The Valve,safety Relief, cataloged under National Stock Number 4820-00-202-8221, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 50 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-202-8221 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Nominal Pipe Size Accommodated | 0.375 INCHES ALL ENDS IN |
| Connection Style | PLAIN (PIPE) ALL ENDS |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Style Designator | ANGLE |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.375 INCHES ALL ENDS IN |
| Disk Loading Method | SPRING |
| Thread Quantity Per Inch | 18 FIRST END |
| Material | COPPER ALLOY BODY |
| Material | STEEL STEM |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 20.0 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 |
|---|---|
| CV22S47-88ALT6PC501T0506 | 3/2 Design control — primary reference U.S. Government activity |
| CL55S47-89ALT6PC501T0506 | 3/2 Design control — primary reference U.S. Government activity |
| D15-649-501T506 | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
| CVL48S5501-478939PC173 | 3/2 Design control — primary reference U.S. Government activity |
| D15-675APC501T0506 | 5/9 Secondary reference U.S. Government activity |
| D15-675BPC501T0506 | 3/2 Design control — primary reference U.S. Government activity |
| CVL48S5501-478982ALT3PC162 | 3/2 Design control — primary reference U.S. Government activity |
| D15-675MPC501T0506-508 | 3/2 Design control — primary reference U.S. Government activity |
| D15-675BPC501T0506 | 5/9 Secondary reference Westinghouse Electric Corp |
| D15-675MPC501T0506-508 | 5/9 Secondary reference U.S. Government activity |
| DD445S4601-250PC501T0506 | 3/2 Design control — primary reference U.S. Government activity |
| CA122S5505-179253PC501T0506 | 3/2 Design control — primary reference U.S. Government activity |
| CL55S47-81ALT6PC501T0506 | 3/2 Design control — primary reference U.S. Government activity |
| D15-649BPC501T0506 | 5/9 Secondary reference Westinghouse Electric Corp |
| D15-649-501T0506-512 | 3/2 Design control — primary reference U.S. Government activity |
| C2555-1DPC373 | 5/9 Secondary reference Ex-Cell-O Corp Machine Tool Products Div |
| D15-653BPC501T0506 | 5/9 Secondary reference Westinghouse Electric Corp |
| D15-683APC501T0506-508 | 5/9 Secondary reference Westinghouse Electric Corp |
| D15-649-501-506 | 5/9 Secondary reference Westinghouse Electric Corp |
| D15-649BPC50T05 06 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-00-202-8221 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-202-8221: Flow Control Device: POPPET; Nominal Pipe Size Accommodated: 0.375 INCHES ALL ENDS IN; Connection Style: PLAIN (PIPE) ALL ENDS; Connection Type: THREADED EXTERNAL PIPE ALL ENDS. 15 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.