4820-00-851-4111 (4-2959-11)
NSN 4820-00-851-4111 (NIIN 00-851-4111) is a safety relief valve in Federal Supply Class 4820, Valves, Nonpowered — a valve designed to automatically release excessive pressures. Manufacturer part number 4-2959-11 (Teledyne Industries IncTeledyne, CAGE 86768); also referenced as 10685, B10685 (Parker-Hannifin Corporation); 4-2959-13, 629X3-16 (Teledyne Industries IncTeledyne).
Key specs: pressure tight outlet side; 3000 psi maximum single response operating pressure; full characteristics table below. NIIN assigned January 1962; DEMIL A (none required); export Schedule B 8481.40.0000. Supersedes 4820-00-821-8025 (1960).