The Diaphragm, cataloged under National Stock Number 4820-00-421-4437, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 2 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-421-4437 |
| Item Name | Diaphragm |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | MATERIAL WILL BE IN ACCORDANCE WITH NAVICP MECH; ACTIVITY HX QUALITY CONTROL, MANUFACTURING AND TESTING SPECIFICATIONS. |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL F — Mutilate — Cut |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Reference | Meaning |
|---|---|
| 31638PC10 | 5/9 Secondary reference U.S. Government activity |
| C6936D | 3/1 Design control — primary reference U.S. Government activity |
| C6936 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-421-4437 is a Diaphragm, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4820-00-708-0136, 4820-01-556-2926. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-421-4437: Criticality Code Justification: ZZZY; Reference Number Differentiating Characteristics: MATERIAL WILL BE IN ACCORDANCE WITH NAVICP MECH; ACTIVITY HX QUALITY CONTROL, MANUFACTURING AND TESTING SPECIFICATIONS.. 2 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.
NSN 4820-00-421-4437 has DEMIL Code F. Demilitarization may be required before disposal or transfer to non-military entities.
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.