The Valve,safety Relief, cataloged under National Stock Number 4820-00-656-7170, 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6 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-00-656-7170 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Style Designator | STRAIGHT THRU |
| Disk Loading Method | SPRING |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SINGLE RESPONSE |
| Material | ALUMINUM ALLOY 2024 OVERALL |
| 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 |
|---|---|
| 373806 | 3/2 Design control — primary reference U.S. Government activity |
| 373806 | 5/9 Secondary reference Alliedsignal Inc Dba Allied-Signal Aerospace Co |
NSN 4820-00-656-7170 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-656-7170: Flow Control Device: POPPET; Style Designator: STRAIGHT THRU; Disk Loading Method: SPRING; Media for Which Designed: FUEL/OIL, HYDROCARBON SINGLE RESPONSE. 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.