Metallic Pipe types (SMLS / SAW / ERW)

Seamless Pipe (SMLS)

These pipes are extruded and have no longitudinal seam. There is no weld and is the strongest of the three type pipes mentioned.
The greatest advantage of seamless steel pipes is their increased ability to withstand pressure. The weakest point in a welded steel pipe is the welded seam. But because a seamless steel pipe has not been welded, it doesn’t have that seam, making it equally strong around the entire circumference of the pipe.
It is also much easier to determine pressure calculations without being required to take weld quality into consideration.
Although seamless pipe can sometimes be more expensive than welded pipe, this increased ability to withstand pressure allows you to use pipes that are thinner and lighter, which can help cut down on expenses.

Submerged Arc Welded Pipe (SAW)

Submerged arc welding (SAW) is a process in which the joining of metals is produced by heating with an arc or arcs between a bare metal electrode or electrodes and the work. Submerged arc welded pipes are manufactured from plates, normally rolled and seam welded together.

The welding has a joint efficiency of 0.95.

Electric Resistance welded pipe (ERW)

Electric resistance welded (ERW) pipe is manufactured by cold-forming a sheet of steel into a cylindrical shape. Current is then passed between the two edges of the steel to heat the steel to a point at which the edges are forced together to form a bond without the use of welding filler material.

The welding efficiency is 0.8.

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