The Valve,check, cataloged under National Stock Number 4820-01-259-0347, 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 20 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-259-0347 |
| Primary Part Number | L81400-6SSK |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Lourdes Industries, Inc. |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | FLARED (TUBE) ALL ENDS |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 400.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.563 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES ALL ENDS |
| Maximum Operating Temp | 400.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | -65.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SECOND RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | ALUMINUM ALLOY 6061 BODY |
| Material | RUBBER FLUOROCARBON CLASS FPM SEAT |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS |
| 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 |
|---|---|
| GV500TC6SSK | Northrop Grumman Systems Corporation (USA) |
| L81400-6SSK PRIMARY | Lourdes Industries, Inc. (USA) |
| Reference | Meaning |
|---|---|
| GV500TC | D/9 Drawing number reference only Northrop Grumman Systems Corporation |
NSN 4820-01-259-0347 is a Valve,check, manufactured by Lourdes Industries, Inc., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-259-0347 has 2 manufacturer part numbers on file: GV500TC6SSK (Northrop Grumman Systems Corporation), L81400-6SSK (Lourdes Industries, Inc.).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-259-2204. Verify interchangeability with system specifications before substitution.
Key specifications for L81400-6SSK: Flow Control Device: POPPET; Connection Style: FLARED (TUBE) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED EXTERNAL TUBE ALL ENDS. 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.