Carbon steel pipe material is widely used in various industries such as petroleum, chemical, mechanical, metallurgy, food and so on. Carbon steel pipe can withstand high pressure, can resist high temperature, used for transporting steam, compressed air, inert gas body, gas, natural gas, hydrogen, oxygen, acetylene, ammonia, liquid ammonia, water, oil and other media. Since the carbon steel has a certain corrosion resistance, so carbon steel pipe can be used to transport at room temperature alkali solution and corrosion medium "after heat treatment to eliminate welding stress force, carbon steel pipe can also be used to transport the caustic]. The carbon steel pipe can also be used for conveying other corrosive media, such as the lining of the corrosion resistant coating, or the corrosion resistant material lining, such as lead and rubber. 2 low alloy steel tube Low alloy steel pipe is generally made of pearlite heat resistant steel, which is characterized by high strength and heat...