Measures to Allow Pipeline Expansion 1

[jonjose123]

Hi All,

Good Day!

We have an aboveground pipeline 6" with design pressure of 140 barg and design temperature of 93 deg c.

In order to make allowance for thermal expansion, expansion loops are proposed.

However, in the handbook of Pipeline Engineering by Henry, there mentions about certain mechanical joints to be used.

has anyone come across with such situation..? .

is there any way in which we can avoid expansion loops in the above ground pipelines.

Regards,
B

 

[MFJewell]

Expansion bellows may be an option. We had many of them installed on steam lines at the nuke plant I used to work at.

 

[MJCronin]

Jose...

Expansion bellows usage at 140 barg is unlikely. Mr. Jewell, you probably do not have any steam piping systems operating at 140 barg at your nuclear plant

93C is a modest temperature. I suggest that you review the "Piping Handbook" chapter on expansion and flexibility. There is much information on the internet on this subject. Reconsider piping expansion loops, which is usually the cheapest solution.

Consider performing a detailed piping stress analysis (CEASAR-II)to confirm your design.

Why are you against piping expansion loops ?.... Explain

http://www.thermacor.com/wp-content/themes/thrma/flat-theme/pdf/technical-data/15.103-4_001.pdf

MJCronin
Sr. Process Engineer

 

[pennpiper]

jonjose123,
After more than 45 years in the Piping Engineering and Design profession my opinion is this:
(a) Avoid Expansion Joints when ever possible
(b) Use only Expansion Loops when ever you have long straight runs of piping
(c) Use shape ("L" or "Z") configuration for flexibility in non-rack piping

Remember:
1, All "Hot" piping requires properly designed and properly placed Anchors and Guides
2, All "Hot" piping requires the Attention, Analysis and Approval ( Triple A) of a qualified Pipe Stress Engineer

Sometimes its possible to do all the right things and still get bad results

 

[LittleInch]

Try burying them.

Do you really mean pipeline or piping?

Mechanical joints at 140 barg are rare and expensive.

You can try multiple clamps.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MFJewell]

Mr. Jewell, you probably do not have any steam piping systems operating at 140 barg at your nuclear plant

Correct, it was about 300 psi (20ish bar). Not sure what they max out at, that is why I said the MAY be an option.

 

[jonjose123]

Thank you all.

As Littleinch asked.. yes it is pipeline ASME B31.4 code.
Length of the pipeline is 5 km and we have 5 lines in parallel of same size 6".
And as per route, we have road crossing at every 500 m.

We want to mitigate the expansion loop or replace with other option.

Regards,
B

 

[LittleInch]

So why can't you bury them?

You can run them in aZ shape wherry the long bit of the Z is at slight angle to the overall straight line route. This minimises no of fittings.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MJCronin]

As always, pennpiper gives the best advice ......

MJCronin
Sr. Process Engineer

 

[pennpiper]

jonjose123,
I have some followup comments and questions:
(1) You wrote: "We have an above ground pipeline 6" with design pressure of 140 barg and design temperature of 93 deg c."
You should never base thermal expansion on "Design Temperature". You should always use actual Operating Temperature. You did not say if the piping would be insulated or not. Depending on the geographic location of your project and if not insulated you may need to base your design on Solar adsorption.
Where is this project?
Will the pipe be insulated?

(2) You wrote: In order to make allowance for thermal expansion, expansion loops are proposed. The first choice is to look at the route of the piping and consider the path of travel including the vertical contour of the land. Then develop a piping configuration that fits that route. You may find that you have less problems with expansion just due to the configuration.
What is the configuration of the route?

You wrote: "However, in the handbook of Pipeline Engineering by Henry, there mentions about certain mechanical joints to be used." You state there 5-6" pipe lines. You did not tell us if there will be "Pigging" of these lines. If there will in fact Pigging of these lines that is another reason to use only Loops and not some form of mechanical joint.

(3) You wrote: Has anyone come across with such situation..? . Yes this is not new to the world of piping. There have been many projects over many, many years.

(4) You wrote: Is there any way in which we can avoid expansion loops in the above ground pipelines. Probably not. One issue you have also failed to share is the manner of support and the elevation of support above ground for these 5 lines. You said you would not be burying the piping then so how will you support them and how high above the ground?

Additional Questions:
(5) What is the commodities in these 5 lines?
(6) Where in the world is this project?
(7) Is this project located in a remote location or in or near a populated community?
(8) What is the function, purpose of these lines?

Sometimes its possible to do all the right things and still get bad results