US Patent 7770592 Valve with freeze-proof heated valve seat

A valve comprises a valve body having a fluid inlet and fluid outlet, a valve seat located in the valve body between the fluid inlet and a fluid outlet, a valve member movable towards and away from the valve seat for controlling the flow of fluid from the fluid inlet to the fluid outlet, and a PTC heater in thermal contact with the valve seat for heating the valve seat. The heater is integrated in the valve in a manner where the valve seat is used as an electrical conductor to facilitate operation and assembly of the valve, and a unique valve construction is provided for enabling self-draining to avoid accumulation of water or other liquid in the valve that might negatively impact performance of the valve.