The Seat,valve, cataloged under National Stock Number 4820-00-973-3777, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 14 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-973-3777 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.562 INCHES NOMINAL IN |
| Flange Diameter | 2.745 INCHES MINIMUM AND 2.746 INCHES MAXIMUM IN |
| Body Outside Diameter | 2.502 INCHES NOMINAL IN |
| Seal Accommodation Type | GROOVED |
| Taper Minor Diameter | 1.562 INCHES NOMINAL IN |
| Style Designator | PLAIN FLANGED |
| Material Document and Classification | MIL-R-17131,TYPE MIL-RCOCR-A MIL SPEC SINGLE MATERIAL RESPONSE FACE |
| Material Document and Classification | ASTM A182,GRADE F21 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Body Inside Diameter | 1.562 INCHES NOMINAL IN |
| Taper Length | 0.812 INCHES NOMINAL IN |
| Under Flange Height | 0.936 INCHES NOMINAL IN |
| Material | STEEL BODY |
| Material | COBALT ALLOY FACE |
| Seating Surface Shape | RADIAL |
| 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 |
|---|---|
| NP417PC30 | 3/9 Design control — primary reference U.S. Government activity |
| NL667-1 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-973-3777 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-973-3777: Flange Seat to Disk End Height: 0.562 INCHES NOMINAL IN; Flange Diameter: 2.745 INCHES MINIMUM AND 2.746 INCHES MAXIMUM IN; Body Outside Diameter: 2.502 INCHES NOMINAL IN; Seal Accommodation Type: GROOVED. 14 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.