The Valve,check, cataloged under National Stock Number 4820-01-325-8151, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 24 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 7 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-325-8151 |
| Primary Part Number | 1858654 ITEM 6 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Style | FLARE (TUBE) SECOND END |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED INTERNAL TUBE SECOND END |
| Style Designator | STRAIGHT THRU |
| Nominal Outside Diameter Tube Accommodated | 1.000 INCHES SECOND END IN |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 1.313 INCHES ALL ENDS IN |
| Seat Angle | 45.0 DEGREES FIRST END |
| Maximum Operating Temp | 300.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | 250.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Surface Treatment | CADMIUM |
| Media for Which Designed | AIR FIRST RESPONSE |
| Media for Which Designed | WATER, FRESH SECOND RESPONSE |
| Thread Class | 3A FIRST END A |
| Thread Class | 3B SECOND END |
| Thread Quantity Per Inch | 12 ALL ENDS |
| Material | STEEL BODY |
| Thread Series Designator | UN ALL ENDS |
| Opening Pressure Setting | 5.0 POUNDS PER SQUARE INCH LBS |
| 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 |
|---|---|
| 1858654 ITEM 6 | Northrop Grumman Systems Corporation (USA) |
| 1977621 ITEM 38 | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| 1716C-1-5 | 3/2 Design control — primary reference U.S. Government activity |
| 1858654 | 7/2 Vendor item drawing reference Northrop Grumman Systems Corporation |
| 1858654-6 | C/1 Advisory reference — outside the item-of-supply concept Northrop Grumman Systems Corporation |
| 1977621 | D/9 Drawing number reference only Northrop Grumman Systems Corporation |
NSN 4820-01-325-8151 is a Valve,check, manufactured by Northrop Grumman Systems Corporation, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-325-8151 has 2 manufacturer part numbers on file: 1858654 ITEM 6 (Northrop Grumman Systems Corporation), 1977621 ITEM 38 (Northrop Grumman Systems Corporation).
7 possible matches (shared part number, not a government interchangeability claim): 4820-01-326-0796, 4820-01-326-0840, 4820-01-354-5210. Verify interchangeability with system specifications before substitution.
Key specifications for 1858654 ITEM 6: Flow Control Device: DISK; Connection Style: FLARED (TUBE) FIRST END; Connection Style: FLARE (TUBE) SECOND END; Mounting Position: HORIZONTAL OR VERTICAL. 24 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.