The Valve,vacuum Breaking, cataloged under National Stock Number 4820-01-371-5018, 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 21 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-371-5018 |
| Primary Part Number | 1/2 800MQT |
| Item Name | Valve,vacuum Breaking |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Watts Regulator Company |
| Status | ACTIVE |
| Flow Control Device | DISK, FLAT |
| First End Thread Series Designator | NPT |
| First End Thread Direction | RIGHT-HAND |
| Second End Nominal Thread Size | 0.500 INCHES IN |
| Second End Relationship with First End | NOT IDENTICAL |
| Second End Thread Class | 3A A |
| First End Thread Class | 2B |
| First End Style Designator | PLAIN |
| Second End Thread Series Designator | NPT |
| Second End Nominal Pipe Size Accommodated | 0.500 INCHES IN |
| End Connection Quantity | 2 |
| Second End Thread Direction | RIGHT-HAND |
| Second End Style Designator | PLAIN |
| First End Connection Type | THREADED INTERNAL PIPE |
| Temp Adjustability | NOT ADJUSTABLE |
| First End Nominal Pipe Size Accommodated | 0.500 INCHES IN |
| Material | COPPER ALLOY BODY |
| Material | RUBBER SYNTHETIC FLOW CONTROL DEVICE |
| Material | COPPER ALLOY SEAT |
| Second End Connection Type | THREADED EXTERNAL PIPE |
| First End Nominal Thread Size | 0.500 INCHES 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 |
|---|---|
| 1/2 800MQT PRIMARY | Watts Regulator Company (USA) |
NSN 4820-01-371-5018 is a Valve,vacuum Breaking, manufactured by Watts Regulator Company, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-371-5018 has 1 manufacturer part number on file: 1/2 800MQT (Watts Regulator Company).
Key specifications for 1/2 800MQT: Flow Control Device: DISK, FLAT; First End Thread Series Designator: NPT; First End Thread Direction: RIGHT-HAND; Second End Nominal Thread Size: 0.500 INCHES IN. 21 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.