Over the years, the steel tubing has been the most common stainless steel product to use in plumbing and pipework applications. But, over time, welding technologies kept advancing that steel tubing manufacturers adopted welded tubing.
But, how exactly do these two differ? In which applications is it best that you use seamless steel tubing over welded tubing and the converse?
Typically, seamless steel tubing does not have longitudinal weld seams. The manufacturing process requires using a joinery mechanism that will force the tubing into a billet. For decades, manufacturers only utilized mechanical joinery when creating seamless tubing.
But, that has been changing now to include automatic rolling and rotary piercing to produce seamless tubing. In this, they heat and work on round conditioned steel bars. That increases the malleability of the steel material.
You now can form, with ease, hollow billets when the heated steel flows around piercers of the required diameter. Further sizing follows by rolling the pierced steel on a tool of a different diameter.
The manufacturing process of welded tubing begins with rolling steel coils into strips of the required gauge. Cutting follows, which the manufacturer cuts the strips into widths that correspond to your order’s size specifications.
Rollers than work on the cut strip to create tubes, which are welded along the length to seal them. The finishing is by heat treatment after which your steel tubing manufacturer can smoothen the tubing to your liking.
Comparing the two options
When comparing seamless and welded tubing, it is crucial that you specify the material, thickness, diameter, and length of the tubing. Well, that is pretty much what your steel products supplier will also require you to specify when buying steel tubing.
But, it is also from that that you will know whether to order seamless or welded tubing. Using these specifications, manufacturers agree that seamless steel tubing has a higher American Society of Mechanical Engineers (ASME) working pressure than welded tubing.
Ideally, that is because the seamless tubing does not have the welded seams in welded tubing that predisposes the tubing to snap under high pressures.
Manufacturing welded tubing has not reached super-perfect standards. So, there will be visible seams and finishing imperfections, which, however minor, might be a critical concern to some end users.
Seamless tubing manufacturing has also been around for decades that manufacturers have learned and follow best practices for high-quality products. It is from that premise that seamless tubing offers superior rust and corrosion resistance against the transferred chemicals. That is unlike in welded tubing that chances of rusting and corroding along the welded parts are high.
The structural perfections in seamless tubing make it a preferred tubing option for most applications than is welded tubing. Welded tubing is, however, cheaper than seamless tubing, which makes is a better alternative for projects that are not pressure- and corrosion-sensitive.