Seamless Pipe

Seamless Pipe is usually made from a solid round metal billet which is heated and pushed or pulled over a form until the material is shaped into a hollow tube. The Seamless Pipe is then finished to dimensional and wall thickness specifications.

Seamless Pipe is mostly used to carry high pressure gas or fluid within the Oil, Gas, Filtration, Refrigeration, Refining, Petrochemical and Offshore Industries.

EFW Electric Fusion Welded Pipe

EFW is Electric Fusion Welding, a welding process without filler.

Also, EFW (Electric Fusion Welded) Pipe in terms of ferrous material specifications under ASME implies filler metal added (SA-691 and SA-671).

There are three processes for metallic pipe manufacture. Seamless (SMLS) Pipe is formed by drawing a solid billet over a piercing rod to create the hollow shell.

Seamless Pipe provides the most reliable pressure retaining characteristics, and is often more easily available than welded pipe.

Welded, Electric Resistance Welded (ERW) and Electric Fusion Welded (EFW) Pipe is formed by rolling plate and welding the seam. The weld flash can be removed from the outside or inside surfaces using a scarfing blade. The weld zone can also be heat treated, so the seam is less visible.

Welded Pipe often has tighter dimensional tolerances than seamless, and can be cheaper if manufactured in the same quantities. Large diameter Pipe (about 10 inches or greater) may be ERW, EFW or Submerged Arc Welded (SAW) Pipe.

ERW Electric Resistance Welded Pipe

ERW or Electric Resistance Welded Pipe is produced from individual sheets or continuously from rolls of skelp. ERW Pipe is cold formed into a cylindrical shape rather than hot formed. An electric current rather than a flame is used to heat the edges of the strip for the fusion weld.

ERW Pipe is subject to numerous finishing operations. ERW Pipe is primarily used as API Line Pipe for the transmission of gas and oil. It is also used for the transmission of water, under AWWA specifications, as piling and slurry pipe and in mechanical applications.

DSAW Double Submerged Arc Welded Pipe

DSAW or Double Submerged Arc Welded Pipe derives its name from the welding process wherein the welding arc is submerged in flux while the welding takes place. Both inside and outside welds are required and are usually accomplished in separate processes, hence the word "double." These separate welds consume a portion of the other, resulting in a single high quality weld nugget.

DSAW Pipe is normally produced in double random lengths with square ends or beveled for welding. DSAW Pipe is used in high-pressure gas and oil transmission lines (both onshore and offshore), structural members and Pipe piles.

Forged Pipe

Forged Pipe is pipe which is made from bar. This could be a piece of Pipe with a non standard wall thickness, specially made from bar where billet is the base material.