Curved Plate (L-shape & U shape) Design under Internal Pressure

**pkmaharia22** · 03-07-2010, 07:37 PM

Hi... I'm new to this web-page. I hope that I'll get answers of problems in designs.

I want to design a curved plate (L-shape, U shape) under internal pressure. I've searched in ASME section VIII but didn't get the answer.

How do I determine the required thickness of a plate at the bend or curved portion?

Can you guide me towards any Code?

Please help me.

Thanks

Pramod

**bajupk** · 03-07-2010, 11:57 PM

Pramod,

why u not apply rules for calculating thickness for curved dished / spherical heads...as they also have curved geometry.

Though not exactly same what u r looking for..but can give u some insight

cheers

**pkmaharia22** · 03-08-2010, 05:10 PM

Bajupak

Thanks for your suggestion.

Actually, I've a straight plate. I need to bend it to make a vessel which is under pressure. While bending a plate, there is slight reduction in the thickness of a plate in the bend portion (@ corner of L-shape).
How much will be the reduction in thickness at the corner of L shape or at the bend portion. Is there any relation which is function of the bend angle, to determine the actual thickness at the bend?

I have tried to use the UG-27 & UG-32, by considering the cylindrical or spherical vessel. In both the cases, I'm getting 0.018mm the required thickness instead of 5 mm which I'm getting by considering a flat head (UG-34).

Can you help me out in this??

Thanks

Pramod

**A.Venugopal** · 03-08-2010, 05:33 PM

Dear Mr Pramod ,

usually thinning will be of the order of 15 % . I do not think there is any ready to use formula for estimating the thinning . Usually inspectors ask for a mock up piece for demonstrating the extent of thinning . Thickness calculation for curved plate and a flat head show huge difference naturally. You may look for some guidance on rectangular tanks in Megassey.

Until more knowledgeable answer is offered by others I hope this may be of use.

Best regards

Venugopal