Study on hole processing technology of low alloy steel tube-sheet
In view of the hole processing of low alloy steel tube-sheet,the quality difference of tube holes formed by one time in the common tube hole processing machine in China,the changes in sealing property and pull-out force of 10#+16Mn expansion joints with initial clearance of 0.36 mm and 0.26 mm under the same hydraulic expansion force were compared by tests.It is pointed out that the limit value B of the width between continuous holes with changes in the thickness of tube sheet in GB/T 151-2014 has been backward,and should be adjusted when the standard is updated.It is found that the surface roughness of the hole should be adjusted according to the outer surface roughness of the exchange tube,the design requirements for the tube bundle sealing performance and the pulling force.With the improvement of processing technology in Chinese equipment manufacturing industry,the processing machines for tube sheet holes should be selected from CNC drilling machine,machining center and CNC deep hole drilling machine,and the radial drilling machine should be phased out gradually.
hole processing of tube-sheetwidth between continuous holestube hole roughnessexpansion jointssealing performancepull-out force