The Valve,check, cataloged under National Stock Number 4820-00-203-3669, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 20 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-00-203-3669 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN, OPTIONAL END (PIPE) FIRST END |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | QQ-C-390,ALLOY D4 FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | ASTM B-16 ASSN STD SINGLE MATERIAL RESPONSE STEM |
| Operating Pressure | 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Operating Pressure | 125.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Maximum Operating Temp | 125.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 125.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Nondefinitive Spec/std Data | 3 TYPE AND A CLASS |
| Media for Which Designed | WATER-OIL-GAS SECOND RESPONSE |
| Media for Which Designed | STEAM FIRST RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY STEM |
| Thread Series Designator | NPT FIRST END |
| 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 |
|---|---|
| WW-V-51 | 4/1 Identification reference U.S. Government activity |
NSN 4820-00-203-3669 is a Valve,check, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-203-3669: Flow Control Device: DISK; Connection Style: PLAIN, OPTIONAL END (PIPE) FIRST END; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED INTERNAL PIPE FIRST END. 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.