Seamless Pipe

As everything in engineering, there's not a preferred object to be used everywhere.

Seamless pipes are used where you need, by high pressure, high stress, high reliability. They are more expensive, and are manufactured in less scale that regular welded pipes.

If you don't have how to reduce the stress in the material, go for a better material in seamless tubes. If your requirements are not so high, use the cheaper material.

I'm pretty sure that in refineries there's a lot of welded tubes around.

Regarding your question about the pending choice of seamless pipe vs. welded:
In my working past we grouped both ERW (eletric resistance welded) and SAW (submurged arc welded) pipe as "welded" pipe and apart from seamless pipe. The key point is where would we use seamless pipe and where would we use welded pipe? Most of the use restrictions was dictated by the client.

Welded pipe was used where there was a predominance for low pressure and low tempurature, such as in tank farms, water treatment, etc. Seamless pipe was called for and a mandatory requirement inside the battery limits of hydrocarbon processing units. The main reason cited was better resistance to rupture during a potential fire. The second reason was the high potential for reuse of pipe inside a process unit for another purpose resulting from a revamp. To explain this point, say a water line was installed using welded pipe during the original construction. Now, ten years later during a revamp the type of pipe was not checked and the old water line pipe is reused in a hydrocarbon service. The hydrocarbon line then becomes subject to a higher pressure and tempurature. It then bursts because the welded pipe was not rated for the new service

Think about it.
Jop

Hi,

this is srinivas Plese send welded and seamles pipe presure temperature ratings.