The Valve,safety Relief, cataloged under National Stock Number 4820-01-181-8519, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 14 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-181-8519 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN (TUBE) SECOND END |
| Connection Style | SWIVEL NUT,FLARELESS(TUBE) FIRST END |
| Connection Type | UNTHREADED EXTERNAL TUBE SECOND END |
| Connection Type | THREADED INTERNAL TUBE FIRST END |
| Style Designator | ANGLE |
| Nominal Outside Diameter Tube Accommodated | 0.750 INCHES SECOND END IN |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 1.250 INCHES FIRST END IN |
| Thread Class | 2B FIRST END |
| Material | STEEL BODY |
| Thread Series Designator | UNF FIRST END |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 023604 | 3/9 Design control — primary reference U.S. Government activity |
NSN 4820-01-181-8519 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5935-01-541-9366. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-181-8519: Flow Control Device: DISK; Connection Style: PLAIN (TUBE) SECOND END; Connection Style: SWIVEL NUT,FLARELESS(TUBE) FIRST END; Connection Type: UNTHREADED EXTERNAL TUBE SECOND END. 14 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.
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.