Hi all,

I have a piping desing as attached. The pipe is 6". Maximum temperature is 180C. There is a displacement of -11mm at node 1100. Can anybody help me and see if the support locations are acceptable?

Thanks,

Your design looks reasonable, without getting a look at the stress report. In general, it's best to support risers at the top and provide enough separation between the bottom of the riser and the nearest support to allow the deflection without generating an overstress at the first support on the lower level. If the stress report says you've done that, and you can withstand the occasional loads appropriate to your site, and you can tolerate the small pocket created at the base of the riser, run with it.

It can be a tricky balancing problem to meet all the above criteria for the first support location. Structural engineers can be SO touchy about adding a steel member in between the bents of their pipe rack.

Is node 980 an anchor..? Is it an equipment or just fixed acnhor support? Because your support locations may result to big torsional load that will cause failure to that point. I suggest reduce the end point reaction and play it with flexibility.

Regards,

Well, everything looks fine but the Anchor (node 980). As bom pointed out, the moments and torsional loads at 980 will be a problem with this arrangement.

If fluid draining is not a problem then I would recommend removing rigid support at 1140, placing a rigid support at the bottom of the riser and guiding the pipe on top - at 1140.

This will 'slightly' compromise with stability, but anchor loading will be under control.

Also, under this arrangement, do adjust the location of 1150 to prevent lift-off at this support due to thermal growth of the riser upwards.
And ofcourse, not to forget, the stress-report and structural-steel availability, as Sir CraigB pointed out.

Regards,
ASA

Thanks everybody for your help.

The anchor is acturally bolted to a valve. The reason I don't want tp add the support of bottom of the riser is because the support at 1150 lift off and it cannot be adjusted since the sturcture is already in field.

I removed the anchor at node 980 and add the valve and piping in. It turns out the stress is quite low.

Great!I suggest you to remove the support from 1140 and add a support between 1100 to 1110 (i think you can find it 3000 to 3300 after 1100) while there is no lift up. It helps you to control any occasional load by choosing any guide or stopper in riser.
cheers