The Orifice Block and Disk Assembly, cataloged under National Stock Number 4820-01-129-5637, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 1 specification, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-129-5637 |
| Item Name | Orifice Block and Disk Assembly |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| General Characteristics Item Description | CONSISTS OF DISK COMPRESSOR 1;ORIFICE BLOCK 1;SOCKET HEAD SHOULDER SCREW 3;DISK AS REQUIRED |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| V3C10158-621 | 3/2 Design control — primary reference U.S. Government activity |
| V3E10012 ITEM 1 | 5/2 Secondary reference U.S. Government activity |
| V3E10012 | D/9 Drawing number reference only U.S. Government activity |
NSN 4820-01-129-5637 is a Orifice Block and Disk Assembly, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-01-131-4917. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-129-5637: General Characteristics Item Description: CONSISTS OF DISK COMPRESSOR 1;ORIFICE BLOCK 1;SOCKET HEAD SHOULDER SCREW 3;DISK AS REQUIRED. 1 specification is 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.