The Valve,safety Relief, cataloged under National Stock Number 4820-01-221-4268, 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11 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-221-4268 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Style Designator | ANGLE |
| Material Document and Classification | QQ-S-764 FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Material Document and Classification | QQ-B-637 FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | AMS3651 ASSN STD SINGLE MATERIAL RESPONSE SEAT |
| Operating Pressure | 50.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +20.0 TO 50.0 POUNDS PER SQUARE INCH LBS |
| Material | STEEL COMP 303 FLOW CONTROL DEVICE |
| Material | PLASTIC POLYTETRAFLUOROETHYLENE SEAT |
| Material | COPPER ALLOY 464 BODY |
| Valve Operation Method | MANUAL |
| 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 |
|---|---|
| 280298-03 | 3/2 Design control — primary reference U.S. Government activity |
| 280085 ITEM 3 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-221-4268 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-221-4268: Flow Control Device: POPPET; Style Designator: ANGLE; Material Document and Classification: QQ-S-764 FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE; Material Document and Classification: QQ-B-637 FED SPEC SINGLE MATERIAL RESPONSE BODY. 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.
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.