The Seat,valve, cataloged under National Stock Number 4820-01-281-1637, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is William E Williams Valve Corp. Government technical data includes 4 specifications, cited from the U.S. Government catalog. The record lists 2 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-281-1637 |
| Primary Part Number | 8427-8-3 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | William E Williams Valve Corp |
| Status | ACTIVE |
| Seal Accommodation Type | GROOVED |
| Style Designator | PLAIN |
| Material | STEEL OVERALL |
| Seating Surface Shape | O-RING |
| 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 |
|---|---|
| 8427-8-3 PRIMARY | William E Williams Valve Corp (USA) |
| LHD8428 ITEM 3 PRIMARY | William E Williams Valve Corp (USA) |
| Reference | Meaning |
|---|---|
| LHD8428 | D/9 Drawing number reference only William E Williams Valve Corp |
NSN 4820-01-281-1637 is a Seat,valve, manufactured by William E Williams Valve Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-281-1637 has 2 manufacturer part numbers on file: 8427-8-3 (William E Williams Valve Corp), LHD8428 ITEM 3 (William E Williams Valve Corp).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-281-2447, 4820-01-281-2494, 5365-01-281-5237. Verify interchangeability with system specifications before substitution.
Key specifications for 8427-8-3: Seal Accommodation Type: GROOVED; Style Designator: PLAIN; End Item Identification: WILLIAMS 8 IN. GATE VALVE,LHD8428 IN; Material: STEEL OVERALL. 4 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.