Seamless VS welded pipe

[farzam]

Dear All,

for our pipeline project the client insist using seamless instead of welded(12" API-5LX60 100barg=design pressure)is there any requirements or criteria for using seamless pipe regarding pressure or size?

Thanks in Advance

 

[pennpiper]

Once you point out to the Client that seamless pipe is more costly and that the ERW pipe is adequate for the service then the "Code" in this case is what the Client says!

 

[metengr]

Unless the code of construction dictates specific requirements, the Owner/Engineer specification requirements prevail.

 

[RossABQ]

If the service conditions would call for a routine inspection/NDE regimen on the seam-weld, I could see a valid maintenance cost concern. There has also been bad experience with Chinese seam-weld, this could be a way to avoid it without saying so.

 

[unclesyd]

There is nothing wrong with welded pipe if it manufactured correctly with some quality control. The old add "You get what you pay for" is very true when it comes to piping.

Making sure you have the right specification for your service requirements and take measures to insure you are getting what you asked for in the piping.

Even though this post was for SS the scenario repeats for CS. The manufacturer can supply you defective pipe if you are lax in your specification. Here is my experience with defective seam welded pipe.
The link in one of my post doesn't work so use the one below.

http://www.eng-tips.com/viewthread.cfm?qid=70822&page=142

If you would like to read what you can get into contractural wise read this paper. I know of an ongoing litigation concerning ERW pipe where this opinion is being cited. When I say ongoing I mean crawling.

http://www.uscfc.uscourts.gov/sites/default/files/Mortenson.pdf

 

[EdStainless]

This may a case of a lazy user. After all the inspection and assurance of code compliance are the responsibility of the purchaser. The may feel that it is easier to buy seamless and not inspect than to buy welded and inspect.
At least they will feel that way until they get some seamless with through wall defects in it.

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Plymouth Tube

 

[unclesyd]

Through the wall defects on seamless tubing must be a new problem or we were extremely lucky.
This is not saying they are not out there but in my 42 years associated with fabrication shop I have never seen a new seamless tube with a through wall defect and we bought tubes from Plymouth, Rath, Trent, Greenville and a few others. Other than shipping problems the only detrimental defect I recall was on some 1 1/8" 10 gauge tubes where half were about 0.015" undersize. Our in house shop built or rebuilt on the average of 35 tube bundles a year and several years many more. We also built bundles for our sister plants on as time permits basis or an emergency. Until around 1970 the tubes were all welded and at that time based on the reasons put forth in my previous post we switched to seamless for both 304L and 316 SS. Due to variable corrosion rates on our few 316 SS bundles, 31 of them either installed or in process of rebuilding, we ran an as built eddy current survey as a baseline for future eddy current inspections. Until the onset of MIC I never saw a through the wall defect in seamless tubes caused by corrosion other than SCC.
I don't see any manufacturing defect being the responsibility of the user, especially when they pay for inspection above the norm or more than code requirements. In my referenced post one will note that we paid for and expected a 100% inspection by all means necessary to insure the integrity of the product. You might say that it was the wrong specification but unless you know the situation that existed with user as it may have been the only out. In our case I know that at different periods time constraints necessitated the use of a product not the best for the service but by specifying, paying for, and being assured by the manufacturer that the product will be an acceptable substitute for our process requirements. Generally anyone will use this material without further physical inspection based on the integrity of the manufacturer. We always looked at the metallurgy of any SS or alloy pipe or tubing.

Inspection alone can not insure quality it can only check quality as there has to be concerted effort on the manufacturer to produce a quality product prior to inspection.
It must be that quantity has overwhelmed quality.