The Valve,check, cataloged under National Stock Number 4820-01-087-3256, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 24 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-087-3256 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | FLARED (TUBE) ALL ENDS |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Criticality Code Justification | FEAT |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | QQ-A-225/6,T4 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Operating Pressure | 600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Operating Pressure | 600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Operating Pressure | 600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM THIRD RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.562 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES ALL ENDS |
| Maximum Operating Temp | 500.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | 500.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 500.0 FAHRENHEIT THIRD RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | OXYGEN, GASEOUS THIRD RESPONSE |
| Media for Which Designed | NITROGEN, GASEOUS SECOND RESPONSE |
| Media for Which Designed | CARBON DIOXIDE FIRST RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Material | ALUMINUM ALLOY 2024 OVERALL |
| Thread Series Designator | UNF 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 | Y |
| Reference | Meaning |
|---|---|
| 824A12TT | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-087-3256 is a Valve,check, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-087-3256: Flow Control Device: POPPET; Connection Style: FLARED (TUBE) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Criticality Code Justification: FEAT. 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.