Dole valves are used to restrict the output of water through a line to a specified gallons per minute. Consequently, this is a great tool to regulate flow rates through multiple heat pumps or ground loop circuits. Multi-family home situations with many smaller water-to-air heat pumps are a great example of where this valve is useful.
The Dole Valve has become a recognized industry standard name for flow regulators in the water treatment and water conservation industries.
Pipe size connections for all valves are 1″ FPT.