The Valve,safety Relief, cataloged under National Stock Number 4820-00-858-0502, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 21 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-858-0502 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | FLARELESS (TUBE) SECOND END |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED EXTERNAL TUBE SECOND END |
| Style Designator | CROSS |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES SECOND END IN |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES FIRST END IN |
| Operating Pressure | 16.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.750 INCHES SECOND END IN |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Seat Angle | 24.0 DEGREES FIRST END |
| Seat Angle | 24.0 DEGREES SECOND END |
| Maximum Operating Temp | 65.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Thread Class | 3A FIRST END A |
| Thread Class | 3A SECOND END A |
| Thread Quantity Per Inch | 12 THIRD END |
| Thread Series Designator | UN THIRD END |
| Opening Pressure Setting | 12.0 POUNDS PER SQUARE INCH LBS |
| 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 |
|---|---|
| 219815 | 3/2 Design control — primary reference U.S. Government activity |
| 668276-11 | 7/2 Vendor item drawing reference U.S. Government activity |
NSN 4820-00-858-0502 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-858-0502: Flow Control Device: POPPET; Connection Style: FLARELESS (TUBE) SECOND END; Connection Type: THREADED EXTERNAL TUBE FIRST END; Connection Type: THREADED EXTERNAL TUBE SECOND END. 21 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.