Multiple Floors: Because the system is pressurized, the number of floors in a home is not taken into consideration in sizing the circulating pump. The pump has only to produce continuous flow at a pressure sufficient to overcome the friction losses created by the piping in the house water supp...
and many times amounts to only a few watts. Yet the pumps must be designed as thick-walled cast iron structures because of forces exerted on the pump housings the pipes which are subjected to thermal expansion and contraction forces which may reach extremely high values. Circulating pumps in ...