Application range of titanium and titanium alloy bellows

Due to its excellent comprehensive performance, titanium is called the metal of the 21st century. Although the price ratio between titanium and titanium alloy bellows and stainless steel bellows is very high (about 10:1), the service life of steel equipment is only 2 to 3 years. The service life of the pipe can reach more than 20a, and there is almost no repair cost. From the perspective of long-term and comprehensive economic benefits, it is very cost-effective to use titanium bellows. At present, due to cost and manufacturing technology and other reasons, titanium and titanium alloy bellows can only be used in high-tech industries such as aviation, aerospace and high-energy physics in my country, and are rarely used in chemical, oil refining and other industries. It can be expected that with the development of science and technology in our country, the application of titanium is becoming more and more extensive.

Titanium bellows are generally used in occasions with high performance requirements such as light weight and high flexibility, and are also used in fields with high corrosion resistance requirements. Titanium and titanium alloy bellows have broad application prospects in chemical plants such as saltworks, fertilizer plants, and alkali plants. The chemical industry has high requirements on the corrosion resistance of bellows, and stainless steel can no longer meet the actual production needs. The use of titanium and titanium alloy bellows is a development trend. For example, when alkali plants and chemical plants are used for mother liquor heat exchange, due to the high concentration of CL - in the medium, there is corrosion to stainless steel, and the use of titanium bellows can effectively prevent corrosion. For example, a chemical plant in the United States used (254mm) hydroformed titanium corrugated expansion joints in the pipeline for transporting acetic acid; a Titanium Elbow heat exchanger developed by a company in Beijing for the fields of salt chemical and marine chemical industry has been used in some chemical plants , the effect is good.

In the oil refining industry, the most widely used bellows are wave expansion joints. Bellows expansion joints are widely used in catalytic cracking units in the oil refining industry. The bellows (wave expansion joints) used in the oil refining industry have high requirements for corrosion resistance. The main reason is corrosion damage, which accounts for about 80% of the failure of bellows expansion joints. In recent years, with the increase of corrosive medium content in crude oil, the development of heavy oil catalytic cracking process technology, and the increase of device operating temperature, the working conditions of bellows have become more and more harsh. The corrugated expansion joints in the catalytic cracking unit of the refinery often go through a production cycle, and some months or even several hours of operation will cause corrosion damage and need to be replaced, which seriously affects the safe operation of the equipment and the exertion of economic benefits. A pressing problem for refineries.