The Valve,check, cataloged under National Stock Number 4820-01-059-1172, 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-059-1172 |
| Primary Part Number | L81400-20MMK |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Lourdes Industries, Inc. |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN (TUBE) ALL ENDS |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | UNTHREADED INTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | QQ-A-200/3, ALLOY 2024, T4 FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Material Document and Classification | QQ-A-225/8, ALLOY 6061, T651 FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | QQ-A-225/8, ALLOY 6061, T651 FED SPEC SINGLE MATERIAL RESPONSE SEAT |
| Nominal Outside Diameter Tube Accommodated | 1.250 INCHES ALL ENDS IN |
| Operating Pressure | 400.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Maximum Operating Temp | 400.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SECOND RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Material | ALUMINUM ALLOY 2024 FLOW CONTROL DEVICE |
| Material | ALUMINUM ALLOY 6061 BODY |
| Material | ALUMINUM ALLOY 6061 SEAT |
| 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 |
|---|---|
| L81400-20MMK PRIMARY | Lourdes Industries, Inc. (USA) |
| GV500TC20MMK | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| GV500TC | D/9 Drawing number reference only Northrop Grumman Systems Corporation |
NSN 4820-01-059-1172 is a Valve,check, manufactured by Lourdes Industries, Inc., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-059-1172 has 2 manufacturer part numbers on file: L81400-20MMK (Lourdes Industries, Inc.), GV500TC20MMK (Northrop Grumman Systems Corporation).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-059-1173, 4820-01-259-0347, 4820-01-259-2204. Verify interchangeability with system specifications before substitution.
Key specifications for L81400-20MMK: Flow Control Device: POPPET; Connection Style: PLAIN (TUBE) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: UNTHREADED INTERNAL TUBE ALL ENDS. 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.