The Valve,vacuum Breaking, cataloged under National Stock Number 4820-01-520-4790, 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 12 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 | 4820-01-520-4790 |
| Primary Part Number | 800M4-QT .750 IN |
| Item Name | Valve,vacuum Breaking |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Watts Regulator Company |
| Status | ACTIVE |
| Flow Control Device | DISK, FLAT |
| Temp Rating | 140.0 FAHRENHEIT DEGF |
| Temp Rating | 33.0 FAHRENHEIT DEGF |
| Second End Relationship with First End | IDENTICAL |
| Body Style | ANGLE GIVE "ADQM" AND "ADQN" ONLY IF FLANGED ONE OR TWO ENDS |
| Third End Relationship with Preceding Ends | IDENTICAL WITH FIRST END |
| First End Style Designator | PLAIN |
| Material Document and Classification | ASTM B61 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| End Connection Quantity | 2 |
| First End Connection Type | THREADED EXTERNAL PIPE |
| Temp Adjustability | NOT ADJUSTABLE |
| Material | COPPER ALLOY 922 BODY |
| 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 |
|---|---|
| 800M4-QT .750 IN PRIMARY | Watts Regulator Company (USA) |
NSN 4820-01-520-4790 is a Valve,vacuum Breaking, manufactured by Watts Regulator Company, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-520-4790 has 1 manufacturer part number on file: 800M4-QT .750 IN (Watts Regulator Company).
Key specifications for 800M4-QT .750 IN: Flow Control Device: DISK, FLAT; Temp Rating: 140.0 FAHRENHEIT DEGF; Temp Rating: 33.0 FAHRENHEIT DEGF; Second End Relationship with First End: IDENTICAL. 12 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.