Tubing plates, which are circular steel plates with holes slightly larger than the outer diameter of the tubes, serve as round steel components in heat exchangers for fixing tubes and sealing the medium. They are a type of fitting used to穿管并焊接固定，performing such a function.

The precision of tube plate processing, particularly the spacing and tolerance of tube holes, diameter, perpendicularity, and smoothness, greatly affects the assembly and operational performance of the listed chemical equipment.

Bolted flanges for pressure vessels of categories three and four require higher precision. Traditional hole processing methods include fitter marking and arm drill boring. With the large-scale of chemical equipment, the diameter of the flanges is increasingly larger, and the thickness is also gradually thicker. The processing of flanges has introduced CNC technology, and CNC drilling machines are commonly used for initial boring in conjunction with arm drills for hole processing. High-precision hole processing using machining centers is gradually being accepted by some large enterprises. There is an increasing demand for heavy-duty flanges in the nuclear power, seawater desalination, and central air conditioning heat exchanger fields.