Does your pump have the right type of coupling for a variable speed application?

Due to ASHRAE energy code requirements, variable speed pumping applications are very common in commercial hydronic heating and cooling systems. Consulting engineers that specify base-mounted, flexible coupled, type pumps need to be sure they specify that the pump have a coupling suitable for variable speed applications. A standard “spider type” coupling is not the best choice for this application. In variable speed applications, this type of coupling looses its ability to accommodate misalignment. This will also eventually wear away the teeth on the element. Instead, a coupling similar to the Woods “Dura-Flex” model should be used. This is a much more forgiving coupling when it comes to shaft misalignment. The center element is bolted to the outer hubs which makes it easy to assemble and eliminates the need for precision alignment.

TACO FI series pumps ship standard with variable speed couplings.