The Valve,check, cataloged under National Stock Number 4820-00-438-0643, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 14 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-438-0643 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Surface Treatment Document and Classification | MIL-A-8625,TYPE 2,CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE |
| Connection Style | GROOVED (TUBE) ALL ENDS |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | UNTHREADED CARTRIDGE ALL ENDS |
| Style Designator | STRAIGHT THRU DROP-IN CARTRIDGE |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Maximum Operating Temp | 275.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | ANODIZE |
| Media for Which Designed | HYDRAULIC FLUID, PHOSPHATE-ESTER BASE SINGLE RESPONSE |
| Material | ALUMINUM ALLOY 2024 BODY |
| Material | STEEL COMP 440C FLOW CONTROL DEVICE |
| Valve Operation Method | AUTOMATIC |
| 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 |
|---|---|
| 2C9490 | 3/2 Design control — primary reference U.S. Government activity |
| 3186842 | 5/9 Secondary reference Allied-Signal Inc Dba Allied-Signal Aerospace Co Electrodynamics Div |
NSN 4820-00-438-0643 is a Valve,check, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 3040-00-589-6484. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-438-0643: Flow Control Device: POPPET; Surface Treatment Document and Classification: MIL-A-8625,TYPE 2,CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE; Connection Style: GROOVED (TUBE) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL. 14 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.