The Seat,valve, cataloged under National Stock Number 4820-01-134-1331, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is The Walworth Company. Government technical data includes 14 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-134-1331 |
| Primary Part Number | 2620-902X7 PIECE 20 1IN |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | The Walworth Company |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.156 INCHES NOMINAL IN |
| Flange Diameter | 1.563 INCHES NOMINAL IN |
| Thread Length | 0.312 INCHES NOMINAL SINGLE THREADED PORTION IN |
| Style Designator | THREADED FLANGED |
| Material Document and Classification | QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Body Inside Diameter | 0.750 INCHES NOMINAL IN |
| Nominal Thread Size | 1.375 INCHES SINGLE THREADED PORTION IN |
| Under Flange Height | 0.375 INCHES NOMINAL IN |
| Thread Class | 2A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 20 SINGLE THREADED PORTION |
| Material | NICKEL ALLOY OVERALL |
| Seat Angle in Deg | 75.000 NOMINAL |
| Thread Series Designator | UN SINGLE THREADED PORTION |
| Seating Surface Shape | ANGULAR |
| 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 |
|---|---|
| 2620-902X7 PIECE 20 1IN PRIMARY | The Walworth Company (USA) |
| Reference | Meaning |
|---|---|
| 2620-902X7 PIECE 20 1IN | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-134-1331 is a Seat,valve, manufactured by The Walworth Company, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-134-1331 has 1 manufacturer part number on file: 2620-902X7 PIECE 20 1IN (The Walworth Company).
Key specifications for 2620-902X7 PIECE 20 1IN: Flange Seat to Disk End Height: 0.156 INCHES NOMINAL IN; Flange Diameter: 1.563 INCHES NOMINAL IN; Thread Length: 0.312 INCHES NOMINAL SINGLE THREADED PORTION IN; Style Designator: THREADED FLANGED. 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.