The Valve,check, cataloged under National Stock Number 4820-00-835-4847, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Marmon-Herrington Company. Government technical data includes 23 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-00-835-4847 |
| Primary Part Number | R2A7558 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Marmon-Herrington Company |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Nominal Pipe Size Accommodated | 1.500 INCHES SECOND END IN |
| Nominal Pipe Size Accommodated | 0.750 INCHES FIRST END IN |
| Connection Style | PLAIN, OPTIONAL END (PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 1.500 INCHES SECOND END IN |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Maximum Operating Temp | 500.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | PASSIVATE |
| Media for Which Designed | STEAM SINGLE RESPONSE |
| Thread Quantity Per Inch | 11-1/2 SECOND END |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | NPT SECOND END |
| 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 |
| Part Number | Manufacturer |
|---|---|
| R2A7558 PRIMARY | Marmon-Herrington Company (USA) |
| Reference | Meaning |
|---|---|
| R2A7558 | 5/9 Secondary reference Long-Airdox Co |
NSN 4820-00-835-4847 is a Valve,check, manufactured by Marmon-Herrington Company, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-835-4847 has 1 manufacturer part number on file: R2A7558 (Marmon-Herrington Company).
Key specifications for R2A7558: Flow Control Device: DISK; Nominal Pipe Size Accommodated: 1.500 INCHES SECOND END IN; Nominal Pipe Size Accommodated: 0.750 INCHES FIRST END IN; Connection Style: PLAIN, OPTIONAL END (PIPE) FIRST END. 23 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.