The Seat,valve, cataloged under National Stock Number 4820-01-446-1998, 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 14 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-446-1998 |
| Primary Part Number | 803-6397434-X21XXX-022 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.122 INCHES NOMINAL IN |
| Flange Diameter | 0.930 INCHES NOMINAL IN |
| Thread Length | 0.094 INCHES MAXIMUM SINGLE THREADED PORTION IN |
| Style Designator | THREADED FLANGED |
| Material Document and Classification | MIL-C-24252 COMP 1,COND A MIL SPEC ALL MATERIAL RESPONSES OVERALL |
| Body Inside Diameter | 0.471 INCHES NOMINAL IN |
| Nominal Thread Size | 0.766 INCHES SINGLE THREADED PORTION IN |
| Under Flange Height | 0.316 INCHES NOMINAL IN |
| Thread Class | 3A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 24 SINGLE THREADED PORTION |
| Material | COBALT OVERALL |
| Seat Angle in Deg | 45.000 NOMINAL |
| Thread Series Designator | UNS SINGLE THREADED PORTION |
| Seating Surface Shape | ANGULAR |
| 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 |
|---|---|
| 803-6397434-X21XXX-022 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 6397434 | D/9 Drawing number reference only Naval Sea Systems Command |
NSN 4820-01-446-1998 is a Seat,valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-446-1998 has 1 manufacturer part number on file: 803-6397434-X21XXX-022 (Naval Sea Systems Command).
Key specifications for 803-6397434-X21XXX-022: Flange Seat to Disk End Height: 0.122 INCHES NOMINAL IN; Flange Diameter: 0.930 INCHES NOMINAL IN; Thread Length: 0.094 INCHES MAXIMUM SINGLE THREADED PORTION IN; Style Designator: THREADED FLANGED. 14 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.