The Diaphragm,valve,flat, cataloged under National Stock Number 4820-01-431-6670, 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 11 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-431-6670 |
| Primary Part Number | 6983468-PIECE 20 |
| Item Name | Diaphragm,valve,flat |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Pressure Rating | 450.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS |
| Temp Rating | 165.0 FAHRENHEIT MAXIMUM DEGF |
| Outside Diameter | 3.200 INCHES NOMINAL IN |
| Style Designator | FLAT |
| Material Thickness | 0.035 INCHES MINIMUM AND 0.055 INCHES MAXIMUM IN |
| Bolt Hole Quantity | 8 |
| Bolt Circle Diameter | 2.800 INCHES NOMINAL IN |
| Center Hole Diameter | 0.320 INCHES MINIMUM AND 0.360 INCHES MAXIMUM IN |
| Media for Which Designed | WATER, SALT |
| Material | PLASTIC POLYAMIDE NYLON |
| Hole Diameter | 0.260 INCHES MINIMUM AND 0.300 INCHES MAXIMUM IN |
| 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 |
|---|---|
| 6983468-PIECE 20 PRIMARY | Naval Sea Systems Command (USA) |
| 803-6983468-PC020 | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 803-6983468 | D/9 Drawing number reference only Naval Sea Systems Command |
NSN 4820-01-431-6670 is a Diaphragm,valve,flat, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-431-6670 has 2 manufacturer part numbers on file: 6983468-PIECE 20 (Naval Sea Systems Command), 803-6983468-PC020 (Naval Sea Systems Command).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-431-9091, 4820-01-431-9094, 4820-01-431-9193. Verify interchangeability with system specifications before substitution.
Key specifications for 6983468-PIECE 20: Pressure Rating: 450.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS; Temp Rating: 165.0 FAHRENHEIT MAXIMUM DEGF; Outside Diameter: 3.200 INCHES NOMINAL IN; Style Designator: FLAT. 11 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.