The Valve,check, cataloged under National Stock Number 4820-01-221-7743, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Link-Belt Cranes, L.p., Lllp. Government technical data includes 21 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-221-7743 |
| Primary Part Number | 51J523 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Link-Belt Cranes, L.p., Lllp |
| 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 | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.750 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES ALL ENDS |
| Maximum Operating Temp | 300.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | -40.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | CADMIUM |
| Media for Which Designed | AIR SECOND RESPONSE |
| Media for Which Designed | OIL, HYDRAULIC FIRST RESPONSE |
| Media for Which Designed | WATER, FRESH THIRD RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Thread Quantity Per Inch | 16 ALL ENDS |
| Material | STEEL BODY |
| Thread Series Designator | UNIFIED NATIONAL JOINT (UNJ) 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 |
|---|---|
| 51J523 | Link-Belt Cranes, L.p., Lllp (USA) |
| Reference | Meaning |
|---|---|
| 1308C-1 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-221-7743 is a Valve,check, manufactured by Link-Belt Cranes, L.p., Lllp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-221-7743 has 1 manufacturer part number on file: 51J523 (Link-Belt Cranes, L.p., Lllp).
Key specifications for 51J523: Flow Control Device: POPPET; Connection Style: FLARED (TUBE) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED EXTERNAL TUBE ALL ENDS. 21 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.