The Valve,check, cataloged under National Stock Number 4820-00-409-1734, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Lourdes Industries, Inc.. Government technical data includes 17 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-409-1734 |
| Primary Part Number | L56800-1 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Lourdes Industries, Inc. |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | FLARED (TUBE) FIRST END |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Style Designator | STRAIGHT THRU |
| Nominal Outside Diameter Tube Accommodated | 1.000 INCHES FIRST END IN |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 1.312 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Maximum Operating Temp | 200.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | ACETYLENE SINGLE 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 |
|---|---|
| A51E9070-1 | Northrop Grumman Systems Corporation (USA) |
| L56800-1 PRIMARY | Lourdes Industries, Inc. (USA) |
| Reference | Meaning |
|---|---|
| A51E9070-1 | 5/9 Secondary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp Div Northrop Grumman Aeronautics Systems |
| A51E9070 | D/9 Drawing number reference only Northrop Grumman Systems Corporation |
NSN 4820-00-409-1734 is a Valve,check, manufactured by Lourdes Industries, Inc., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-409-1734 has 2 manufacturer part numbers on file: A51E9070-1 (Northrop Grumman Systems Corporation), L56800-1 (Lourdes Industries, Inc.).
Key specifications for L56800-1: Flow Control Device: POPPET; Connection Style: FLARED (TUBE) FIRST END; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED EXTERNAL TUBE FIRST END. 17 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.