The Valve,safety Relief, cataloged under National Stock Number 4820-01-356-2633, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Hardigg Industries, Llc Div Hardigg Cases. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 — Valves, Nonpowered (FSG 48) |
| Manufacturers | Abp Technologies Ltd Div Eod Explosive Ordinance (CAGE U4866); Hardigg Industries, Llc Div Hardigg Cases (CAGE 11214) |
| Parameter | Value |
|---|---|
| NSN | 4820-01-356-2633 |
| Primary Part Number | P21-531 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Hardigg Industries, Llc Div Hardigg Cases |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 3368-070 | Abp Technologies Ltd Div Eod Explosive Ordinance (GBR) |
| 9955-201 ITEM 14 | Hardigg Industries, Llc Div Hardigg Cases (USA) |
| P21-531 PRIMARY | Hardigg Industries, Llc Div Hardigg Cases (USA) |
| Reference | Meaning |
|---|---|
| 9955-201 | D/9 Drawing number reference only Hardigg Industries, Llc Div Hardigg Cases |
NSN 4820-01-356-2633 is a Valve,safety Relief, manufactured by Hardigg Industries, Llc Div Hardigg Cases, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-356-2633 has 3 manufacturer part numbers on file: 3368-070 (Abp Technologies Ltd Div Eod Explosive Ordinance), 9955-201 ITEM 14 (Hardigg Industries, Llc Div Hardigg Cases), P21-531 (Hardigg Industries, Llc Div Hardigg Cases).
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 4820-01-356-2633 has DEMIL Code Q. 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.