The Valve,check, cataloged under National Stock Number 4820-01-425-2135, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Watts Regulator Company. Government technical data includes 19 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-01-425-2135 |
| Primary Part Number | 600-3/4 NPT |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Watts Regulator Company |
| 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 | 125.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Operating Pressure | 400.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.750 INCHES ALL ENDS IN |
| Maximum Operating Temp | -20.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 100.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | WATER-OIL-GAS FIRST RESPONSE |
| Media for Which Designed | STEAM SECOND RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY FLOW CONTROL DEVICE |
| Material | PLASTIC POLYTETRAFLUOROETHYLENE SEAT |
| Thread Series Designator | NPT 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 |
|---|---|
| 600-3/4 NPT PRIMARY | Watts Regulator Company (USA) |
| Reference | Meaning |
|---|---|
| MOD S1-8-C-4 OWS FIG7-1 NO.27 | 5/9 Secondary reference Parmatic Pollution Control Corporation Dba Parmatic Filter |
| PC1215-4 | 5/9 Secondary reference Parmatic Pollution Control Corporation Dba Parmatic Filter |
| MOD S1-8-C-4 OWS TBL7-2 IDX27 | 5/9 Secondary reference Parmatic Pollution Control Corporation Dba Parmatic Filter |
NSN 4820-01-425-2135 is a Valve,check, manufactured by Watts Regulator Company, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-425-2135 has 1 manufacturer part number on file: 600-3/4 NPT (Watts Regulator Company).
Key specifications for 600-3/4 NPT: Flow Control Device: DISK; Connection Style: PLAIN, OPTIONAL END (PIPE) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED INTERNAL PIPE ALL ENDS. 19 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.