The anticorrosion bend is bent with a set of bending dies, which can be divided into two kinds of processes: cold and hot. Either machine or pipe, most of which use bend, mainly for oil, gas, infusion, etc. The main production equipment of anticorrosive bend is pipe bender, and the pipe bender can be divided into CNC pipe bender, hydraulic pipe bending machine and so on. Anticorrosive bend demand request according to the function of the heat pipe, the pipe diameter and wall thickness size, hot bending equipment and control techniques and other detailed conditions to select different hot bending process, and develop appropriate hot bending process parameters, talents bend ensure to produce qualified bend.

There are two main systems for international flanges, namely the European tube flanges system represented by German DIN (including the former Soviet union) and the American tube flange system represented by the American ANSI tube flange. In addition, there are Japanese JIS tube flanges, but in petrochemical installations, they are generally used only for public works and have little international impact. Now the country's flanges are introduced:

1. European system tube flanges represented by Germany and the former Soviet union

2. Standard of American system tube flange, represented by ANSI B16.5 and ANSI B 16.47

3. British and French flanges standard, each of which has two pipe flange standards.

To sum up, the international standard of tube flanges can be summarized into two different and uninterchangeable pipe flanges system: a European tube flange system represented by Germany; The other is a system of American tube flanges represented by the United States.