The Valve,safety Relief, cataloged under National Stock Number 4820-01-117-1577, 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 24 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-117-1577 |
| Primary Part Number | 626B-6-1/4-2 |
| 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 |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | ANGLE |
| Material Document and Classification | AISI 416 ASSN STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Material Document and Classification | QQ-A-225/4,ALLOY 2014,T4 FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Operating Pressure | 650.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +430.0 TO 650.0 POUNDS PER SQUARE INCH 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 | 225.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | OIL, HYDRAULIC SECOND RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Material | STEEL COMP 416 FLOW CONTROL DEVICE |
| Material | RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR SEAT |
| Material | ALUMINUM ALLOY 2014 BODY |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 550.0 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 |
|---|---|
| 626B-6-1/4-2 | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division (USA) |
| Reference | Meaning |
|---|---|
| 5165982 | 7/2 Vendor item drawing reference Naval Sea Systems Command |
| 621B-6-1/4-2 | 5/9 Secondary reference U.S. Government activity |
| 621B-6-1/4-2 | 3/9 Design control — primary reference Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division |
NSN 4820-01-117-1577 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 4820-01-117-1577 has 1 manufacturer part number on file: 626B-6-1/4-2 (Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division).
1 possible match (shared part number, not a government interchangeability claim): 4720-01-676-8110. Verify interchangeability with system specifications before substitution.
Key specifications for 626B-6-1/4-2: Flow Control Device: POPPET; Connection Style: PLAIN,OPTIONAL END(PIPE) FIRST END; Connection Style: PLAIN (PIPE) SECOND END; Connection Type: THREADED INTERNAL PIPE FIRST END. 24 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.