... CE certificate 3,good serive 4,do OEM double flanges rubber expansion Table of Materials 1,Main body: Polarized rubber2, ... , Cast Iron, Ductile Iron and so on Technical Consition Nominal core diameterDN32~DN300(11/4"~12")DN350~DN500(14"~20")Working ... . Table of Main Parameters of Nominal Core Diameter, Length, Displacement Value and Flange Nominal core diameterDNLength L (mm)Axial displacement(mm ...