The Piston,valve, cataloged under National Stock Number 4820-01-421-9641, 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Supply Class 4820 (Valves, Nonpowered) of the Valves group. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-421-9641 |
| Item Name | Piston,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| 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 |
|---|---|
| V3E10064 ITEM 13 | 5/2 Secondary reference U.S. Government activity |
| V2D11484-4MF | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-421-9641 is a Piston,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-01-554-2779. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-421-9641: End Item Identification: SEAWOLF CLASS SSN. 0 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.