The Valve,safety Relief, cataloged under National Stock Number 4820-00-202-5501, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 25 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-202-5501 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Nominal Pipe Size Accommodated | 2.000 INCHES SECOND END IN |
| Nominal Pipe Size Accommodated | 2.000 INCHES FIRST END IN |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | ANGLE |
| Material Document and Classification | QQ-C-390,ALLOYB5/D/ FED SPEC SINGLE MATERIAL RESPONSE SEAT |
| Material Document and Classification | QQ-C-390,ALLOYB5/D FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | QQ-C-390,ALLOYB5/D/ FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Features Provided | VALVE STEM LOCK SHIELD |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 2.000 INCHES SECOND END IN |
| Nominal Thread Size | 2.000 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY FLOW CONTROL DEVICE |
| Material | STEEL STEM |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 15.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATIC OR 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 |
|---|---|
| FIG2501 | 3/1 Design control — primary reference Crane Co Div Valve Div |
NSN 4820-00-202-5501 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-00-202-5503. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-202-5501: Flow Control Device: DISK; Nominal Pipe Size Accommodated: 2.000 INCHES SECOND END IN; Nominal Pipe Size Accommodated: 2.000 INCHES FIRST END IN; Connection Style: PLAIN,OPTIONAL END(PIPE) FIRST END. 25 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.