check valve.swing type,flange type. Sizes:DN50~DN600. check valve,swing type,flange type.Design & manufacture standard: API6D, ANSI/ASME B16.34, BS1868. ... Face to face dimensions: ANSI/ASME B16.10.Flange ... , A105, CF8(304), CF8M(316), CF3(304L), CF3M(316L), etc. check valve