The Valve,pilot,stem, cataloged under National Stock Number 4820-01-221-5651, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Westinghouse Electric Corp. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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.
| Item Name | Valve,pilot,stem |
| FSC / FSG | 4820 — Valves, Nonpowered (FSG 48) |
| Manufacturers | Westinghouse Electric Corp (CAGE 79500) |
| Parameter | Value |
|---|---|
| NSN | 4820-01-221-5651 |
| Primary Part Number | 667J655 PIECE 30 |
| Item Name | Valve,pilot,stem |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Westinghouse Electric Corp |
| 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 |
| Part Number | Manufacturer |
|---|---|
| 667J655 PIECE 30 | Westinghouse Electric Corp (USA) |
| Reference | Meaning |
|---|---|
| S-957 PIECE 3 | 5/9 Secondary reference U.S. Government activity |
| NL-578-1 | 3/9 Design control — primary reference U.S. Government activity |
| 366B433 | D/9 Drawing number reference only U.S. Government activity |
| 667J655 | D/9 Drawing number reference only Westinghouse Electric Corp |
| 366B433 ITEM 296 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-221-5651 is a Valve,pilot,stem, manufactured by Westinghouse Electric Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-221-5651 has 1 manufacturer part number on file: 667J655 PIECE 30 (Westinghouse Electric Corp).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-221-7496. 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.
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.