Motor support inside pressure vessel

[Ehiman1]

Good morning,
I have to calculate thickness and bolts size of a motor support plate welded inside a pressure vessel shell course with ASME code.
The support has circular shape and a hole at the center with the motor bolted on plate by 12 bolts 1” type (like that ones on reverse flange).
In this case we have internal pressure and loads from motor (shears, axial load and moments) for this reason We calculated an equivalent pressure to verify the plate support thickness with UG-34.
But what about bolts? How can we verify that bolts is enough in this case?

 

[saplanti]

I would be more concern on the dynamics side of the problem. The welded flange (weld type might be important) on the shell may end up fractures on the weld as well as on shell wall due to the dynamic variable loads.

In case the motor inside the vessel and the vessel is split into two section by the flange and motor connection, can you still maintain pressure balance on two sides. How about pressure fluctuations.

If you can sketch everything on the paper you can , I believe, figure everything out easily. the bolt connection is probably the easiest if everything is static. You may be able to use Roark's Stress and Strain Handbook for the thickness calculation for the adequate load cases and perhaps their combinations. After the derivation of thickness you may run an FEA for the dynamics to verify your application and fatigue evaluation.

I guess, if you can come out with and adequate sketch, you will get adequate and satisfying answers.

 

[Tmoose]

Does the motor drive an agitator ?

Rotating machines in general require their neighbors' and support structures' design to seriously consider fatigue. At 900 rpm a rotating device causes over 1,000,000 wiggles per day. Things like weld toe detailing often are found to be extremely important, even moreso than "normal" concerns like weld filler tensile strength and weld size.