The 91000XT Tank Thermostat isspecifically designed to control thetemperature of heaters, treaters andseparators within the petroleum industry.It is entirely self-contained, requires noexternal power source, and is the mostwidely preferred unit of its kind. Wheninstalled in a treater, the normally openvalve will automatically close off the flowof gas as temperature increases, therebyregulating temperature within the treater.The Trerice 91000XT is ruggedlyconstructed with a heavy duty, die castaluminum actuator housing and fullyenclosed bellows assembly. Its singleseated, cast-iron valve body is fittedwith a stainless steel plug assemblyand soft seating o-ring to providetight shut-off.