There are many of advantages of Seamless Steel Pipes

The largest benefit to using seamless steel pipe is the increased pressure ratings. When steel pipe is rolled and welded, the weakest point in the pipe is the welded seam. A seamless steel pipe does not have a seam, so the tensile strength is uniform around the entire circumference of the pipe. Steel pipe has nominal pressure ratings that are based on the tensile strength of the alloy (mixture of metals) and the wall thickness of the pipe. Using seamless pipe is more expensive but allows for smaller wall thicknesses and pipe weight, which can affect design and costs.
Because seamless steel pipe is a continuous extrusion of the alloy, it takes advantage of true roundness of the circumference. Welded seam pipe invariably is not as round in the cross sectional area as a seamless steel pipe because the welded pipe is wrapped around another form before welding. The welding adds heat, and the equipment adds stress to hold the pipe together. This process introduces variables that allow for warping of the roundness. Seamless pipe maintains the round cross-section, which is important during installation and the addition of pipe fittings.

Although seamless pipe is the most expensive steel pipe, it is the most reliable with the fewest failure points. Because of this, pressure calculations are easier to perform because the weld quality is taken out of the equation. Another advantage to using seamless steel pipe is its strength under loading. Empty pipe has a certain weight that must be supported over long spans. When that pipe begins transporting material, the weight of the material must also be taken into account. Seamless steel pipe has strength benefits compared with welded pipe. Most pipe failures and leaks take place at the welded seam.