The Valve,safety Relief, cataloged under National Stock Number 4820-01-301-0341, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 17 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-301-0341 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN,OPTIONAL END(PIPE) SECOND END |
| Connection Style | PLAIN (PIPE) FIRST END |
| Connection Type | THREADED INTERNAL PIPE SECOND END |
| Connection Type | THREADED EXTERNAL PIPE FIRST END |
| Style Designator | ANGLE |
| Adjustable Pressure Range | +5000.0 TO 6000.0 POUNDS PER SQUARE INCH LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.250 INCHES FIRST END IN |
| Nominal Thread Size | 0.250 INCHES SECOND END IN |
| Disk Loading Method | SPRING |
| Material | STEEL COMP 316 BODY |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT FIRST END |
| Valve Operation Method | AUTOMATIC |
| Reference Number Differentiating Characteristics | CLEANING IN ACCORDANCE WITH MIL-C-52211 FOR OXYGEN SERVICE |
| 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 |
|---|---|
| SS-4R3A5-C1 | 5/9 Secondary reference Nupro Co |
| 1551AS140 | D/9 Drawing number reference only Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
| SS-4R3A5-C1 | 5/1 Secondary reference Swagelok Co |
| 1551AS140-2 | 3/1 Design control — primary reference Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
NSN 4820-01-301-0341 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-01-311-7374. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-301-0341: Flow Control Device: POPPET; Connection Style: PLAIN,OPTIONAL END(PIPE) SECOND END; Connection Style: PLAIN (PIPE) FIRST END; Connection Type: THREADED INTERNAL PIPE SECOND END. 17 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.