The Valve,restrictor Check, cataloged under National Stock Number 4820-00-284-1027, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 19 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-284-1027 |
| Item Name | Valve,restrictor Check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | FLARELESS ALL ENDS |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.438 INCHES SECOND END IN |
| Nominal Thread Size | 0.562 INCHES FIRST END IN |
| Seat Angle | 12.0 DEGREES ALL ENDS |
| Maximum Operating Temp | 275.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | -65.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | PASSIVATE |
| Media for Which Designed | HYDRAULIC FLUID, PHOSPHATE-ESTER BASE SINGLE RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Material | STEEL COMP 630 OVERALL |
| 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 |
| Reference | Meaning |
|---|---|
| 6F2966-129 | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
| 4R122-129 | 3/2 Design control — primary reference U.S. Government activity |
| 4R122 | D/9 Drawing number reference only U.S. Government activity |
| 749959-129 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-00-284-1027 is a Valve,restrictor Check, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-284-1027: Flow Control Device: POPPET; Connection Style: FLARELESS ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED EXTERNAL TUBE ALL ENDS. 19 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.