The main difference: 1. dark bar gate valve flange to enhance screw rotation only up and down without moving, exposed only one pole, Shanghai and Shanghai Valve Manufacturing Co., Ltd., and its nut is fixed to the gate, through the screw rotation to enhance the gate, no visible door frame; rising stem gate valve flange to enhance screw is exposed, Shanghai Guanlong valve Machinery Co., nut against the hand wheel and is fixed (non-axial rotation does not move) by turning the screw to enhance the gate, screw and gate only relative rotation without relative axial displacement, appearance of a door-shaped bracket. 2 dark bar valve screw is invisible, and the next shot is able to see the screw. 3. The dark bar valve stem when the switch is connected with the steering wheel and relatively immobile, Guangzhou Kaiheng Valve Co., Ltd., which is obtained by rotating the stem at a fixed point to drive the valve lift and lower shutters up to complete opening and closing a. Rising stem valve is used to raise or lower the valve stem and the steering wheel through a threaded drive. After the turbine, double flanged butterfly valve flange butterfly doors closed Note shutting, Shenzhen valve, the pressure medium or ambient temperature changes, thermal expansion causes the valve member between the gate and the seat becomes large. This force is reflected in the stem threads, it is difficult to open the valve again, the torque required to open the valve (that is applied to the stem nut torque) is generally higher than the torque required to close the valve It is far greater. Tianjin Tanggu Watts Valve Co., Ltd. | Shenzhen valves | valve out of Hong Kong, the Hong Kong valve provided by the Dongguan Science and Technology Co., Ltd. Valve Co., Ltd., Dongguan Ming Kong (www.gdmgfm.com) strong, credible, butterfly and other industries in Dongguan, Guangdong has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead valve and you work out of Hong Kong into the brilliant, for a better future!