The Valve,check, cataloged under National Stock Number 4820-01-429-6023, 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 15 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-429-6023 |
| Primary Part Number | 303-HT 1IN |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Core Industries Inc. Dba Mueller Steam Specialty |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN, OPTIONAL END (PIPE) ALL ENDS |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 1.000 INCHES ALL ENDS IN |
| Disk Loading Method | SPRING |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| Material | STEEL UNS J92900 FLOW CONTROL DEVICE |
| Material | STEEL UNS J92900 BODY |
| Material | STEEL COMP 420 STEM |
| Thread Series Designator | NPTF ALL ENDS |
| 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 |
|---|---|
| 303-HT 1IN PRIMARY | Core Industries Inc. Dba Mueller Steam Specialty (USA) |
| 19850B002 IT41 | Engineered Coil Company Dba Engineered Coil Co Div Drs Marlo Coil (USA) |
NSN 4820-01-429-6023 is a Valve,check, manufactured by Core Industries Inc. Dba Mueller Steam Specialty, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-429-6023 has 2 manufacturer part numbers on file: 303-HT 1IN (Core Industries Inc. Dba Mueller Steam Specialty), 19850B002 IT41 (Engineered Coil Company Dba Engineered Coil Co Div Drs Marlo Coil).
Key specifications for 303-HT 1IN: Flow Control Device: DISK; Connection Style: PLAIN, OPTIONAL END (PIPE) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED INTERNAL PIPE ALL ENDS. 15 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.