The Valve,bleeder,hydraulic System, cataloged under National Stock Number 4820-00-172-8792, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Swagelok Co. Government technical data includes 13 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-172-8792 |
| Primary Part Number | B4P-4M |
| Item Name | Valve,bleeder,hydraulic System |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Swagelok Co |
| Status | ACTIVE |
| Flow Control Device | BALL |
| Connection Style | PLAIN (PIPE) ALL ENDS |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Operating Pressure | 3000.0 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 | 400.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | AIR FIRST RESPONSE |
| Media for Which Designed | WATER, FRESH SECOND RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | STEEL COMP 316 FLOW CONTROL DEVICE |
| 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 |
|---|---|
| 5409159 | Naval Sea Systems Command (USA) |
| B4P-4M PRIMARY | Swagelok Co (USA) |
| Reference | Meaning |
|---|---|
| 1551AS397-1 | C/1 Advisory reference — outside the item-of-supply concept Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
| 306E | 5/9 Secondary reference Imperial |
| 17-010-002 | 5/9 Secondary reference Norgren C a Co |
| B4P-4M | 5/9 Secondary reference Nupro Co |
NSN 4820-00-172-8792 is a Valve,bleeder,hydraulic System, manufactured by Swagelok Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-172-8792 has 2 manufacturer part numbers on file: 5409159 (Naval Sea Systems Command), B4P-4M (Swagelok Co).
1 possible match (shared part number, not a government interchangeability claim): 4510-01-417-1456. Verify interchangeability with system specifications before substitution.
Key specifications for B4P-4M: Flow Control Device: BALL; Connection Style: PLAIN (PIPE) ALL ENDS; Connection Type: THREADED EXTERNAL PIPE ALL ENDS; Operating Pressure: 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS. 13 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.