The Valve,safety Relief, cataloged under National Stock Number 4820-01-266-8144, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 9 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-266-8144 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Nominal Pipe Size Accommodated | 1.000 INCHES ALL ENDS IN |
| Connection Style | STREAMLINED WITH ONE BRAZING RING ALL ENDS |
| Connection Type | UNTHREADED INTERNAL PIPE ALL ENDS |
| Style Designator | ANGLE |
| Material | COPPER ALLOY BODY |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Opening Pressure Setting | 140.0 POUNDS PER SQUARE INCH LBS |
| 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 |
|---|---|
| 59610-8 AND 59610-TAB | 3/2 Design control — primary reference U.S. Government activity |
| 59610-TAB | D/9 Drawing number reference only U.S. Government activity |
NSN 4820-01-266-8144 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4820-01-316-9673, 4730-01-318-4230. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-266-8144: Flow Control Device: POPPET; Nominal Pipe Size Accommodated: 1.000 INCHES ALL ENDS IN; Connection Style: STREAMLINED WITH ONE BRAZING RING ALL ENDS; Connection Type: UNTHREADED INTERNAL PIPE ALL ENDS. 9 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.