We manufacture concentric butterfly valve in China, also named center-line butterfly valve. The body materials are cast iron, ductile iron, carbon steel WCB, WCC, stainless steel CF8, CF8M, CF3, CF3M, the pressure PN6, PN10, PN16, PN25, Class 125, Class 150 for low temperature situation. The design standards are GB/T 12238, API 609, EN593, Face to Face as per DIN3202-K1; EN558-1 20 Series; BS5155; MSS SP-67.