Welded Pipe
Suitable for applications that require not very high pressure, because the production process uses a welding method the joints are joined together to form a pipe. Which is likely to cause cracks in the joints the most popular method is Electric Resistance Welding (ERW) which is a compression welding method. As the seam is fused by electric heating without arcing, the resistance to electric current heats the edges of the steel to a temperature between 1200ºC and 1400ºC and then presses the seams together. The pipes produced by this method are straight seams (Longitudinally welded seams)
Seamless Pipe
Suitable for high-pressure applications high heat resistance is a job that requires high safety. The general production process is to heat a solid shaft. Then drill through the solid shaft to make a hollow. And the method of forming seamless pipes is divided into two methods:
- Cold-finished seamless
Cold forming allows the material to undergo permanent deformation at low temperatures without re-crystallization. The advantage is that the workpiece has a smooth, clean surface and a relatively large shadow. More accurate and stronger than before The disadvantage of cold forming is that it creates a lot of stress and strain on the material. And the grain of the metal is easily broken. The method of cold forming for pipes can be divided into 2 methods, namely Cold Rolling and Cold Drawing.
- Hot-finished seamless
Hot forming is the process of deforming a material in an over-temperature environment. in the formation of new crystals but is lower than the melting temperature of the material Makes the metal denser, impurity within the metal will be scattered. Makes the grain of the metal smaller. and the properties of various metals will be improved and looks more homogeneous the disadvantages of the process up this format is oxide is formed on the surface of the workpiece. Causing flakes on the workpiece surface, resulting in an unattractive surface and unable to control the size of the workpiece due to expansion and contraction of metal when heated.
