The Valve,safety Relief, cataloged under National Stock Number 4820-00-010-1682, 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 28 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-010-1682 |
| Primary Part Number | A644XB-2-12-2 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Furnished Items and Quantity | 2 FERRULE |
| Connection Style | FLARED (TUBE) ALL ENDS |
| Style Designator | ANGLE |
| Material Document and Classification | FEDSTD66,AISI303/SAE30303 FED STD SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | FEDSTD66,AISI303/SAE30303 FED STD SINGLE MATERIAL RESPONSE SEAT |
| Material Document and Classification | FEDSTD66,AISI416/SAE51416 FED STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Nominal Outside Diameter Tube Accommodated | 0.750 INCHES ALL ENDS IN |
| Operating Pressure | 50.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +10.0 TO 50.0 POUNDS PER SQUARE INCH LBS |
| Features Provided | BONNET PACKING AND PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 1.500 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES ALL ENDS |
| Maximum Operating Temp | 225.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | PASSIVATE LOCATION NOT OTHERWISE SPECIFIED |
| Bonnet Attachment Method | INTEGRAL |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Thread Quantity Per Inch | 12 ALL ENDS |
| Material | STEEL COMP 416 FLOW CONTROL DEVICE |
| Material | STEEL COMP 303 SEAT |
| Material | STEEL COMP 303 BODY |
| Thread Series Designator | UN ALL ENDS |
| Opening Pressure Setting | 35.0 POUNDS PER SQUARE INCH LBS |
| 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 |
|---|---|
| 21C2222-285 | General Electric Company (USA) |
| A644XB-2-12-2 PRIMARY | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division (USA) |
| Reference | Meaning |
|---|---|
| A644X2-12 | 5/9 Secondary reference U.S. Government activity |
| A644XB2-12-2 | 5/9 Secondary reference U.S. Government activity |
| A644X2-2-12 | 5/9 Secondary reference U.S. Government activity |
| 21C2222-285 | 5/9 Secondary reference General Electric Company |
| A644XB2-12 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-010-1682 is a Valve,safety Relief, manufactured by Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-010-1682 has 2 manufacturer part numbers on file: 21C2222-285 (General Electric Company), A644XB-2-12-2 (Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division).
Key specifications for A644XB-2-12-2: Flow Control Device: POPPET; Furnished Items and Quantity: 2 FERRULE; Connection Style: FLARED (TUBE) ALL ENDS; Style Designator: ANGLE. 28 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.