The Valve,check, cataloged under National Stock Number 4820-01-124-3688, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 20 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-124-3688 |
| Primary Part Number | 74B580185-103 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Style | GROOVED (TUBE) SECOND END |
| Mounting Position | HORIZONTAL |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | UNTHREADED EXTERNAL TUBE SECOND END |
| Style Designator | STRAIGHT THRU |
| Nominal Outside Diameter Tube Accommodated | 1.250 INCHES SECOND END IN |
| Operating Pressure | 110.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 1.625 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Maximum Operating Temp | 400.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SECOND RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Thread Class | 3A FIRST END A |
| Thread Quantity Per Inch | 12 FIRST END |
| Material | ALUMINUM ALLOY OVERALL |
| Thread Series Designator | UN FIRST END |
| Valve Operation Method | AUTOMATIC |
| 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 |
|---|---|
| 74B580185-103 | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| P112-533 | D/9 Drawing number reference only U.S. Government activity |
| P112-533-20 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-124-3688 is a Valve,check, manufactured by The Boeing Company Div Defense, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-124-3688 has 1 manufacturer part number on file: 74B580185-103 (The Boeing Company Div Defense).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-125-5504. Verify interchangeability with system specifications before substitution.
Key specifications for 74B580185-103: Flow Control Device: DISK; Connection Style: FLARED (TUBE) FIRST END; Connection Style: GROOVED (TUBE) SECOND END; Mounting Position: HORIZONTAL. 20 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.