Welding is an effective way of connecting pipes. Pipes have many types, and are grouped into two groups of pipes. Namely: Types of pipe without connection: manufacture of pipelines without welding joints; type of pipe with connection: manufacture of pipe by welding process.

Pipe welding pays attention to the diameter of a pipe. For example, welding pipes that have a large diameter. Welding that can be applied is using SMAW-SAW and other methods. The joint welding is usually used on pipes with a diameter of at least 10 mm, for example in welding oil refinery pipes, top and bottom boiler drums and others. In the welding process must pay attention to the test of hardness and tensile strength, heat treatment process, post-weld heat treatment. Specific heat treatment process to reduce the residual stress that occurs due to the welding process.

The structure of the new pipe material generally consists of: Carbon steel, Carbon Moly, Galvanees, Ferro Nickel, Stainless Steel, PVC or Paralon, Chrom Moly, Copper. Meanwhile, pipe materials specifically consist of: Vibre Glass, Aluminum, Wrought Iron, Cooper, Red Brass, Nickel chrome iron or inconel. The use of pipes is widely applied to meet industrial needs, for example for: gas, oil, boiler drums, steam flow pipes, and many others.