The Valve,safety Relief, cataloged under National Stock Number 4820-01-028-1538, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 19 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-01-028-1538 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN,OPTIONAL END(PIPE) ALL ENDS |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | ANGLE |
| Material Document and Classification | QQ-S-764,TYPE 303-CANCELED FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Operating Pressure | 250.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.125 INCHES ALL ENDS IN |
| Maximum Operating Temp | 180.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | ANODIZE LOCATION NOT OTHERWISE SPECIFIED |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SINGLE RESPONSE |
| Material | STEEL COMP 303 FLOW CONTROL DEVICE |
| Material | ALUMINUM ALLOY BODY |
| Material | PLASTIC POLYTETRAFLUOROETHYLENE SEAT |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 200.0 POUNDS PER SQUARE INCH LBS |
| Valve Discharge Flow Rate | 2.0 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 |
|---|---|
| 627B4-1-8-3 | 3/9 Design control — primary reference U.S. Government activity |
| 627B4-1-8-3 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-028-1538 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-028-1538: Flow Control Device: POPPET; Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS; Connection Type: THREADED INTERNAL PIPE ALL ENDS; Style Designator: ANGLE. 19 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.