The Valve,check, cataloged under National Stock Number 4820-01-331-2821, 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 11 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-331-2821 |
| Primary Part Number | 6IN 1601-AC |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Core Industries Inc. Dba Mueller Steam Specialty |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND ALL ENDS |
| Flange Face Design | PLAIN ALL ENDS |
| Mounting Position | HORIZONTAL |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 150.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Nominal Outside Diameter | 6.000 INCHES ALL ENDS IN |
| Material | STEEL BODY |
| Valve Operation Method | AUTOMATIC |
| Nominal Thickness | 1.000 INCHES ALL ENDS IN |
| 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 |
|---|---|
| 6IN 1601-AC PRIMARY | Core Industries Inc. Dba Mueller Steam Specialty (USA) |
| Reference | Meaning |
|---|---|
| 216-32-136 6IN D-04186 | 5/9 Secondary reference Daniel Industries Inc |
| D-04186 1601-AC | 3/9 Design control — primary reference Daniel Industries Inc |
| D-041B6 | D/9 Drawing number reference only Daniel Industries Inc |
NSN 4820-01-331-2821 is a Valve,check, manufactured by Core Industries Inc. Dba Mueller Steam Specialty, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-331-2821 has 1 manufacturer part number on file: 6IN 1601-AC (Core Industries Inc. Dba Mueller Steam Specialty).
Key specifications for 6IN 1601-AC: Flow Control Device: DISK; Flange Shape: ROUND ALL ENDS; Flange Face Design: PLAIN ALL ENDS; Mounting Position: HORIZONTAL. 11 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.