The Seat,valve, cataloged under National Stock Number 4820-01-258-9400, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 5 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-258-9400 |
| Primary Part Number | 128HM10501-11 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Body Outside Diameter | 1.118 INCHES NOMINAL IN |
| Style Designator | PLAIN |
| Body Inside Diameter | 0.625 INCHES NOMINAL IN |
| Material | PLASTIC VINYLIDENE FLUORIDE OVERALL |
| Seating Surface Shape | FLAT |
| 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 |
|---|---|
| 128HM10501 | Northrop Grumman Systems Corporation (USA) |
| 128HM10501-11 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| 128HM10501-11 | 5/9 Secondary reference Northrop Grumman Systems Corporation |
| 128HM10501 | 5/9 Secondary reference Northrop Grumman Systems Corporation |
NSN 4820-01-258-9400 is a Seat,valve, manufactured by Northrop Grumman Systems Corporation, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-258-9400 has 2 manufacturer part numbers on file: 128HM10501 (Northrop Grumman Systems Corporation), 128HM10501-11 (Northrop Grumman Systems Corporation).
Key specifications for 128HM10501-11: Overall Height: 0.062 INCHES NOMINAL IN; Body Outside Diameter: 1.118 INCHES NOMINAL IN; Style Designator: PLAIN; Body Inside Diameter: 0.625 INCHES NOMINAL IN. 5 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.