The Seat,valve, cataloged under National Stock Number 4820-01-524-1899, 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 7 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-524-1899 |
| Primary Part Number | 506-7503537 8IN PART NO 50 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Body Outside Diameter | 8.687 INCHES NOMINAL IN |
| Style Designator | PLAIN |
| Material Document and Classification | MIL-S-6855 CL. 1 MIL SPEC SINGLE MATERIAL RESPONSE SEAT |
| Body Inside Diameter | 7.890 INCHES NOMINAL IN |
| Material | RUBBER BUNA N SEAT |
| Seat Angle in Deg | 45.000 NOMINAL |
| 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 |
|---|---|
| 506-7503537 8IN PART NO 50 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 4402154 | D/9 Drawing number reference only U.S. Government activity |
| 7503537 | D/9 Drawing number reference only Huntington Ingalls Inc Div Newport News Shipbuilding |
| 506-4402154 8IN PART NO 34 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-524-1899 is a Seat,valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-524-1899 has 1 manufacturer part number on file: 506-7503537 8IN PART NO 50 (Naval Sea Systems Command).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-524-1901. Verify interchangeability with system specifications before substitution.
Key specifications for 506-7503537 8IN PART NO 50: Overall Height: 0.281 INCHES NOMINAL IN; Body Outside Diameter: 8.687 INCHES NOMINAL IN; Style Designator: PLAIN; Material Document and Classification: MIL-S-6855 CL. 1 MIL SPEC SINGLE MATERIAL RESPONSE SEAT. 7 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.