The Seat,valve, cataloged under National Stock Number 4820-00-956-8628, 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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.
| Parameter | Value |
|---|---|
| NSN | 4820-00-956-8628 |
| Primary Part Number | HBHSP1516 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.281 INCHES NOMINAL IN |
| Flange Diameter | 5.875 INCHES NOMINAL IN |
| Thread Length | 0.562 INCHES NOMINAL SINGLE THREADED PORTION IN |
| Style Designator | THREADED FLANGED |
| Material Document and Classification | QQ-N-288 FED STD SINGLE MATERIAL RESPONSE OVERALL |
| Body Inside Diameter | 4.938 INCHES NOMINAL IN |
| Nominal Thread Size | 5.562 INCHES SINGLE THREADED PORTION IN |
| Under Flange Height | 0.562 INCHES NOMINAL IN |
| Thread Class | 3A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 12 SINGLE THREADED PORTION |
| Material | NICKEL ALLOY OVERALL |
| Thread Series Designator | UNS SINGLE THREADED PORTION |
| 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 |
|---|---|
| HBHSP1516 | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 803-1385637-05X-08 | 3/2 Design control — primary reference U.S. Government activity |
| 5000S4824-1385637-8-5IN | 5/2 Secondary reference U.S. Government activity |
| 810-1385637-5-08 | 5/9 Secondary reference Naval Sea Systems Command |
| 803-1385637-05X | 5/9 Secondary reference U.S. Government activity |
| 810-1385637PIECE8-5INCH | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-956-8628 is a Seat,valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-956-8628 has 1 manufacturer part number on file: HBHSP1516 (Naval Sea Systems Command).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-145-4669. Verify interchangeability with system specifications before substitution.
Key specifications for HBHSP1516: Flange Seat to Disk End Height: 0.281 INCHES NOMINAL IN; Flange Diameter: 5.875 INCHES NOMINAL IN; Thread Length: 0.562 INCHES NOMINAL SINGLE THREADED PORTION IN; Style Designator: THREADED FLANGED. 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.