Tubes and Pipes

[Tony]

Do steel tubes have a "seam" like pipes? If not, is there a real difference besides the sizes?

[dpb]

Depends on whether its seamless or not... :)

There are both types for various service (primarily it is very high pressure applications that justify the higher cost of seamless).

/geezer-story-alert Years ago (as in when first opening up the North Sea oilfields, J Ray McDermott a large supplier of offshore equipment purchased the entire Babcock & Wilcox Company simply to get the patented proprietary technology and fabrication facilities of the Seamless Tubing Division. B&W and developed the particular process specifically for nuclear fuel cladding tubing in support of their position as the Navy nuclear fuel vendor as well as for their commercial nuclear fuel. McDermott wanted it for the new deep offshore and demanding applications of the North Sea. end-geezer-story/

--

[willshak]

on 12/12/2009 10:12 AM (ET) Tony wrote the following:

It depends upon the manufacturer. Look for 'seamless' steel tubes and pipes, if that's what you want.

[Joe]

There are seamed, seamless, and Bundy tubing which is common in automotive brake lines. Bundy uses a double wrapped construction which is then oven treated to fuse the braze coating on the base tubing. Good stuff for high pressures. Comment on black iron pipe: any one who has had to thread BI for an air compressor or NG project lately will note that the product from China is not perfectly round. Our overseas supplier has yet to master the finesse that American suppliers apply to the BI seams. I suspect many pros are using special cutters to chamfer outer edges so that pipe dies can start a smooth, and continue straight. These days I always dig out the angle grinder and reshape the cut pipe before attempting to thread it. Saves time in the end.

Joe

[Tony]

OK, thanks everyone. I knew tubes and pipes are different and people in the business like to laugh at people that call a tube a pipe (like we poke fun at someone with a hot water heater). No major importance to me, I had just bought some 6" pipe for a project and when I noticed the seam I thought I'd ask.