The Valve,check, cataloged under National Stock Number 4820-00-618-8458, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division. Government technical data includes 22 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-618-8458 |
| Primary Part Number | 481-1/4D1-2 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Surface Treatment Document and Classification | MIL-A-8625,TY 2 MIL SPEC SINGLE TREATMENT RESPONSE |
| Connection Style | PLAIN, OPTIONAL END (PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Mounting Position | HORIZONTAL |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.250 INCHES FIRST END IN |
| Nominal Thread Size | 0.250 INCHES SECOND END IN |
| Maximum Operating Temp | 200.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | ANODIZE |
| Material | STEEL COMP 304 FLOW CONTROL DEVICE |
| Material | RUBBER SEAT |
| Material | ALUMINUM BODY |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT 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 |
|---|---|
| 481-1/4D1-2 PRIMARY | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division (USA) |
| 321881P3 | Meggitt (north Hollywood), Inc. Dba Meggitt Control Systems Div Meggitt Defense Systems, Inc. (USA) |
| Reference | Meaning |
|---|---|
| 321881P3 | 5/9 Secondary reference Howden Fluid Systems |
| 10667857 | 7/2 Vendor item drawing reference Us Army Aviation and Missile Command |
| 481 1-4D2 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-618-8458 is a Valve,check, manufactured by Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-618-8458 has 2 manufacturer part numbers on file: 481-1/4D1-2 (Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division), 321881P3 (Meggitt (north Hollywood), Inc. Dba Meggitt Control Systems Div Meggitt Defense Systems, Inc.).
1 possible match (shared part number, not a government interchangeability claim): 4820-00-891-4178. Verify interchangeability with system specifications before substitution.
Key specifications for 481-1/4D1-2: Flow Control Device: POPPET; Surface Treatment Document and Classification: MIL-A-8625,TY 2 MIL SPEC SINGLE TREATMENT RESPONSE; Connection Style: PLAIN, OPTIONAL END (PIPE) FIRST END; Connection Style: PLAIN (PIPE) SECOND END. 22 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.