The Valve,safety Relief, cataloged under National Stock Number 4820-01-025-7838, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 22 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-025-7838 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Style Designator | ANGLE |
| Material Document and Classification | AMS 5643 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | QQ-S-763,CLASS 440C FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES FIRST END IN |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Maximum Operating Temp | 275.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | HYDRAULIC FLUID, PETROLEUM BASE SINGLE RESPONSE |
| Thread Class | 3A FIRST END A |
| Material | STEEL BODY |
| Material | STEEL FLOW CONTROL DEVICE |
| Material | PLASTIC POLYAMIDE NYLON SEAT |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) FIRST END |
| Opening Pressure Setting | 3600.0 POUNDS PER SQUARE INCH LBS |
| Valve Discharge Flow Rate | 1.0 GALLONS PER MINUTE |
| 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 |
|---|---|
| P26-771 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-025-7838 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-025-7838: Flow Control Device: POPPET; Connection Style: FLARED (TUBE) FIRST END; Connection Type: THREADED EXTERNAL TUBE FIRST END; Style Designator: ANGLE. 22 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.