Pipeline Load on Pig Launcher/Receiver's Mating Flange 1

[SmallInfo]

Hi Experts'

I recently got loads of pipeline mating flange from Ceasor II. I am writing to seek your assistance in calculating the maximum load that the mating flanges of these PIG LAUNCHER/RECEIVER can bear.

Do you use any specific software or Excel spreadsheets to perform these calculations? If so, I would be grateful if you could share them.

Thanks in advance

 

[LittleInch]

You haven't made the pig trap an anchor or line stop have you?

The flange should only see pressure loads.

Need a lot more information here.

I thought Caesar told you if the flange was overloaded?

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

 

[1503-44]

Slot the bolt holes in the skid.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[SmallInfo]

LittleInch,

You haven't made the pig trap an anchor or line stop have you?
Pipeline is anchored in Caesar ii and it has provided force and moments.

The flange should only see pressure loads.
How do we calculate load on flange?

Need a lot more information here.
Whatelse? please specify

I thought Caesar told you if the flange was overloaded?
I just anchored pipeline at point where pig launcher meets

 

[LittleInch]

Let the pig trap move/ slide.

Then all your problems go away.

So a drawing, size, pressure, temperature, where the supports and line stops or anchors are, that sort of thing.

Anchoring a pipeline is a poor way to deal with pipeline expansion. Creates more problems than you solve.

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

 

[1503-44]

Pressure load on a flange is pressure x area of pipe.
The bolts hold it together.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

"I just anchored pipeline at point where pig launcher meets..?"

That's your problem.

It's not uncommon for people to try and analyse the pipeline separate from the piping system but it never works.

Pipelines can exert a HUGE force if there is any level of thermal change, in the region of 500 - 1000 tonnes force if you've got a 24" or bigger.

Anchoring makes no sense when all you need to do is allow the pig trap and piping move max 25mm.

If you model the pipeline out to 250m and the piping back at least 100m before a line stop of anchor your problem will go away and actually be realistic.
Anchor or have a "free end" and it is unrealistic and you get silly numbers.

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

 

[Snickster]

As stated scraper traps should be put on sliding supports so that it moves with the thermal expansion of the pipeline relieving the thermal loads.

In any case flanges can be analyzed using Caesar II which has an analysis in accordance with the Equivalent Pressure Method. This basically takes the bending moment and axial force at the location of the flanges, adds to the intrnal pressure load, and calculates an overall equivalent pressure that determines if the flange will leak. Here is a link to more information on the Equivalent Pressure Method and you can do a search to find even more.

https://whatispiping.com/flange-leakage-checking-by-pressure-equivalent-method/

Attached is a spreadsheet calculation.

If the flanges fail under the Equivalent Pressure Method then a more detailed calculation check is performed per ASME Section VIII, Div. 1, Appendix 2 since the Equivalent Pressure Method gives very approximate results which in some cases are over conservative.

 

[SmallInfo]

LittleInch,
Thank you so much for this useful much needed information.
Snickster.
Thank you so much for sharing spreadsheet, it helped alot.
1503-44
I really appreciate your effports and time.
Thanks again