The Seat,valve, cataloged under National Stock Number 4820-01-458-3799, 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 13 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 6 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-458-3799 |
| Primary Part Number | 845-769815-21-018 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.188 INCHES NOMINAL IN |
| Flange Diameter | 0.930 INCHES NOMINAL IN |
| Thread Length | 0.078 INCHES MINIMUM AND 0.095 INCHES MAXIMUM SINGLE THREADED PORTION IN |
| Style Designator | FAUCET |
| Material Document and Classification | MIL-T-9047 6AL-4V MIL SPEC SINGLE MATERIAL RESPONSE OVERALL V |
| Body Inside Diameter | 0.496 INCHES MINIMUM AND 0.504 INCHES MAXIMUM IN |
| Nominal Thread Size | 0.750 INCHES SINGLE THREADED PORTION IN |
| Surface Treatment | ANODIZE OVERALL |
| Under Flange Height | 0.328 INCHES NOMINAL IN |
| Thread Class | 3A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 15 SINGLE THREADED PORTION |
| Material | TITANIUM ALLOY OVERALL |
| Seating Surface Shape | FLAT |
| 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 |
|---|---|
| 845-769815-21-018 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 845-7069815-21- | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| 845-7069815 | D/9 Drawing number reference only Naval Sea Systems Command |
NSN 4820-01-458-3799 is a Seat,valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-458-3799 has 1 manufacturer part number on file: 845-769815-21-018 (Naval Sea Systems Command).
6 possible matches (shared part number, not a government interchangeability claim): 4820-01-458-3801, 4820-01-458-3803, 4820-01-460-8426. Verify interchangeability with system specifications before substitution.
Key specifications for 845-769815-21-018: Flange Seat to Disk End Height: 0.188 INCHES NOMINAL IN; Flange Diameter: 0.930 INCHES NOMINAL IN; Thread Length: 0.078 INCHES MINIMUM AND 0.095 INCHES MAXIMUM SINGLE THREADED PORTION IN; Style Designator: FAUCET. 13 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.