Wafer type butterfly valve is one type of central lined butterfly valve, which is one normal type of butterfly valve in need of big quantity. It is mounted between two matching flanges of the piping with bolts & nuts. According to actual piping conditions, wafer type butterfly valve can be manufactured according to different flanges standards, such as ASMEB16.1, EN1092, AS2129, DIN2501, BS4504, JIS10K. Wafer butterfly valve can be mounted on the piping end as exhaust valve.