An industry valve works by closure member, like disc, ball, wedge to finish its job. The ball valves have the balls rotary in the valve body to control the flow, gate valve have its wedge to shut-off the port, butterfly valve、check valve andglobevalve use the discs to control the opening and closure of the valves etc.
The closure member of the valve performs various kinds of mechanical motion during operation. Accordingly, the industry valves are grouped as follows: