STAC, Inc. is the leading provider of Thermaflow hydraulic drive systems for the propane industry. Hydraulic drives provide a safe, convenient way to reduce downtime and extend the life of the vehicle. Also, because of today's vehicle emission standards, STAC eliminates the headache of trying to weave a driveshaft to the product pump. STAC's innovation also helps reduce or eliminate cavitation while stabilizing the flow. Increasing your pumping efficiency gives you the opportunity to make more money.