4820-01-145-6461 (20187FM41T)
NSN 4820-01-145-6461 (NIIN 01-145-6461) is a safety relief valve in Federal Supply Class 4820, Valves, Nonpowered — a valve designed to automatically release excessive pressures. Manufacturer part number 20187FM41T (Emerson Automation Solutions Final, CAGE 15187); also referenced as 20187 (Anderson Greenwood Lp).
Key specs: 50 psi maximum single response operating pressure; full characteristics table below. NIIN assigned January 1983; DEMIL A (none required); unit of issue EA (each), $9,135.91 gov standard price; export Schedule B 8481.40.0000; ships at 143 lb / 3.3 cu ft.