The Valve,regulating,fluid Pressure, cataloged under National Stock Number 4820-00-991-0858, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 20 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-00-991-0858 |
| Primary Part Number | MDE321409-5 |
| Item Name | Valve,regulating,fluid Pressure |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Flow Control Device | DIAPHRAGM |
| First End Thread Direction | RIGHT-HAND |
| Second End Relationship with First End | IDENTICAL |
| Remote Actuation Method | DIAPHRAGM |
| Body Style | TEE |
| Regulation Type | AUTOMATIC SINGLE STAGE |
| First End Seat Angle in Deg | 12.5 |
| First End Thread Class | 3B |
| Third End Relationship with Preceding Ends | IDENTICAL WITH FIRST END |
| First End Style Designator | FLARE |
| Temp Rating | -40.0 FAHRENHEIT MINIMUM AND 250.0 FAHRENHEIT MAXIMUM DEGF |
| End Connection Quantity | 3 |
| Valve Loading Method | SPRING |
| First End Connection Type | THREADED INTERNAL TUBE |
| First End Outside Diameter Tube Accommodated | 0.312 INCHES NOMINAL IN |
| Material | STEEL CORROSION RESISTING BODY |
| Maximum Inlet Pressure Rating | ERR-060 |
| Furnished Items | PANEL MOUNTING BRACKET |
| Thread Size and Series/type Designator | 1/2-18 UNS FIRST END |
| Filter | NOT INCLUDED |
| 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 |
|---|---|
| MDE321409-5 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| 63SU | 5/1 Secondary reference Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives |
NSN 4820-00-991-0858 is a Valve,regulating,fluid Pressure, manufactured by The Boeing Company Div Defense, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-991-0858 has 1 manufacturer part number on file: MDE321409-5 (The Boeing Company Div Defense).
Key specifications for MDE321409-5: Flow Control Device: DIAPHRAGM; First End Thread Direction: RIGHT-HAND; Second End Relationship with First End: IDENTICAL; Remote Actuation Method: DIAPHRAGM. 20 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.