The Valve,safety Relief, cataloged under National Stock Number 4820-00-045-3544, 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 16 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-045-3544 |
| Primary Part Number | 634XB-10-8-2 |
| 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 | CONE |
| Connection Style | FLARED (TUBE) ALL ENDS |
| Style Designator | ANGLE |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES ALL ENDS IN |
| Adjustable Pressure Range | +1400.0 TO 2100.0 POUNDS PER SQUARE INCH LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.750 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES ALL ENDS |
| Disk Loading Method | SPRING |
| Thread Class | 3A ALL ENDS A |
| Thread Quantity Per Inch | 16 ALL ENDS |
| Material | COPPER ALLOY OVERALL |
| Thread Series Designator | UNF ALL ENDS |
| Opening Pressure Setting | 1750.0 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 |
|---|---|
| 634XB-10-8-2 PRIMARY | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division (USA) |
| Reference | Meaning |
|---|---|
| L6751 | 5/9 Secondary reference Pettibone Llc |
| 2-464-1 | 5/9 Secondary reference U.S. Government activity |
| 634XB10-8-2 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-045-3544 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 4820-00-045-3544 has 1 manufacturer part number on file: 634XB-10-8-2 (Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-225-6857, 6110-01-313-7045, 5310-01-590-3342. Verify interchangeability with system specifications before substitution.
Key specifications for 634XB-10-8-2: Flow Control Device: CONE; Connection Style: FLARED (TUBE) ALL ENDS; Style Designator: ANGLE; Nominal Outside Diameter Tube Accommodated: 0.500 INCHES ALL ENDS IN. 16 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.