The Valve,relief,pressure and Temper, cataloged under National Stock Number 4820-01-668-5866, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 12 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-668-5866 |
| Item Name | Valve,relief,pressure and Temper |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| First End Thread Series Designator | NPT |
| Temp Rating | -320.0 FAHRENHEIT AND 165.0 FAHRENHEIT DEGF |
| Second End Relationship with First End | NOT IDENTICAL |
| Body Style | STRAIGHT THRU |
| Material Document and Classification | ASTM B16-60, 1/2H ASSN STD SINGLE MATERIAL RESPONSE BODY |
| End Connection Quantity | 2 |
| Opening Pressure Setting | ERR-060 |
| First End Connection Type | THREADED EXTERNAL PIPE |
| First End Nominal Pipe Size Accommodated | 0.25 INCHES IN |
| Material | COPPER ALLOY 360 BODY |
| Media for Which Designed | OXYGEN, LIQUID |
| Second End Connection Type | THREADED INTERNAL PIPE |
| 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 |
|---|---|
| CRV-250B-K-400 | 3/9 Design control — primary reference U.S. Government activity |
NSN 4820-01-668-5866 is a Valve,relief,pressure and Temper, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-668-5866: First End Thread Series Designator: NPT; Temp Rating: -320.0 FAHRENHEIT AND 165.0 FAHRENHEIT DEGF; Second End Relationship with First End: NOT IDENTICAL; Body Style: STRAIGHT THRU. 12 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.