... structure, less scrap, eddy-current test 1)various types of dental patterns, its heat transfer coefficient can be 2.5 ... surface. It has a homogeneous and compact structure and features of high dimensional precision, high heat-exchange efficiency, easy welding, ... 10~0.300.30~1.0510~1000~5030~100Nominal dimension of tubes with ordinary ridge patternNo. SizeDODdIDTWbottom wall thicknessHfaddendum heightTWT ...