Pipe supports, welded directly to pressured piping 1

[link88]

Hi,

I looking for help on dealing with my pipe welded to supports problem. I have pipe welded directly to the supports, the pipe sizes very from 6-36" and all should be sch 80. I'm trying to help put together an inspection plan for the welded pipe and I was wondering if anyone had any ideas on the technology that should be used, frequency, etc...

The welded pipe all occurs on a deliver header and was build by the plant. I currently do not have their construction records, nor do I know what specification the piping was built to.

I can tell you that the header is operated to less than 50% SMYS and the typical pressure it sees is 1200 psi.

Regards,

Ryan, EIT

 

[link88]

Another picture 2

 

[link88]

Third picture

 

[Unotec]

Was this piping inspected, x-rayed, etc... as new to register it as pressure piping BEFORE the supports were welded?

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[BigInch]

What code is it?

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[pennpiper]

Based on my experience I see nothing wrong with any of these situations.
The first appears to be a "Shoe" welded to the pipe. This is very common.

The second appears to be a "Guide" to control the positioning of the pipe. Also very common.

The third appears to be a rigid "Base Support" welded directly to an elbow. Again, a very common situation.

These are all referred to as "Secondary Pipe Supports. (Primary pipe supports are the ones designed, engineered and installed by the Structural Department.) Secondary pipe supports are designed and engineered by the piping department and installed as a part of the piping installation sub-contract. If you are going to look for any documentation for these secondary pipe supports you need to look in the piping files.

Do you or others there have a concern about this sort of thing and if so what is it?

 

[BigInch]

Direct welding of supports to pipe is not permitted under some codes.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[pennpiper]

link88,
I suggest that you go here:

http://www.pipingdesigners.com/Training.htm

In "Section III" there are two articles about pipe supports. I think you might find them both informative and interesting.

 

[link88]

At of yet I don't know what code it was built to. I work for the pipeline operator, we own the piping however the plant built/contracted out the building of the piping.

As for the inspection, I don't know. It should have :s

What we are worried about is cracking. Not so much of the weld but the pipe weld. BigInch is right. Canadian code does not let you weld to pressure piping, which half of our pipeline is designed to.

If this is a common practice how do you inspect it? UT? X-ray?

 

[Unotec]

If this is built to pressure piping code as per North America, check out B31.3

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[link88]

Thank you for the link, pennpiper!

 

[link88]

It could be B31.3 but I also heard that it could be B31.1

I'm not very happy with the record keeping.
Have there ever been any failures because of this type of situgation.

Sorry, about all the questions. My background is pigging (MFL) but I have been put in charge of other projects now.

 

[BigInch]

Could be? Ya, that's bad record keeping.
Not a pipeline code then.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[ndeguy]

On the larger diameter headers a UT tech could go inside and straight beam test for fusion (helps if its a full penetration weld) and lamellar tearing of the parent material. MPI weld after paint removal for toe-cracking.

Nigel Armstrong
Lloyds Register
Independent Verification Body Surveyor

 

[JohnBreen]

As Pennpiper said the constructs in the photos are all common ways of attaching "welded appurtenances" to pipe. Note that most of the the welds are NOT continuous - they are intermittent and this allows for local pipe expansion/contraction. When piping is hot, typical welded appurtenances will usually be "heat sinks" and they will lag behind in heat-up and cool-down and thereby cause some local stresses. This is ameliorated by using intermittent welding.

Welded appurtenances are part of the piping engineer's responsibility. You will note that none of your photos shows the pipe supports welded directly to the structural steel members. Those members are the responsibility of the structural engineer and it is the responsibility of the piping engineer to communicate the piping loadings (transferred through the welded appurtenances) to the structural steel for the structural engineer's evaluation of the effect of the loadings on "his" structural steel.

Have a look at the book "Piping Guide", Syentek, David R. Sherwood and Dennis J. Whistance, ISBN 0-914-08219-1, Figures 2.72A and 2.72B for some examples of what you photographed.

Regards, John