The Disk,valve, cataloged under National Stock Number 4820-01-310-6617, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Dover Resources, Inc. Div Norriseal. Government technical data includes 3 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-310-6617 |
| Primary Part Number | 920-170 REF-2 |
| Item Name | Disk,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Dover Resources, Inc. Div Norriseal |
| Status | ACTIVE |
| Pressure Rating | 150.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS |
| Style Designator | BUTTERFLY |
| Material | ALUMINUM AND COPPER 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 |
|---|---|
| 920-170 REF-2 PRIMARY | Dover Resources, Inc. Div Norriseal (USA) |
| 51310A391 8IN PRIMARY | Dover Resources, Inc. Div Norriseal (USA) |
| Reference | Meaning |
|---|---|
| 51310A391 8IN | 5/9 Secondary reference U.S. Government activity |
| 920-170 REF-2 | 5/9 Secondary reference U.S. Government activity |
| 51310A391 | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
| 920-170 | D/9 Drawing number reference only U.S. Government activity |
NSN 4820-01-310-6617 is a Disk,valve, manufactured by Dover Resources, Inc. Div Norriseal, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-310-6617 has 2 manufacturer part numbers on file: 920-170 REF-2 (Dover Resources, Inc. Div Norriseal), 51310A391 8IN (Dover Resources, Inc. Div Norriseal).
2 possible matches (shared part number, not a government interchangeability claim): 5995-01-357-0722, 4220-01-733-4657. Verify interchangeability with system specifications before substitution.
Key specifications for 920-170 REF-2: Pressure Rating: 150.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS; Style Designator: BUTTERFLY; Material: ALUMINUM AND COPPER 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.