Pipe is made from many different materials depending upon the properties of the media that is being transported. For example, pressure is used to transport potable water to it’s end user. So, a pipe that has high pressure rating (typically greater than 150 psi) must be used. It would also be desirable for the pipe to have a smooth interior to promote good flow.
Engineering companies have materials engineers to determine materials to be used in piping systems. Most pipe is of carbon steel (depending on service) is manufactured to different ASTM standards.
Carbon steel pipe
Carbon-steel pipe is strong, ductile, weldable, machinable, reasonably, durable and is nearly always cheaper than pipe made from other materials. If carbon-steel pipe can meet the requirements of pressure, temperature, corrosion resistance and hygiene, it is the natural choice.
Iron pipe is made from cast-iron and ductile-iron. The principal uses are for water, gas and sewage lines.
Plastic pipe may be used to convey actively corrosive fluids, and is especially useful for handling corrosive or hazardous gases and dilute mineral acids.
Alloy and Stainless pipe
Other Metals and Alloys pipe made from copper, lead, nickel, brass, aluminium and various stainless steels can be readily obtained.
These materials are relatively expensive and are selected usually either because of their particular corrosion resistance to the process chemical, their good Heat Transfer, or for their tensile strength at high temperatures. Copper and copper alloys are traditional for instrument lines, food processing and Heat Transfer equipment. Stainless steels are increasingly being used for these.