Caleffi Backflow Preventers
These units are dual check continuous pressure backflow preventers with atmospheric vent used for boiler feed lines to prevent backflow when supply pressure falls below system pressure.
| ID Number | Union Type | Outlet Size | Price |
| 573403A | 1/2" NPT Female Union | ---- | $99.80 |
| 573503A | 3/4" NPT Female Union | ---- | $101.00 |
| 573409A | 1/2" Sweat Union | ---- | $117 |
| 573009A | 1/2" Sweat Union Inlet | 1/2" Female Outlet | $117 |
| 573002A | 1/2" NPT Female Inlet | 1/2" NPT Female Outlet | $117 |
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