The Seat,valve, cataloged under National Stock Number 4820-01-337-4004, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 5 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. 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 | 4820-01-337-4004 |
| Primary Part Number | 211056675 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Body Outside Diameter | 1.059 INCHES MINIMUM AND 1.060 INCHES MAXIMUM IN |
| Style Designator | PLAIN |
| Body Inside Diameter | 0.967 INCHES MINIMUM AND 0.971 INCHES MAXIMUM IN |
| Material | PLASTIC POLYAMIDE NYLON 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 |
|---|---|
| 801-6408783 FIND 11 | Naval Sea Systems Command (USA) |
| 211056675 PRIMARY | Naval Sea Systems Command (USA) |
NSN 4820-01-337-4004 is a Seat,valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-337-4004 has 2 manufacturer part numbers on file: 801-6408783 FIND 11 (Naval Sea Systems Command), 211056675 (Naval Sea Systems Command).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-535-7845, 4820-01-548-1565, 4820-01-655-5701. Verify interchangeability with system specifications before substitution.
Key specifications for 211056675: Overall Height: 0.250 INCHES NOMINAL IN; Body Outside Diameter: 1.059 INCHES MINIMUM AND 1.060 INCHES MAXIMUM IN; Style Designator: PLAIN; Body Inside Diameter: 0.967 INCHES MINIMUM AND 0.971 INCHES MAXIMUM IN. 5 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.