The Disk,valve, cataloged under National Stock Number 4820-01-169-1977, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Hunt Valve Company, Inc.. Government technical data includes 3 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-169-1977 |
| Primary Part Number | A49531-2MFD |
| Item Name | Disk,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Hunt Valve Company, Inc. |
| Status | ACTIVE |
| Outside Diameter | 4.370 INCHES NOMINAL IN |
| Inside Diameter | 4.000 INCHES NOMINAL IN |
| Material | NICKEL ALLOY |
| 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 |
|---|---|
| A49531-2MFD PRIMARY | Hunt Valve Company, Inc. (USA) |
| A49531-2 | Hunt Valve Company, Inc. (USA) |
| D49918 ITEM 5 | Hunt Valve Company, Inc. (USA) |
| Reference | Meaning |
|---|---|
| D49918 | D/9 Drawing number reference only Hunt Valve Company Inc Dba Union Flonetics |
| D49918 ITEM 5 | 5/9 Secondary reference Hunt Valve Company Inc Dba Union Flonetics |
| A49531-2 | 5/9 Secondary reference Hunt Valve Company Inc Dba Union Flonetics |
| A49531-2MFD | 3/9 Design control — primary reference Hunt Valve Company Inc Dba Union Flonetics |
NSN 4820-01-169-1977 is a Disk,valve, manufactured by Hunt Valve Company, Inc., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-169-1977 has 3 manufacturer part numbers on file: A49531-2MFD (Hunt Valve Company, Inc.), A49531-2 (Hunt Valve Company, Inc.), D49918 ITEM 5 (Hunt Valve Company, Inc.).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-171-4393, 4820-01-195-8424, 4820-01-316-4569. Verify interchangeability with system specifications before substitution.
Key specifications for A49531-2MFD: Overall Height: 3.930 INCHES NOMINAL IN; Outside Diameter: 4.370 INCHES NOMINAL IN; Inside Diameter: 4.000 INCHES NOMINAL IN; Material: NICKEL ALLOY. 3 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.