horizontal pressure vessel installation 3

[maatoug]

Hope you are doing well
About horizontal pressure vessel installed 13m on a rack, upon installation and in order to achieve levelness the sliding plate was removed.
Is removing the sliding plate acceptable and can the vessel slide freely without it on the rack?

 

[LittleInch]

It doesn't sounds like a good idea, but that snippet doesn't show sufficient detail.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[maatoug]

littleInch i hope this is more clear

 

[saplanti]

I cannot see any floor bracing on the structure internally at the support level of the vessel. This will be a big problem with or without the slide plate on the structural members since the vessel is expanding and contracting (therefore the base will move with vessel thermal load). The supporting structural members on both side can make the move, and this have to be prevented by bracing. Otherwise the structural members may fail for the unconsidered lataral and torsional loading. The bracing has to stop the structural movement where the vessel supported on both sides. If you design the bracing by using slide plates loads will be reduced. Without the slide plates you may end up considering 0.5 to 0.8 of friction factor instead of 0.2 with proper slide plate.

 

[LittleInch]

Not really.

What is the vessel now sitting on?

As per saplanti - depending on what you used for the friction factor, you could now have a lot more force on the support.

But this vessel looks like it had sliding plates both ends?

Where is the fixed point?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MJCronin]

Why can't the other vessel support (non-sliding end) be shimmed upward and the original sliding plate be retained ??

This would accomplish the same thing .... and there seems to be little piping that would need adjustment

Unless.........unless..........

Perhaps the tank is already installed and your construction group either forgot or lost the sliding plate ... and you are now trying to gain "internet permission" from the west.

Is that true ?.... Is the tank already installed ?

BTW, saplanti is correct and gives good advice ....

MJCronin
Sr. Process Engineer

 

[1503-44]

Usually only one saddle has a slide plate.

REMOVING A SLIDE PLATE IS NOT THE ANSWER TO YOUR PROBLEM.
If a slide plate is to be removed, you must obtain prior approval from BOTH the structural and vessel engineers. They are NOT likely to agree due to minor axis loading concerns and potential axial overstress, respectively. Major modifications to the structure and/or saddle will probably required to remove your slide plate.
REMOVING A SLIDE PLATE IS NOT THE ANSWER TO YOUR PROBLEM.


“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

 

[Trestala]

What is the sliding plate material that was supposed to be installed and configuration? Either the structure or saddle should have been adjusted in height so that it will be levelled.

 

[saplanti]

You can find with following

https://www.google.com/search?q=str...j0j7&hl=en-GB&sourceid=chrome-mobile&ie=UTF-8

It is your/Your company/structural engineer’s decision to select/not select the slide plate application. They probably will want to use it after seeing lateral forces and torsion on the structural members. You are the decision maker, not us.

 

[saplanti]

And, please do not forget to ask permissible bearing pressure on them otherwise your application may not be correct.

Additonally, you need to take the expansion/contraction load with a floor bracing between load application locations due to the friction load and reaction to stop the member moving.probably you are on this path, but I just wanted to remind you again,

 

[Trestala]

@saplanti, better to let the OP confirm what kind of sliding plate was used. It could have just been a carbon steel plate and they've already designed the structure with 0.45 friction factor. They might just let the equipment slide directly on the structure which is a pedestal and not a primary structure.

It seems unlikely they've used teflon or bronze bearing if they've considered to remove it.

 

[saplanti]

I am not their structural engineer to make such a decision. The selection of the slide plate is directly related to the design of bracing system or supporting structure. I hope they can understan this.