The Valve,bleeder,hydraulic System, cataloged under National Stock Number 4820-01-281-4378, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Swagelok Co. Government technical data includes 14 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-281-4378 |
| Primary Part Number | SS-4P-4ST |
| Item Name | Valve,bleeder,hydraulic System |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Swagelok Co |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN (TUBE) ALL ENDS |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Operating Pressure | 4000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Maximum Operating Temp | 600.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | GAS, NATURAL SECOND RESPONSE |
| Media for Which Designed | STEAM THIRD RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Thread Class | 2A ALL ENDS A |
| Material | STEEL COMP 316 BODY |
| Material | STEEL COMP 316 FLOW CONTROL DEVICE |
| Thread Series Designator | UNF ALL ENDS |
| 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 |
|---|---|
| SS-4P-4ST PRIMARY | Swagelok Co (USA) |
| Reference | Meaning |
|---|---|
| SS-4P-4ST | 5/9 Secondary reference Nupro Co |
NSN 4820-01-281-4378 is a Valve,bleeder,hydraulic System, manufactured by Swagelok Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-281-4378 has 1 manufacturer part number on file: SS-4P-4ST (Swagelok Co).
Key specifications for SS-4P-4ST: Flow Control Device: POPPET; Connection Style: PLAIN (TUBE) ALL ENDS; Connection Type: THREADED EXTERNAL TUBE ALL ENDS; Operating Pressure: 4000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS. 14 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.