The Valve,check, cataloged under National Stock Number 4820-01-420-9955, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Parker Hannifin Corp Aerospace Group Aerospace Hydraulics Div. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-420-9955 |
| Primary Part Number | 65920-1 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Parker Hannifin Corp Aerospace Group Aerospace Hydraulics Div |
| Status | ACTIVE |
| 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 |
|---|---|
| 65920-1 PRIMARY | Parker Hannifin Corp Aerospace Group Aerospace Hydraulics Div (USA) |
| 65920-1 PRIMARY | Parker-Hannifin Corporation Dba Service and Support Operation Div Services and Support Operations (USA) |
| Reference | Meaning |
|---|---|
| 65920-1 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-420-9955 is a Valve,check, manufactured by Parker Hannifin Corp Aerospace Group Aerospace Hydraulics Div, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-420-9955 has 2 manufacturer part numbers on file: 65920-1 (Parker Hannifin Corp Aerospace Group Aerospace Hydraulics Div), 65920-1 (Parker-Hannifin Corporation Dba Service and Support Operation Div Services and Support Operations).
2 possible matches (shared part number, not a government interchangeability claim): 4510-01-426-4187, 6110-01-438-1140. Verify interchangeability with system specifications before substitution.
Key specifications for 65920-1: End Item Identification: AIRCRAFT,AIRLIFTER C-17A A. 0 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.