254SMO has good resistance to uniform corrosion. Especially in halide-containing acids, this steel is superior to ordinary stainless steel. Its C content is <0.03%, so it is called pure austenitic stainless steel (<0.01% is also called super austenitic stainless steel). Super stainless steel is a special stainless steel, which is first different from ordinary stainless steel in terms of chemical composition, and refers to a high-alloy stainless steel containing high nickel, high chromium and high molybdenum. Among them, the more famous is 254SMo containing 6% Mo, this kind of steel has very good local corrosion resistance,under the conditions of seawater, aeration, gaps, and low-speed erosion, it has good pitting resistance (PI≥40) and good stress corrosion resistance, and is a substitute material for Ni-based alloys and titanium alloys. Secondly, in terms of high temperature resistance or corrosion resistance, it has more excellent high temperature resistance or corrosion resistance, which is irreplaceable by 304 stainless steel. In addition, from the classification of stainless steel, the metallographic structure of special stainless steel is a stable austenitic metallographic structure.Because this special stainless steel is a high-alloy material, it is quite complex in the manufacturing process, and generally people can only rely on traditional processes to manufacture this special stainless steel, such as pouring,forging,calendering and so on. The end cap on a pipe cap pressure vessel is a main pressure-bearing component of the pressure vessel. Its function is to seal.Firstly, it serves as the top and bottom of a cylindrical pressure vessel. Secondly, if the pipeline ends and is not intended to extend further, then a pipe cap is used to seal the pipe through welding. Products similar to the function of a pipe cap include blind flanges and pipe caps, but those two products can be disassembled. In contrast, once a pipe cap is welded, it cannot be disassembled. Associated fittings include pressure vessels, pipelines, flanges, elbows, tees, and crosses.