The Disk,valve, cataloged under National Stock Number 4820-00-978-1956, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 3 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-978-1956 |
| Item Name | Disk,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Outside Diameter | 0.497 INCHES MINIMUM AND 0.503 INCHES MAXIMUM IN |
| Style Designator | SOLID |
| Material | RUBBER CHLOROPRENE CLASS CR |
| 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 |
|---|---|
| D-2047 | 3/9 Design control — primary reference White Consolidated Industries Inc Mcalear Controls R-P and C Valve Div |
NSN 4820-00-978-1956 is a Disk,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4510-01-197-1988. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-978-1956: Overall Height: 0.250 INCHES NOMINAL IN; Outside Diameter: 0.497 INCHES MINIMUM AND 0.503 INCHES MAXIMUM IN; Style Designator: SOLID; Material: RUBBER CHLOROPRENE CLASS CR. 3 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.