The Diaphragm,valve,flat, cataloged under National Stock Number 4820-01-123-4135, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Bellofram Corporation. Government technical data includes 4 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-123-4135 |
| Primary Part Number | 4-87-75-BBJ-1 |
| Item Name | Diaphragm,valve,flat |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Bellofram Corporation |
| Status | ACTIVE |
| Outside Diameter | 1.375 INCHES NOMINAL IN |
| Material Document and Classification | DUPONT 50294, SYNTHETIC RUBBER W/NITRIL ELASTOMER MFR REF SINGLE MATERIAL RESPONSE |
| Center Hole Diameter | 0.188 INCHES NOMINAL IN |
| Material | RUBBER SYNTHETIC |
| 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 |
|---|---|
| 4-87-75-BBJ-1 PRIMARY | Bellofram Corporation (USA) |
| Reference | Meaning |
|---|---|
| 98785 FIND 12 | 5/9 Secondary reference U.S. Government activity |
| 98785 PART 80342 | 5/9 Secondary reference U.S. Government activity |
| 80342 | 5/9 Secondary reference U.S. Government activity |
| 98785 | D/9 Drawing number reference only U.S. Government activity |
| 80342K | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-123-4135 is a Diaphragm,valve,flat, manufactured by Bellofram Corporation, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-123-4135 has 1 manufacturer part number on file: 4-87-75-BBJ-1 (Bellofram Corporation).
2 possible matches (shared part number, not a government interchangeability claim): 4820-01-536-6523, 6220-01-624-1499. Verify interchangeability with system specifications before substitution.
Key specifications for 4-87-75-BBJ-1: Outside Diameter: 1.375 INCHES NOMINAL IN; Material Document and Classification: DUPONT 50294, SYNTHETIC RUBBER W/NITRIL ELASTOMER MFR REF SINGLE MATERIAL RESPONSE; Center Hole Diameter: 0.188 INCHES NOMINAL IN; Material: RUBBER SYNTHETIC. 4 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.