The Valve,check, cataloged under National Stock Number 4820-01-313-4127, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Swagelok Co. Government technical data includes 17 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-313-4127 |
| Primary Part Number | B-8C4-C1-1/3 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Swagelok Co |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN, OPTIONAL END (PIPE) ALL ENDS |
| Mounting Position | HORIZONTAL |
| Connection Type | THREADED INTERNAL PIPE 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 | 0.500 INCHES ALL ENDS IN |
| Maximum Operating Temp | 300.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | LIQUID SECOND RESPONSE |
| Media for Which Designed | GAS, NATURAL FIRST RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY FLOW CONTROL DEVICE |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 0.3 POUNDS PER SQUARE INCH LBS |
| 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 |
|---|---|
| B-8C4-C1-1/3 PRIMARY | Swagelok Co (USA) |
| Reference | Meaning |
|---|---|
| B-8C4-C1-1/3 | 5/9 Secondary reference Nupro Co |
| B-8C4-1/3 | 5/9 Secondary reference Nupro Co |
NSN 4820-01-313-4127 is a Valve,check, manufactured by Swagelok Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-313-4127 has 1 manufacturer part number on file: B-8C4-C1-1/3 (Swagelok Co).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-720-7852. Verify interchangeability with system specifications before substitution.
Key specifications for B-8C4-C1-1/3: Flow Control Device: POPPET; Connection Style: PLAIN, OPTIONAL END (PIPE) ALL ENDS; Mounting Position: HORIZONTAL; Connection Type: THREADED INTERNAL PIPE ALL ENDS. 17 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.