The Valve,check, cataloged under National Stock Number 4820-01-648-3841, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is The Entwistle Company Llc. Government technical data includes 12 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-648-3841 |
| Primary Part Number | 0418C17-0338-01 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | The Entwistle Company Llc |
| Status | ACTIVE |
| Connection Style | PLAIN, OPTIONAL END (PIPE) ALL ENDS |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 400.00 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.25 INCHES ALL ENDS IN |
| Maximum Operating Temp | 210.00 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Material | COPPER ALLOY BODY |
| Material | RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR SEAT |
| Thread Series Designator | NPT 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 |
|---|---|
| 0418C17-0338-01 PRIMARY | The Entwistle Company Llc (USA) |
| Reference | Meaning |
|---|---|
| BC-2 | 5/9 Secondary reference Thg Corporation Dba Sorensen Systems |
NSN 4820-01-648-3841 is a Valve,check, manufactured by The Entwistle Company Llc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-648-3841 has 1 manufacturer part number on file: 0418C17-0338-01 (The Entwistle Company Llc).
Key specifications for 0418C17-0338-01: Connection Style: PLAIN, OPTIONAL END (PIPE) ALL ENDS; Connection Type: THREADED INTERNAL PIPE ALL ENDS; Style Designator: STRAIGHT THRU; Operating Pressure: 400.00 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS. 12 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.