Series SD-3 Dual Check Valves with Atmospheric Port & Strainer for Carbonated Beverage, Coffee and Tea Machines, tehe watts SD-3 is used to prevent the reverse flow of polluted water in a domestic(potable)water line.

Boiler Water Supply Valve - the Watts 911S "Dual Valve" gets it's nickname because it is a combination back-flow preventor and (PRV) pressure reducing valve. Watts 911S provides safe make-up water, preventing a backflow condition. Designed for use with a residencial size hydronic (water) heating boiler, water pressure is reduced to 15 psi, and is adjustable within a range of 10-25 psi. Watts 911S also prevents a harmful backflow condition. Watts 911S is a 1/2 Inch copper Sweat X 1/2" FIP connection.

Legend Valves Dual Check Backflow Preventer

2SVBFDPA04, Z-Vent 4" Universal Appliance Adapter. Adapts Z-Vent to Laars, Bosch, Nortec, Takagi, Paloma, Rheem, Modine and Reznor flue outlets. Adapter is a "3-in-1" Cat III fitting that incorporates a vent pipe coupling, back-flow preventer and condensation drain tee with 3/8" nipple. Shown with High Temperature drain Line attached.

Legend Valves Backflow Preventor Atmostpheric Vent

Legend Valves Backflow Preventors Atmospheric Vent

Legend Valves Vacuum Breaker 3/4" (T-553)

Legend Valves Vacuum Breaker Chrome 3/4" (T-553C)

TOILET FILL VALVES
ANTI-SIPHON - ADJUSTABLE
Adjust. Hgth. Ins.=9 to 14

Series 9D Dual Check Valves with Intermediate Atmospheric Vent, prevents the reverse flow of hot or cold polluted water from entering into the potable water supply. Select 9D-M3 1/2" FIP or 9D-M2 3/4" FIP. The Watts "9D" can be used under continuous pressure.