Globe valve is also called the sectional door way, belongs to the forced sealed valve, the valve is closed, must be pressure on the disc, to force a sealing surface does not leak.When the medium from the disc below to the valve, the operating force to overcome resistance, is stem and packing friction with the thrust produced by medium pressure, close the valve force stronger than open the valve, so it's bigger, the diameter of the stem or stem top bending failure happens.According to the connection mode is divided into three types: flange connection, threaded connection, welding connection.From sealed valve, cut-off valve is replaced by the disc above the medium flow direction into the valve cavity, in the medium pressure at this moment, close the valve of the force is small, and the strength of the valve, the valve stem diameter can be reduced accordingly.At the same time, in the role of media, this kind of valve is tight.Valve in China "three for" regulation, the flow of cut-off valve, shall be applied.The cut-off valve opens, the opening of the disc height, for 25% ~ 30% of nominal diameter. Flow has reached maximum, said valve to full open position.So stop valve fully open position, should be determined by disc's schedule.
Cut-off valve, stop valve, Globe valve) of the opening and closing is plug valve, sealing the above a plane or cone, disc along the seat of the center line of linear motion.Stem form of exercise, (generic name: non-rising stem), there are also lift rotating bar type can be used to control air, water, steam, all kinds of corrosive medium, mud, oil, liquid metal and radioactive medium such as various types of fluid flow.Therefore, this type of globe valve valve closure is very suitable for as a cut or adjust and throttling.Due to open or close the valve stem travel relatively short, and very reliable cutting function, and due to the change of his seat and disc stroke proportional relationship, is very suitable for the traffic regulation.
