The Valve,check, cataloged under National Stock Number 4820-00-006-3987, 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 20 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-00-006-3987 |
| Primary Part Number | 493-12B2-20 |
| 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 |
| Connection Style | GASKET SEAL (BOSS) ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | QQ-B-626,ALLOY 360 FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | MIL-G-1149,TYPE 2 CLASS 3 MIL SPEC SINGLE MATERIAL RESPONSE SEAT |
| Nominal Outside Diameter Tube Accommodated | 0.750 INCHES ALL ENDS IN |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 1.062 INCHES ALL ENDS IN |
| Maximum Operating Temp | 225.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SECOND RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Thread Class | 3B ALL ENDS |
| Thread Quantity Per Inch | 12 ALL ENDS |
| Material | COPPER ALLOY BODY |
| Material | RUBBER SEAT |
| Material | STEEL COMP 304 AND STEEL COMP 303 FLOW CONTROL DEVICE |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) 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 |
|---|---|
| 493-12B2-20 PRIMARY | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division (USA) |
| Reference | Meaning |
|---|---|
| 493-12B2-20 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-006-3987 is a Valve,check, manufactured by Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-006-3987 has 1 manufacturer part number on file: 493-12B2-20 (Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division).
Key specifications for 493-12B2-20: Flow Control Device: POPPET; Connection Style: GASKET SEAL (BOSS) ALL ENDS; Style Designator: STRAIGHT THRU; Material Document and Classification: QQ-B-626,ALLOY 360 FED SPEC SINGLE MATERIAL RESPONSE BODY. 20 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.