From the community here, I wish to learn how many of us freeze not only anchor bays, but all support, guide locations in OSBL pipe rack in prelim engineering only for large hot pipings and adhere to the exact positions in detail analysis afterwords.


regards,

sam

Hi Sam,
If I have understood correctly you are refering only for OSBL Piping (hotter ones)on Piperack.
To me OSBl piping running on rack or sleppers are most simplfied ones. As support locations are fixed in sense thhat they will almost in all cases beams. So you can just play with them by putting guides on every after 2 beams on straight runs. While changing direction you have to be careful for lift offs and guides positions becomes critical too.

So once you fix anchor bays, nothing much really left out to worry about.
Yes in case of biggerdia/higher thickness line be on alert especially if anchors (line stops) are placed at larger distance. It could create higher loads on achor points.

There you may have to adopt sectioning of limit stops only for sesimic loads.

Hope this clarifies. Otherwise let me know your specfic Qs.
Cheers!

You might have misunderstood the query; my question was like marking anchor bays in civil structure, whether people mark guide bays too in prelim study & maintain guides at those locations only in detail study.

regards,

sam

Load distribution planning is an important co-ordinated work process between the pipe flex analyst and the C/S people. Its done on a hit or miss basis by most people and when missed drives the cost of the project up.

For OSBL this should not be a problem since there are usually far fewer branches on true OSBL racks that could be affected by one's decisions. Just treat it as FINAL and lock it in like you were doing "issue for constuction" work. Send and email to projects stating some changes may come up later due to preliminary data but hopefully any changes will be minor.

On the other hand for one project, the high and mighty project group got bamboozled by the constructor , against protests and soon to come true warnings from engineering, into locating stops/guides on the ISBL racks during the planning stages. Needless to say the constructor had a good time with change notices or whatever those field guys were calling them at that time.

Good luck and don't worry, the projects folks are smarter than us, so just do as your told. Their opinion is already (always) set in stone.

Thanks. You are right. For us, support/guide positions are as settled between C/S & piping layout - if the same remain frozen, that's just an input for detail stress run.

regards,

sam

Hi Sam,
You should do a preliminary analysis for anchor locations through whatever initial data available and add some contigency factor. And arrive at anchor location.
Even in preliminary plot plan you may put a note covering yourself. And durind detailed stress nalysis you can confirm that.

To my understanding Piperacks are the first thing to constructed at onshore plant. So you should address as early as possible otherwise project ppl will be behind you.

And for similar type of plant anchor bays remain same because of process parameters remains same. So it will give an guidance during prelimary study. Offourse volume handling may differ and accordinly dia`s and thk.

In my opinion, during preliminary study you should not fix the anchor bay location, whatever pressure from project might be there.

It should be done one feed verification P&id`s and line list land on your table.

Hope this helps.
Regards