Proportional Flow Controller, with Protection from Cross Contamination, for use in Drinking Water Installations

Proportional Flow Control Devices are commonly found in European hydronic systems. Typically, these product are installed as a part of an integrated system to balance flow into both sides of a double-wall heat exchanger. One side increases the cold water supply temperature to supply domestic hot water, the other side receives hydronic hot water that is cooled to supply the hydronic loop. The device controls the flow of water of both the cold water supply and the hydronic loop based on the temperature and flow requirements of the hydronic loop. This helps minimize dead legs in the hot water distribution system to supply fittings. It is also important that these device be adequately equipped with a means to prevent contamination of the water supply. This standard adapts translated requirements from DVGW VP 201 Testing Specification for Flow-rate control devices with double diaphragm and safety valve and ASSE 1012 for Backflow Preventers with intermediated Atmospheric Vent to provide adequate protection of the potable water system.