4820-01-689-8511 (9601004129)
NSN 4820-01-689-8511 (NIIN 01-689-8511) is a check valve in Federal Supply Class 4820, Valves, Nonpowered — a valve permitting flow in one direction only. Manufacturer part number 9601004129 (Pilatus Aircraft Ltd, CAGE S4080); also referenced as CKRB1876205A (The Lee Co).
Key specs: 5 psi maximum first response operating pressure; full characteristics table below. NIIN assigned July 2020; DEMIL A (none required); ESD/EMI-sensitive.