Answer: Generally, stainless steel general chemical insulated tank trailers (MC307 or DOT407) are equipped with a heat panel. The heat system design uses either a dimple or channel panel. The heat panels are designed for steam (up to 150 psig) and tractor in-transit heat (3.5 to 6 GPM at no more than 10 psig). Steam is usually connected at the rear of the trailer and in-transit is at the front of trailer. Some carriers have designed stationary heating systems for use with a parked trailer. The stationary heater is similar to a home water heater with a pump and closed-loop system. The water heater tank contains the same coolant as the tractor. The coolant is pumped to the heat panel and returns to the water heater. The connections at the front of the trailer would be used with the stationary heater. When using in-transit, the tractor coolant is temperature is approximately 175 to 200 deg F based on the specific tractor. Several precautions should be taken with heating. Always make sure the heat panel is filled with coolant using in-transit heat. Never heat/steam an empty trailer. When you steam a trailer, you will lose your coolant. If using a stationary heater, minimize the hose length from the heater to the trailer, make sure the closed loop system is fully charged with coolant and monitor the circulating coolant temperature.