The Head,safety,pressure Relief, cataloged under National Stock Number 4820-01-256-0289, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Item Name | Head,safety,pressure Relief |
| FSC / FSG | 4820 — Valves, Nonpowered (FSG 48) |
| Parameter | Value |
|---|---|
| NSN | 4820-01-256-0289 |
| Item Name | Head,safety,pressure Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL F — Mutilate — Cut |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | C |
| Reference | Meaning |
|---|---|
| D4020 | 5/1 Secondary reference Fike Corporation |
| MRK-2"-600LBANSI-ASSYGI-304SST | 3/1 Design control — primary reference Fike Corporation |
NSN 4820-01-256-0289 is a Head,safety,pressure Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4820-01-256-0844, 4820-01-256-9880. Verify interchangeability with system specifications before substitution.
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 4820-01-256-0289 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.