About a support in a refining

Posted by: M.Mohammad

About a support in a refining - 05/29/12 10:33 PM

Dear friends,
I have seen a weight and guide support in a refining that that its weight support has a 10 mm gap. I attached its picture in this topic for giving your idea about this.
My general question is about this gap.
Posted by: edevor

Re: About a support in a refining - 05/30/12 07:21 AM

Dear Mohammad,

Can you please provide some more information. Is the system in operation or this photo has been taken during erection phase? What type of piping system is (from process point of view)? Do you have any draft sketch of the around circuit?

Kind Regards
Posted by: Dave Diehl

Re: About a support in a refining - 05/30/12 09:30 AM

Looks like two CAESAR II restraints to me - a Guide and +Y with your gap of 10 mm. (+Y is up)
Posted by: Yhebostress

Re: About a support in a refining - 05/30/12 04:13 PM

In actual design practice, support designer do this kind of detail design (design trick) for fabrication to satisfy the stress requirement of a particular line. In this particular case, I suspect the large bore line is supported at higher elevation (or connected from nozzle above) which is intended to thermally expand downward but needs to be guided the small size vertical line (for lateral restraint) - the weight of small size line is supported by the large bore line. And because the stress analyst located the vertical guide "too high" from the steel structure (of the platform), the support designer has to provide an extra trunnion and T-Post (with sufficient/large gap enough to allow the expansion of piping downward without clashing on the T-post and avoid overstressing the tee branch and the trunnion weld on pipe) to "bring up" the guide at the requested location. The weight support (of T-Post) has no purpose in this case and just put there so that there is nearest steel available to weld the guide and thus connect the lateral reaction load of piping into platform's steel beam below. In Caesar-II model of the stress analyst, it is just a vertical two-sided guides (X or Z); no +Y with gap.
Posted by: Jop

Re: About a support in a refining - 05/30/12 05:04 PM

M. M. did not provide enough information graphically or by written description for anyone here to make any kind of intelligent comment.
Posted by: Dave Diehl

Re: About a support in a refining - 05/31/12 06:49 AM

If no +Y with gap, then be sure to check for clash be keeping an eye on the reported Y deflection at that point.
Posted by: M.Mohammad

Re: About a support in a refining - 06/04/12 11:31 PM

Dear e devor,

This case is in erection condition and i think it shall operate in high temperature.
Posted by: edevor

Re: About a support in a refining - 06/05/12 05:12 AM

Dear Mohammad,

I believe that the best is to ask the person that perform the stress analysis. Nevertheless this type of supporting is quite "uncertain". The expansion from Caesar and the expansion during operation some times may differ. Client not always operating their plants at the design conditions; some times the are running over the design conditions. So, the designer need to be very careful when such gaps from calculations are translated to piping support details. For instance when the piping is moving vertically and guide support is required by the stress analysis, then a rigid strut is quite safe device for this type application.

In any case I suggest again, that stress analyst shall be contacted prior to any action on a piping system that is in erection/operation.

Best Regards
Posted by: Jop

Re: About a support in a refining - 06/05/12 05:30 AM

If you look at the picture in detail I think you will see that this is a view of an unfinished work in progress.

Item:
The platforming - it looks "New", it looks clean having no indication of spillage or aging.

The large center pipe/equipment/whatever - It stops at the flange below the reducer and does not continue through the banded hole in the platform below. Something is missing.

The area in general - There is loose trash and cable on the platform that indicates "still under construction" status. This is further born out by the presents of erected scaffolding in the background.

What's missing - If this is really in a "Refining" (Refinery) situation then I would expect to see insulated equipment and piping. So far there is no insulation on this equipment/piping. Does this mean that this picture is not of a "Hot" system or does this support the idea that it is an unfinished construction site?
Posted by: Jop

Re: About a support in a refining - 06/05/12 05:31 AM

If you look at the picture in detail I think you will see that this is a view of an unfinished work in progress.

Item:
The platforming - it looks "New", it looks clean having no indication of spillage or aging.

The large center pipe/equipment/whatever - It stops at the flange below the reducer and does not continue through the banded hole in the platform below. Something is missing.

The area in general - There is loose trash and cable on the platform that indicates "still under construction" status. This is further born out by the presents of erected scaffolding in the background.

What's missing - If this is really in a "Refining" (Refinery) situation then I would expect to see insulated equipment and piping. So far there is no insulation on this equipment/piping. Does this mean that this picture is not of a "Hot" system or does this support the idea that it is an unfinished construction site?