The Disk,valve, cataloged under National Stock Number 4820-00-646-9765, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Atwood & Morrill Co., Inc. Dba Weir Valves and Controls Usa. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-646-9765 |
| Primary Part Number | 4577FPC6 |
| Item Name | Disk,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Atwood & Morrill Co., Inc. Dba Weir Valves and Controls Usa |
| Status | ACTIVE |
| Shank Diameter | 2.240 INCHES NOMINAL IN |
| Flange Diameter | 2.240 INCHES NOMINAL IN |
| Style Designator | POPPET |
| Seat Angle | 30.0 DEGREES NOMINAL |
| Material | STEEL CORROSION RESISTING |
| 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 |
|---|---|
| 4577FPC6 PRIMARY | Atwood & Morrill Co., Inc. Dba Weir Valves and Controls Usa (USA) |
| 4588FPC6 PRIMARY | Atwood & Morrill Co., Inc. Dba Weir Valves and Controls Usa (USA) |
| Reference | Meaning |
|---|---|
| 3316287PC6 | 5/2 Secondary reference U.S. Government activity |
| 3316286PC6 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-00-646-9765 is a Disk,valve, manufactured by Atwood & Morrill Co., Inc. Dba Weir Valves and Controls Usa, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-646-9765 has 2 manufacturer part numbers on file: 4577FPC6 (Atwood & Morrill Co., Inc. Dba Weir Valves and Controls Usa), 4588FPC6 (Atwood & Morrill Co., Inc. Dba Weir Valves and Controls Usa).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-225-9501. Verify interchangeability with system specifications before substitution.
Key specifications for 4577FPC6: Shank Diameter: 2.240 INCHES NOMINAL IN; Flange Diameter: 2.240 INCHES NOMINAL IN; Overall Height: 4.770 INCHES NOMINAL IN; Style Designator: POPPET. 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.