The Valve,safety Relief, cataloged under National Stock Number 4820-01-172-6253, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 8 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-172-6253 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | STEM |
| Criticality Code Justification | ZZZY |
| Bonnet Type | INSIDE SPRING |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | BOLTED |
| Material | COPPER ALLOY 922 OVERALL |
| Valve Operation Method | AUTOMATIC |
| Reference Number Differentiating Characteristics | MATERIAL WILL BE IN ACCORDANCE WITH SHIPS PARTS CONTROL CENTER ACTIVITY HX QUALITY CONTROL,MANUFACTURING AND TESTING SPECIFICATIONS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL F — Mutilate — Cut |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | C |
| Reference | Meaning |
|---|---|
| 20195 | 5/1 Secondary reference Emerson Automation Solutions Final Control Us Lp Div Navy Product Team |
| 20195 | 5/1 Secondary reference General Nucleonics, Inc. Dba General Nucleonics Inc |
| 2019500C51M | 3/1 Design control — primary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-172-6253 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-172-6253: Flow Control Device: STEM; Criticality Code Justification: ZZZY; Bonnet Type: INSIDE SPRING; Disk Loading Method: SPRING. 8 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.
NSN 4820-01-172-6253 has DEMIL Code F. Demilitarization may be required before disposal or transfer to non-military entities.
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.