The Valve,relief,pressure and Temper, cataloged under National Stock Number 4820-01-640-6689, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 11 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-640-6689 |
| Item Name | Valve,relief,pressure and Temper |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| First End Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Temp Rating | 140.0 FAHRENHEIT DEGF |
| Second End Relationship with First End | NOT IDENTICAL |
| Body Style | STRAIGHT THRU |
| First End Thread Class | 3H |
| Body Outside Diameter | 1.000 INCHES NOMINAL IN |
| Supplementary Features | ONE INLET; TWO OUTLETS |
| End Connection Quantity | 1 |
| Opening Pressure Setting | ERR-060 |
| Second End Width Across Flats | 1.000 INCHES NOMINAL IN |
| First End Nominal Thread Size | 0.4375 INCHES IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 23942175-1 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-640-6689 is a Valve,relief,pressure and Temper, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-640-6689: First End Thread Series Designator: UNIFIED NATIONAL JOINT FINE (UNJF); Temp Rating: 140.0 FAHRENHEIT DEGF; Second End Relationship with First End: NOT IDENTICAL; Body Style: STRAIGHT THRU. 11 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 4820-01-640-6689 has DEMIL Code Q. Demilitarization may be required before disposal or transfer to non-military entities.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.