The ECONO/HAT/RA valve from Therm-Omega-Tech, Inc. (Warminster, PA) is suited for use with centrifugal pumps that are used to pump water in high-rise buildings. It requires no wiring to install or electrical power to operate, instead making use of a thermal actuator that continually senses the temperature of the water in the pump. When water temperature rises above the desired limit, the actuator causes the valve to open. A small sample of water then flows past the sensor. If the water is above the acceptable range, the valve will continue to modulate open until the overtemperature water returns to the safe range, then the valve then modulates closed.