Caleffi's644 Series motorized ball zone valves provide zone control for applications requiring
high flow rates (to 13 Cv) and high close-off pressures (to 150 psi).
Standard two-way and three-way mixing and diverting models
are available as well as a unique three-way bypass configuration that switches
between primary and bypass flow ports to prevent pump dead heading.
A durable, energy efficient 24 volt, three-wire
actuator provides traditional two-position control action, or can be combined
with any three-wire floating controller for outdoor reset on radiant systems. High
electrical efficiency allows for nine valves on a standard 40 VA transformer.The
644 Series zone valves come in ½”, ¾”, and 1 in. sizes with NPT or sweat union connections.