The Valve,check, cataloged under National Stock Number 4820-00-494-1332, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Ausco Inc. Government technical data includes 29 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-494-1332 |
| Primary Part Number | H539 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Ausco Inc |
| Status | ACTIVE |
| Flow Control Device | POPPETPOPPET |
| Connection Style | EXTERNAL SEAT FOR GASKET SEAL (BOSS) SECOND ENDEXTERNAL SEAT FOR GASKET SEAL (BOSS) SECOND END |
| Connection Style | FLARED (TUBE) FIRST ENDFLARED (TUBE) FIRST END |
| Mounting Position | HORIZONTALHORIZONTAL |
| Connection Type | THREADED EXTERNAL TUBE FIRST ENDTHREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED EXTERNAL BOSS SECOND ENDTHREADED EXTERNAL BOSS SECOND END |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | AMS 5643 ASSN STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Material Document and Classification | AMS 5643 ASSN STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICEQQ-A-225/6,ALLOY 2024 FED SPEC SINGLE MATERIAL RESPONSE SEAT |
| Material Document and Classification | QQ-A-225/6,ALLOY 2024 FED SPEC SINGLE MATERIAL RESPONSE SEATQQ-A-225/6,ALLOY 2024 FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Nominal Outside Diameter Tube Accommodated | 0.375 INCHES SECOND END IN |
| Nominal Outside Diameter Tube Accommodated | 0.375 INCHES SECOND END0.250 INCHES FIRST END IN |
| Operating Pressure | 4000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND SECOND ENDRIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST ENDRIGHT-HAND FIRST END |
| Nominal Thread Size | 0.562 INCHES SECOND END0.562 INCHES SECOND END IN |
| Nominal Thread Size | 0.437 INCHES FIRST END0.437 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Maximum Operating Temp | 300.0 FAHRENHEIT SINGLE RESPONSE300.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRINGSPRING |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| Thread Class | 3A SECOND END3A SECOND END A |
| Thread Class | 3A FIRST END3A FIRST END A |
| Material | STEEL COMP 630 FLOW CONTROL DEVICE |
| Material | ALUMINUM ALLOY 2024 SEATALUMINUM ALLOY 2024 BODY |
| Material | STEEL COMP 630 FLOW CONTROL DEVICEALUMINUM ALLOY 2024 SEAT |
| Thread Series Designator | UNF SECOND END |
| Thread Series Designator | UNF SECOND ENDUNF FIRST END |
| Valve Operation Method | AUTOMATICAUTOMATIC |
| 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 |
|---|---|
| H539 PRIMARY | Ausco Inc (USA) |
| Reference | Meaning |
|---|---|
| 991722-1 | 7/2 Vendor item drawing reference U.S. Government activity |
NSN 4820-00-494-1332 is a Valve,check, manufactured by Ausco Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-494-1332 has 1 manufacturer part number on file: H539 (Ausco Inc).
Key specifications for H539: Flow Control Device: POPPETPOPPET; Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) SECOND ENDEXTERNAL SEAT FOR GASKET SEAL (BOSS) SECOND END; Connection Style: FLARED (TUBE) FIRST ENDFLARED (TUBE) FIRST END; Mounting Position: HORIZONTALHORIZONTAL. 29 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.