Introduction of pipe fittings
  Steel fittings are all pressure-bearing fittings. According to the different processing technology, it is divided into four categories, namely butt welding pipe fittings (divided into welded and non-welded pipe fittings), socket welding and threaded pipe fittings, and flange pipe fittings.

Related applications
   China is already the world's largest producer and consumer of building materials. The output of major building materials such as cement, flat glass, building sanitary ceramics, stone and wall materials has been the world leader for many years. At the same time, the quality of building materials products has been continuously improved, the consumption of energy and raw materials has been decreasing year by year, various new building materials have been emerging, and building materials products have been continuously upgraded. Cangzhou has a solid foundation for the pipeline equipment manufacturing industry. There are more than 3,200 production enterprises, including 222 enterprises above designated size (with sales income of more than 5 million yuan) and 124,000 employees. The main products are seamless steel pipes of various calibers such as special steel, stainless steel, carbon steel, low, medium and high pressure boiler pipes, oil drilling pipes and other steel pipes; various tees, crosses, valves, reducers and other elbow fittings ; All kinds of stainless steel flanges, forged flanges; all kinds of pipe racks, instruments, oil blowout preventers and other pipe fittings; all kinds of polyethylene pipes, polypropylene pipes and other plastic pipes, a total of 16 categories of more than 370 varieties of more than 3,500 kinds Specification. The manufacturing process mainly adopts hot-rolled straight seam welding, spiral double-sided submerged arc welding, forging, forging, intermediate frequency pushing, cold forming, hot extrusion, etc. The maximum processing diameter of the pipeline is 2020 mm. Products are widely used in municipal, petrochemical, west-to-east gas pipeline, shipbuilding and nuclear power engineering fields, with an annual design processing capacity of 25 million tons. In 2010, the industrial added value of enterprises above designated size reached 13 billion yuan, a year-on-year increase of 31.7%, accounting for 16.1% of the added value of all enterprises above designated size. Cangzhou's pipeline equipment manufacturing industry is moving towards the goals of "Three Ups" (upscale, upscale, upscale equipment) and "Three Highs" (high, medium and low grades, high pressure, and high added value), and strive to promote the manufacturing capacity of pipeline equipment to reach 30 million tons . Cangzhou will become a well-known "pipeline equipment manufacturing and R&D base" and "pipeline equipment capital" at home and abroad. The "Eleventh Five-Year" planning infrastructure investment has reached the middle stage. The explosive growth of infrastructure construction investment such as roads and railways and the steady growth of ordinary civil construction investment have made the construction industry in a booming stage. At the same time, in the context of building an energy-saving society and the country's ability to strengthen independent innovation, the theme of energy-saving and technological innovation will be the hotspot of the industry's development.

standard system
   There are two main international pipe flange standards, namely the European pipe flange system represented by German DIN (including the former Soviet Union) and the American pipe flange system represented by American ANSI pipe flanges. In addition, there are Japanese JIS pipe flanges, but they are generally only used for public works in petrochemical plants, and have little impact internationally. Now the pipe flanges of various countries are introduced as follows:
1. European system pipe flanges represented by Germany and the former Soviet Union
2. American system pipe flange standard, represented by ANSI B16.5 and ANSI B 16.47
3. British and French pipe flange standards, each of which has two sleeve flange standards.
To sum up, the international common pipe flange standards can be summarized into two different and not interchangeable pipe flange systems: one is the European pipe flange system represented by Germany; the other is represented by the United States American pipe flange system.
IOS7005-1 is a standard promulgated by the International Organization for Standardization in 1992. This standard is actually a pipe flange standard that combines two series of pipe flanges from the United States and Germany.