Structure characteristics: 1.The valve adopts two kinds of sealing, e.g. balance double valve seat and single valve seat with reliable closedown and long life. 2.There is always condensate water available in front of the valve with reliable water sealing and non-leakage of steam. 3.No noise before operation in favor of environmental protection. 4.At the beginning of ventilation, all the valves start and low-temperature condensate water and air are rapidly expelled to greatly shorten the start time for equipment. 5.Internal components is made of stainless steel, corrosion and cavitation erosion proof.