The purpose of the device is to control the flow of potable water based on the pressure of
hydronic water from a hydronic system. The device performs this hydraulically and has integral
cross contamination protection between the potable and hydronic water. This device is typically
installed in conjunction with a heat exchanger and a part of a hydronic system loop.

This device consists of a single potable cold water supply inlet and outlet, and a single hydronic
supply inlet and outlet, a means of dynamic flow control, an atmospheric vent, and two sets of
three dynamic seals between the potable and hydronic flow paths.