4820-01-151-2574 (2020501641M)
NSN 4820-01-151-2574 (NIIN 01-151-2574) is a safety relief valve in Federal Supply Class 4820, Valves, Nonpowered — a valve designed to automatically release excessive pressures. Manufacturer part number 2020501641M (Emerson Automation Solutions Final, CAGE 15187); also referenced as 20205 (Anderson Greenwood Lp).
Key specs: 250 psi maximum single response operating pressure; full characteristics table below. NIIN assigned April 1983; DEMIL Q (Commerce Control List); unit of issue EA (each), $26,675.14 gov standard price; export Schedule B 8481.40.0000; ships at 150 lb / 0.4861 cu ft.