The Valve,safety Relief, cataloged under National Stock Number 4820-01-420-1900, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 6 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-420-1900 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Style Designator | STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF SEPARABLE SECTIONS. |
| Operating Pressure | 2300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Material | STEEL CORROSION RESISTING BODY |
| Valve Discharge Flow Rate | 12.0 POUNDS PER HOUR 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 |
|---|---|
| 211076731 | 5/9 Secondary reference Naval Sea Systems Command |
| 1703-13 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-420-1900 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-420-1900: Flow Control Device: DISK; Style Designator: STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF SEPARABLE SECTIONS.; Operating Pressure: 2300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS; End Item Identification: SEAWOLF CLASS SSN. 6 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.