ERW Piping

ERW or Electric Resistance Welded pipe are used for many different applications, as it is the most readily  available and economical type of mechanical tubing. There are two different types or processes to create ERW  tubing. You have, CREW or Cold Rolled ERW and you have HREW or Hot Rolled ERW. With each type of Electric  Resistance Welded pipe, there are different steps that go into creating the tubing, as well as different uses for  each ERW tubing after it is created.

ERW pipe initially starts out as a flat pieces of steel, and then rolled into a tube shape. Without overlapping, the  seam is then welded using a process called “Electric Resistance”. You may now understand where ERW tubing gets  its name! During the process of creating ERW tubing, the piping may either be hot rolled or cold rolled, which has  a drastic change on the outcome of electric resistance piping. Also created from the electric resistance welding  process is DOM tubing.

HREW or Hot Rolled ERW is rolled at high temperatures. The high temperatures allow the HREW tubing to be  formed easily. Because the process causes the HREW pipe to be more malleable, it reduces its strength compared  to CREW piping. Because the strength is less than that of CREW tubing as a result of the high temperatures, HREW  is usually cheaper than that of CREW.

CREW or Cold Rolled ERW follows the same process as hot rolled ERW, except it is done at room temperature. As  a result CREW piping has a stronger yield strength than HREW. Creating these pipes at room temperature makes  the lattice structure withing the steel tighter, along with a smother surface. Because of the strength and  smoothness of CREW piping, it is much better to work with that HREW, as it has a greater tolerance.