The Valve,check, cataloged under National Stock Number 4820-01-340-5741, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Indal Technologies Inc. Government technical data includes 19 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-340-5741 |
| Primary Part Number | 6534C491-1 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Indal Technologies Inc |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN, OPTIONAL END (PIPE) SECOND END |
| Connection Style | PLAIN (PIPE) FIRST END |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Criticality Code Justification | FEAT |
| Connection Type | THREADED INTERNAL TUBE SECOND END |
| Connection Type | THREADED EXTERNAL PIPE FIRST END |
| Style Designator | STRAIGHT THRU |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES SECOND END IN |
| Operating Pressure | 5500.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Nominal Thread Size | 0.750 INCHES SECOND END IN |
| Nominal Thread Size | 0.500 INCHES FIRST END IN |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SINGLE RESPONSE |
| Thread Class | 2B SECOND END |
| Material | STEEL BODY |
| Thread Series Designator | UNF SECOND END |
| Opening Pressure Setting | 15.0 POUNDS PER SQUARE INCH LBS |
| 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 | Y |
| Part Number | Manufacturer |
|---|---|
| 6534C491-1 PRIMARY | Indal Technologies Inc (CAN) |
| Reference | Meaning |
|---|---|
| 6534C491 | 1/2 Source control — Government-approved source U.S. Government activity |
| 6534C491-1 | 5/2 Secondary reference U.S. Government activity |
| 741-115 | 5/9 Secondary reference Safran Landing Systems Canada Inc. |
| 6534C91-1 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-340-5741 is a Valve,check, manufactured by Indal Technologies Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-340-5741 has 1 manufacturer part number on file: 6534C491-1 (Indal Technologies Inc).
Key specifications for 6534C491-1: Flow Control Device: DISK; Connection Style: PLAIN, OPTIONAL END (PIPE) SECOND END; Connection Style: PLAIN (PIPE) FIRST END; Mounting Position: HORIZONTAL OR VERTICAL. 19 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.