A process for continuously providing superheated liquid to a chemical process vessel by providing a first heating device capable of heating an entire liquid effluent stream from the vessel, the first heating device receiving the entire liquid effluent stream from the vessel and returning a heated liquid stream to the vessel; filling a similar second heating device with liquid from the liquid effluent stream prior to applying any heat to the second heating device; heating and increasing the liquid effluent stream supplied to the second heating device while decreasing the liquid effluent stream provided to the first heating device until the second heating device is receiving and returning all the heated liquid stream to the vessel, while adjusting heat to the devices as needed to maintain the heated liquid below the flash point and maintain the desired total amount of superheated liquid provided to the vessel.