The Disk,valve, cataloged under National Stock Number 4820-01-442-0749, 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 3 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-442-0749 |
| Primary Part Number | 218020212 |
| Item Name | Disk,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Outside Diameter | 4.951 INCHES NOMINAL IN |
| Inside Diameter | 4.200 INCHES NOMINAL IN |
| 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 |
| Part Number | Manufacturer |
|---|---|
| 801-6556655 FIND A8 | Naval Sea Systems Command (USA) |
| 801-6556655-A8 | Naval Sea Systems Command (USA) |
| 218020212 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 2643-1002-63 FN A8 | 5/2 Secondary reference U.S. Government activity |
| 6556655 | D/9 Drawing number reference only Naval Sea Systems Command |
| 2643-1002-63 | D/9 Drawing number reference only U.S. Government activity |
NSN 4820-01-442-0749 is a Disk,valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-442-0749 has 3 manufacturer part numbers on file: 801-6556655 FIND A8 (Naval Sea Systems Command), 801-6556655-A8 (Naval Sea Systems Command), 218020212 (Naval Sea Systems Command).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-442-0793. Verify interchangeability with system specifications before substitution.
Key specifications for 218020212: Overall Height: 9.344 INCHES NOMINAL IN; Outside Diameter: 4.951 INCHES NOMINAL IN; Inside Diameter: 4.200 INCHES NOMINAL IN; End Item Identification: SEAWOLF CLASS SSN. 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.