I. Product Overview residual pressure valve is required and there is a clean environment, supporting the use of air purification equipment. Using the residual pressure valve, can achieve the following functions: indoor positive state, making the smooth discharge of excess air in order to maintain the stability of the indoor and outdoor positive pressure; indoor vacuum state, automatically shut down, avoid outdoor dirty air back to indoors. Indoor fire, after extinguishing gas spray, as pressure relief valve: indoor air export, maintain a balanced pressure; avoid indoor air pressure suddenly too large, resulting in deformation of the fire doors and squeeze effect. Our residual pressure valve has a novel structure, beautiful appearance, easy maintenance, etc., can be used in the engine room, electrical plants, a variety of clean rooms, laboratories, and other various clean process environment. Second, the working principle of the residual pressure valve is mounted on the wall, when the chamber pressure exceeds the set pressure, the valve will automatically open the residual pressure valve, making the smooth discharge of excess air to maintain positive pressure indoor and outdoor. Hammer position can be adjusted according to the required air volume environment, the pressure differential. When the room is not positive, or partial pressure greater than outdoor indoor pressure (wind, etc.), residual pressure valve body closed, avoid outdoor dirty air back into the room. Indoor fire, the extinguishing gas after discharged, under pressure, the residual pressure valve opening degree of the valve reaches the maximum, will rapidly exhaust the room air, maintain a balanced pressure, play a role in relief.