What is the diameter of the water pipe of Elantra water tank?

The function of the engine warm water pipe is to let the engine coolant flow into the warm water tank. The heating source of this air conditioning heating system is available. One is to use engine coolant as the heat source (currently used by most vehicles), and the other is to use fuel as the heat source (used by a few middle and high-grade vehicles). Do you need to install a throttle valve in the car warm water pipe? The automobile warm water pipe is the place where antifreeze flows when the automobile is cold started. When the water temperature rises, the thermostat opens and the antifreeze circulates in the water tank. So when the car starts cold, antifreeze only flows in the warm water tank.