A shell and tube heat exchanger is a class of heat exchanger designs.
It is the most common type of heat exchanger used in food industries and other large chemical processes, and is suited for higher-pressure applications.
These types of Heat exchangers are having shell.
As its name implies, this type of heat exchanger consists of a shell (a large vessel) with a bundle of tubes inside it. One fluid runs through the tubes, and the second runs over the tubes (through the shell) to transfer heat between the two fluids. The set of tubes is called a tube bundle, and may be composed by several types of tubes: plain, longitudinally finned, etc.
For this purpose seamless/ERW or Rolled pipes are used for shell. And Seamless tubes are used for Tubes.