The Seat,valve, cataloged under National Stock Number 4820-01-433-7895, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Velan Valve Corp.. Government technical data includes 7 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-433-7895 |
| Primary Part Number | 8541-004-002-S |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Velan Valve Corp. |
| Status | ACTIVE |
| Body Outside Diameter | 3.000 INCHES NOMINAL IN |
| Style Designator | PLAIN |
| Material Document and Classification | ASTM A105 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Body Inside Diameter | 2.500 INCHES NOMINAL IN |
| Material | STEEL BODY |
| Seat Angle in Deg | 30.000 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 |
|---|---|
| 8541-004-002-S PRIMARY | Velan Valve Corp. (USA) |
| 73811-13 ITEM 04 2 1/2IN | Velan Valve Corp. (USA) |
| Reference | Meaning |
|---|---|
| 73811-13 | D/9 Drawing number reference only Velan Valve Corp. |
NSN 4820-01-433-7895 is a Seat,valve, manufactured by Velan Valve Corp., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-433-7895 has 2 manufacturer part numbers on file: 8541-004-002-S (Velan Valve Corp.), 73811-13 ITEM 04 2 1/2IN (Velan Valve Corp.).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-522-6164. Verify interchangeability with system specifications before substitution.
Key specifications for 8541-004-002-S: Overall Height: 0.500 INCHES NOMINAL IN; Body Outside Diameter: 3.000 INCHES NOMINAL IN; Style Designator: PLAIN; Material Document and Classification: ASTM A105 ASSN STD SINGLE MATERIAL RESPONSE BODY. 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.