PILOT OPERATED SAFETY VALVE AND OPERATING METHOD

摘要

PURPOSE: A pilot operated safety valve and an opening and closing method thereof are provided to improve reliability of the safety valve by improving operation accuracy. CONSTITUTION: A pilot operated safety valve comprises a main chamber(100), a main opening and closing valve(200), an auxiliary chamber(300), an auxiliary opening and closing valve(400), and an elastic unit(500). The main chamber has first and second chambers(110,120). The first and second chambers are divided by a first diaphragm(130). The main opening and closing valve is connected to the first diaphragm and opens and closes a gas inlet(1a) of a gas tank(1). The auxiliary chamber has third and fourth chambers(310,320) divided by a second diaphragm(330). The auxiliary opening and closing valve is connected to the second diaphragm. The elastic unit supports the auxiliary opening and closing valve.