B 15-AA-55 (Anderson Greenwood Lp).
Key specs: 150 psi maximum single response operating pressure; full characteristics table below. NIIN assigned January 1963; DEMIL A (none required); unit of issue EA (each), $672.31 gov standard price; export Schedule B 8481.40.0000.