The Diaphragm,valve,flat, cataloged under National Stock Number 4820-01-050-4634, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Metrex Valve Corp. Dba Metrex Valve Corp. Government technical data includes 8 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-050-4634 |
| Primary Part Number | 31M 38 |
| Item Name | Diaphragm,valve,flat |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Metrex Valve Corp. Dba Metrex Valve Corp |
| Status | ACTIVE |
| Outside Diameter | 15.125 INCHES NOMINAL IN |
| Style Designator | FLAT |
| Material Thickness | 0.132 INCHES NOMINAL IN |
| Bolt Hole Quantity | 30 |
| Bolt Circle Diameter | 13.625 INCHES NOMINAL IN |
| Center Hole Diameter | 0.750 INCHES NOMINAL IN |
| Material | RUBBER |
| Hole Diameter | 0.515 INCHES NOMINAL IN |
| 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 |
|---|---|
| 31M 38 PRIMARY | Metrex Valve Corp. Dba Metrex Valve Corp (USA) |
| Reference | Meaning |
|---|---|
| YM-3145PIECE46 | 5/9 Secondary reference Metrex Valve Corp. Dba Metrex Valve Corp |
| YM-3145 | D/9 Drawing number reference only Metrex Valve Corp. Dba Metrex Valve Corp |
NSN 4820-01-050-4634 is a Diaphragm,valve,flat, manufactured by Metrex Valve Corp. Dba Metrex Valve Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-050-4634 has 1 manufacturer part number on file: 31M 38 (Metrex Valve Corp. Dba Metrex Valve Corp).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-490-0984. Verify interchangeability with system specifications before substitution.
Key specifications for 31M 38: Outside Diameter: 15.125 INCHES NOMINAL IN; Style Designator: FLAT; Material Thickness: 0.132 INCHES NOMINAL IN; Bolt Hole Quantity: 30. 8 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.