A properly sized valve prevents noisy operation and premature valve failure. A valve that is too large can lead to problems such as wire draw under low flow conditions. In general, the minimum flow through a water pressure reducing valve should be 10% to 15% of the maximum flow rate desired in the system. Pressure reducing valves should be selected based on the flow and pressure ranges listed, not by the size of the pipe they will be attached to. You should select a regulator whose operating pressures fall within the middle of its rated range.
Pressure valves including Watts Pressure Valves, Taco Pressure Reducing Valves, and Bell & Gossett Pressure Reducing Valves can be found at www.supplyhouse.com
