... 3.Standard: DIN, BS,ISO etc 4.With CE & ISO certificate Flange centerline butterfly valve is designed by DIN(BS) standard from DN50 ... (centerline double flanged butterfly valve), D343(double eccentric flanged butterfly valve), Grooved end type, Double disc wafer check valve, Resilient flapper check valve, Eccentric plug valve, Half-lug or no-lug ...