Profile: Wenzhou Best Valve & Pipe Fitting Co.,Ltd specializes in providing different kinds of industrial valves, including ball valve, gate valve, check valve, and globe valves. Our various products are widely used in petrochemical industry, petroleum refining, nuclear power, chemical industry, metallurgy as well as mining, medical industry, food industry, national defense, military and urban construction sectors. BST Trunnion ball valves are quarter-turn valves used to stop or start the flow of a media in a pipe. The most common type of ball valve has a free floating design, so the trunnion type is a design change.