The Disk,valve, cataloged under National Stock Number 4820-01-536-6581, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 10 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-536-6581 |
| Item Name | Disk,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.281 INCHES NOMINAL IN |
| Pressure Rating | 400.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM LBS |
| Temp Rating | 250.0 FAHRENHEIT MAXIMUM DEGF |
| Outside Diameter | 0.938 INCHES NOMINAL IN |
| Style Designator | SWING CHECK |
| Body Inside Diameter | 0.302 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN |
| Inside Diameter | 0.302 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN |
| Under Flange Height | 0.657 INCHES NOMINAL IN |
| Media for Which Designed | WATER OR OIL OR GAS OR STEAM |
| Material | NICKEL ALLOY |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 803-1385721-51-18 | 5/2 Secondary reference U.S. Government activity |
| 1385721 | D/9 Drawing number reference only U.S. Government activity |
| 803-1385721-5X-18 | 3/2 Design control — primary reference U.S. Government activity |
| 803-1385721-52-18 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-536-6581 is a Disk,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-01-580-1459. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-536-6581: Flange Seat to Disk End Height: 0.281 INCHES NOMINAL IN; Pressure Rating: 400.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM LBS; Temp Rating: 250.0 FAHRENHEIT MAXIMUM DEGF; Outside Diameter: 0.938 INCHES NOMINAL IN. 10 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.