... diameter As a first manufacturer of tank polishing machine in China ,BOAO has the patent for almost ten years ... . We are prossional in polishing tanks,vessel,seal head ,range from 500mm~ ... can be as high as 0.28 μ m4.simple in structure, easy coperation, economical and parctical.DP Multifunction Polishing ... wire 380V/50Hz Air supply0.4-0.6MPa Multi-function polishing machine