Pipe stands
Pipe stands
(OP)
I hope this is the right forum. If not, please direct me to the right one. Thanks.
I want to make 4 vertical pipe stands for supporting large electrical motors weighing up to 20 tons. This is only a static load just supporting the motor on the factory floor so that the motor repairs can be done from underneath.
The pipes will be 10 mm thick seamless pipes of 150 mm OD x 130 mm ID x 2000 mm high. They will have welded top and bottom square bases of 300 mm x 300 mm x 25 mm thick for stability. By my calculation, the axial pressure on the pipe wall thickness comes to about 114 kg/sq cm for each leg for a weight of 20 tons. Is this correct?
Is this load within the safe limits of steel yield stress and the hoop stress?
I want to make 4 vertical pipe stands for supporting large electrical motors weighing up to 20 tons. This is only a static load just supporting the motor on the factory floor so that the motor repairs can be done from underneath.
The pipes will be 10 mm thick seamless pipes of 150 mm OD x 130 mm ID x 2000 mm high. They will have welded top and bottom square bases of 300 mm x 300 mm x 25 mm thick for stability. By my calculation, the axial pressure on the pipe wall thickness comes to about 114 kg/sq cm for each leg for a weight of 20 tons. Is this correct?
Is this load within the safe limits of steel yield stress and the hoop stress?
Muthu
www.edison.co.in





RE: Pipe stands
RE: Pipe stands
You also have to check the columns for buckling, even with a pebble under a corner of your base and the motor mounted eccentrically.
You might want to tie the stands to each other, for stability and so they can be moved as a group.
Maybe put spring loaded casters on so they can be moved manually when unloaded,
include lifting eyes so the loaded stand and motor assemblage can be moved with an overhead crane, and bottom connecting beams so it can be handled with a forklift.
Speaking of which, you also should include some sturdy diagonal bracing so the whole mess, stands and big motor, doesn't come crashing down on the floor, the first time the stand gets hit by a forklift or a truck. That _will_ happen.
Mike Halloran
Pembroke Pines, FL, USA
RE: Pipe stands
When you say "pipe stands" what do you mean? Literally just straight pipe?
Unless there is a wholly vertical load and no moment loads or risk of toppling over / swaying, it might be OK, but it's the buckling issue which you need to look at and the other loads.
Draw / sketch it.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pipe stands
The floor is solid reinforced concrete industrial type which is pretty much level. Yield stress of steel is stated around 2500 kg/cm2. Does this apply to seamless pipes also?
Yes, pipes are straight up vertical and the load on all 4 pipes is pretty much even.
Cross bracing is a good idea. I could weld some gusset plates to the pipes outer surface and use diagonal angle braces.
I calculate individual pipe stand weight at around 75 kgs. Spring castors is a good idea to move them around.
I am lost on hoop stress calcs.
Muthu
www.edison.co.in
RE: Pipe stands
RE: Pipe stands
Draw your structure and then get a structural engineer to analyse it. If it goes wrong you will kill the people under the motor. Do you want that? This is not a subject for an Internet forum to decide whether or not it is fit for purpose with suitable factors of safety.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pipe stands
Muthu
www.edison.co.in
RE: Pipe stands
I did respond and thank the posters. Thanks for your advice anyways.
Muthu
www.edison.co.in
RE: Pipe stands
Muthu, seriously, you need to work closely with or delegate the job to an actual structural engineer; this is serious stuff, and clearly a little outside your skillset.
Please don't get offended; get help.
Mike Halloran
Pembroke Pines, FL, USA
RE: Pipe stands
I did the calc for my design and got about 13 tons for each stand.
I have had 32 years doing this with zero accidents. I will try to maintain that streak.
Muthu
www.edison.co.in
RE: Pipe stands
Find what you like to do, earn a living at it, and then make your lifestyle fit your income. — Chuck Yeager
RE: Pipe stands
Now all of a sudden you've been designing structural supports for 30+ years? - "I did the calc for my design " - what sort of calculation?
The picture you post is of a proper structural support with bracing and connector plates and (hopefully) a structural design showing that it meets the required factors of safety from the loads it is carrying. It might even have had a load test.
so what is it? You actually really know what you're doing with structural supports or not?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pipe stands
Find what you like to do, earn a living at it, and then make your lifestyle fit your income. — Chuck Yeager