The Valve,check, cataloged under National Stock Number 4820-01-581-6645, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Core Industries Inc. Dba Mueller Steam Specialty. Government technical data includes 12 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-581-6645 |
| Primary Part Number | 1601-C-4.0IN |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Core Industries Inc. Dba Mueller Steam Specialty |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 185.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Operating Pressure | 275.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Maximum Operating Temp | 450.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 100.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Mounting Facility | WAFER |
| Media for Which Designed | AIR SINGLE RESPONSE |
| Material | STEEL CORROSION RESISTING BODY |
| 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 |
| Part Number | Manufacturer |
|---|---|
| 1601-C-4.0IN PRIMARY | Core Industries Inc. Dba Mueller Steam Specialty (USA) |
| Reference | Meaning |
|---|---|
| CHX-4.0-1-216-33-091 150LB RF | 5/1 Secondary reference Core Industries Inc. Dba Mueller Steam Specialty |
NSN 4820-01-581-6645 is a Valve,check, manufactured by Core Industries Inc. Dba Mueller Steam Specialty, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-581-6645 has 1 manufacturer part number on file: 1601-C-4.0IN (Core Industries Inc. Dba Mueller Steam Specialty).
Key specifications for 1601-C-4.0IN: Flow Control Device: DISK; Mounting Position: HORIZONTAL OR VERTICAL; Style Designator: STRAIGHT THRU; Operating Pressure: 185.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS. 12 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.