The Cap,valve, cataloged under National Stock Number 4820-01-278-3640, 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 6 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-278-3640 |
| Primary Part Number | 8521-506-031 |
| Item Name | Cap,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Velan Valve Corp. |
| Status | ACTIVE |
| Valve Type for Which Designed | GLOBE |
| Valve Model Number for Which Designed | 2 2/1 IN. IN |
| Material Document and Classification | ASTM A216,COMP D ASSN STD SINGLE MATERIAL RESPONSE |
| Valve Size for Which Designed | 2.500 INCHES IN |
| Material | STEEL |
| Attachment Method | BOLTS |
| 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 |
|---|---|
| 8521-506-031 PRIMARY | Velan Valve Corp. (USA) |
| 73423-32 PC2 2-1/2IN | Velan Valve Corp. (USA) |
| 73423-32 ITEM 2 | Velan Valve Corp. (USA) |
| Reference | Meaning |
|---|---|
| 73423-32 | D/9 Drawing number reference only Velan Valve Corp. |
| 8521-006-4-031 | 5/9 Secondary reference Velan Valve Corp. |
NSN 4820-01-278-3640 is a Cap,valve, manufactured by Velan Valve Corp., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-278-3640 has 3 manufacturer part numbers on file: 8521-506-031 (Velan Valve Corp.), 73423-32 PC2 2-1/2IN (Velan Valve Corp.), 73423-32 ITEM 2 (Velan Valve Corp.).
4 possible matches (shared part number, not a government interchangeability claim): 4820-01-394-8145, 4820-01-431-9220, 4820-01-462-8634. Verify interchangeability with system specifications before substitution.
Key specifications for 8521-506-031: Valve Type for Which Designed: GLOBE; Valve Model Number for Which Designed: 2 2/1 IN. IN; Material Document and Classification: ASTM A216,COMP D ASSN STD SINGLE MATERIAL RESPONSE; Valve Size for Which Designed: 2.500 INCHES IN. 6 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.