HORIZONTAL LOOP

Dear All,

i have designed 36" pipeline (Pressure 200 psi & Temp 170 F running on sleeper @ every 12 meters , th total length of pipeline is 500 meters. Intalled either ends with anchor, horizontal loop at 250 meters, to accommodate the expansion.

system passed.

i tried without loop, it also passed.

my question is whether loop is required or not

Looking forward experts answer
regards

In addition to meeting Code requirements, it's also necessary that the end reaction forces be within reason. If your straight pipe has end reactions that are within equipment limits (or within sensible structural design limits) then you don't need the loop. If you're not sure what equipment limits are, check with your equipment engineers. If you're in doubt about "structural design limits," talk to your project's structural engineer.

So the brief answer to your question is that nobody on this forum can give you an answer as to whether the loop is required or not. It's unlikely that, even if you posted the end reaction forces (and moments) we could give you that answer either. The answer lies within your project team.

Please check if the anchor loads are manageable. They must be huge, so more than one expansion loop(or one long loop) may be required for that long straight line. This issue has been addressed many time in this forum before.

Regards

Did you check out 'Add F/A' option in the config. file ? Stress may be high but acceptable, but what about Euler buckling ?

A quick check tells me your end forces must be around 5.5 MN or 1.25x10^6 lb. If this is ok, your structural engineers are either magicians, or just mad. Use a loop, don't just accept results because they are not printed in red.

Hi pipehawk,

I remember this once "NO EXPANSION LOOP INSTALED" about 110meters. a piping engineer forgot to put expansion loop. Now my teammates just input it for the reason we were new to this job.
Then passed the calculated data to the structure guys.. They are laughing hysterically (A horizontal load is about 100tons!).

I know that anchor are not that infinitely rigid,.. but what assumption can you make? Should we put expansion loop? or input a stiffness value for the structure? Now doing stiffness input,. maybe they wont laugh anymore BUT you will be praying not to loss your job.

Regards!

pipehawk I do not wish to insult you but you should not be doing meaningful work alone.... obviously you do not understand the limitations of the software and the piping code. Therefore if you make a mistake and dont know it what will the consequences be? Learning this art soley on an internet forum is not the way to go. Coopers, silversmiths, etc all have prolonged apprenticeships and yet all people think they need is a copy of c2!!!????

Luf-Sir,

We can't blame the person only. It is the failure of the environment where he is entrusted with such work without supervision.

In many developing countries having populist democracy in place, we are noticing this disturbing trend of expanding educational infrastructure without developing enough amount of quality teaching staff & compromising the quality of student intake.

So, we may get Coopers, silversmiths with engineering degrees nowadays! I am not demeaning the wisdoms of Coopers or silversmiths by this.

regards,

sam

pipehawk ,

Pl conclude this issue, would be useful for further reference,

Regards,
Rams

Dear All,

Thanking everybody for the quick reply to query.

once again thanks for given me good idea about loop.

Regards