The Valve,stop-Check, cataloged under National Stock Number 4820-00-457-0256, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp. Government technical data includes 24 specifications, cited from the U.S. Government catalog. The record lists 4 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-457-0256 |
| Primary Part Number | S6165-20510-001 |
| Item Name | Valve,stop-Check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Style | FLARE (TUBE) SECOND END |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED INTERNAL TUBE SECOND END |
| Style Designator | ANGLE |
| Nominal Outside Diameter Tube Accommodated | 0.250 INCHES SECOND END IN |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Bonnet Type | INSIDE SCREW |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.438 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Mounting Facility | BRACKET(S) |
| Bonnet Attachment Method | THREADED |
| Media for Which Designed | OIL, HYDRAULIC SECOND RESPONSE |
| Media for Which Designed | HYDRAULIC FLUID, PETROLEUM BASE FIRST RESPONSE |
| Thread Class | 2A FIRST END A |
| Thread Class | 2B SECOND END |
| Test Data Document | 81349-MIL-V-5528 SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DATA IN SPECIFICATION FORMAT; EXCLUDES COMMERCIAL CATALOGS, INDUSTRY DIRECTORIES, AND SIMILAR TRADE PUBLICATIONS, REFLECTING GENERAL TYPE DATA ON CERTAIN ENVIRONMENTAL AND PERFORMANCE REQUIREMENTS AND TEST CONDITIONS THAT ARE SHOWN AS "TYPICAL", "AVERAGE", "NOMINAL", ETC.). |
| Material | ALUMINUM ALLOY BODY |
| Material | ALUMINUM ALLOY AND ALUMINUM FLOW CONTROL DEVICE |
| Thread Series Designator | UNF ALL ENDS |
| 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 |
|---|---|
| S6165-20510-1 | Triumph Actuation Systems - Connecticut, Llc (USA) |
| S6165-20510-1 | Rotair Aerospace Corp (USA) |
| S6165-20510-1 | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp (USA) |
| S6165-20510-001 PRIMARY | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp (USA) |
| Reference | Meaning |
|---|---|
| S6165-20510-1 | 5/9 Secondary reference S & L Aerospace Metals Llc |
NSN 4820-00-457-0256 is a Valve,stop-Check, manufactured by Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-457-0256 has 4 manufacturer part numbers on file: S6165-20510-1 (Triumph Actuation Systems - Connecticut, Llc), S6165-20510-1 (Rotair Aerospace Corp), S6165-20510-1 (Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp), S6165-20510-001 (Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp).
Key specifications for S6165-20510-001: Flow Control Device: DISK; Connection Style: FLARED (TUBE) FIRST END; Connection Style: FLARE (TUBE) SECOND END; Mounting Position: HORIZONTAL OR VERTICAL. 24 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.