The Stem,fluid Valve, cataloged under National Stock Number 4820-01-355-3378, 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-355-3378 |
| Primary Part Number | 51740B637 |
| Item Name | Stem,fluid Valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Dover Resources, Inc. Div Norriseal |
| Status | ACTIVE |
| Valve Type for Which Designed | BUTTERFLY |
| Stem Actuating End Type | THREADED EXTERNALLY |
| 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 |
|---|---|
| 51740B637 PRIMARY | Dover Resources, Inc. Div Norriseal (USA) |
| 920-220REF 3 PRIMARY | Dover Resources, Inc. Div Norriseal (USA) |
| Reference | Meaning |
|---|---|
| 920-220REF 3 | 5/9 Secondary reference U.S. Government activity |
| 920-220 | D/9 Drawing number reference only U.S. Government activity |
| 51740B637 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-355-3378 is a Stem,fluid Valve, manufactured by Dover Resources, Inc. Div Norriseal, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-355-3378 has 2 manufacturer part numbers on file: 51740B637 (Dover Resources, Inc. Div Norriseal), 920-220REF 3 (Dover Resources, Inc. Div Norriseal).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-355-6295. Verify interchangeability with system specifications before substitution.
Key specifications for 51740B637: Valve Type for Which Designed: BUTTERFLY; Stem Actuating End Type: THREADED EXTERNALLY; 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.