The Valve,butterfly, cataloged under National Stock Number 4820-01-309-9934, 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 11 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-309-9934 |
| Primary Part Number | 920L181 |
| Item Name | Valve,butterfly |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Dover Resources, Inc. Div Norriseal |
| Status | ACTIVE |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | ASTM A395 ALLOY 60-40-18 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | ASTM B148 ALLOY 958 ASSN STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Operating Pressure | 285.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 10.000 INCHES IN |
| Mounting Facility | WAFER |
| Material | RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR PACKING |
| Material | STEEL CORROSION RESISTING STEM |
| Material | COPPER ALLOY 958 FLOW CONTROL DEVICE |
| Material | IRON CAST UNS F32800 BODY |
| Valve Operation Method | MANUAL |
| 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 |
|---|---|
| 920L181 | Dover Resources, Inc. Div Norriseal (USA) |
| Reference | Meaning |
|---|---|
| R285A-147AA-2MM 10INCH | 3/9 Design control — primary reference U.S. Government activity |
| 920L181 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-309-9934 is a Valve,butterfly, manufactured by Dover Resources, Inc. Div Norriseal, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-309-9934 has 1 manufacturer part number on file: 920L181 (Dover Resources, Inc. Div Norriseal).
Key specifications for 920L181: Style Designator: STRAIGHT THRU; Material Document and Classification: ASTM A395 ALLOY 60-40-18 ASSN STD SINGLE MATERIAL RESPONSE BODY; Material Document and Classification: ASTM B148 ALLOY 958 ASSN STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE; Operating Pressure: 285.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS. 11 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.