Hi,

Is there any standard method for calculation of stresses in cylindrical pressure vessel being lifted by sling. In "Pressure Vessel Design Manual 3E" by Dennis Moss, there is one page (page number 413) for design of vessel for choker. However I have confusion about the terms Zin, Zout and A. Has any body used these equations?

Many thanks in advance.
M Waheed

Hi,

I would like to add following to my previous post.

The method given in "Pressure Vessel Design manual" is a combination of case 12 and 18 (Table 17) of book by R J Roark, 5th edition. I used this method and calculated stress as 6M/(t*t). It gives me very high stresses (thousands of MPa). However if I use case case 15 of table 30, I get reasonable values of stresses such as ~170MPa.

Is any body out there who have used these equation to calculate stresses in vessel lifted by sling or know any other method?

Thanks and regards

M. Waheed

Hello M Waheed,

I haven't used the method described in Moss.
I studied the equations.

a) The term Zin,Zout are section modulus of the Beam at the innermost and at the outermost fiber respectively.

b) Also the A term seems to me the cross sectional area of the Beam since due to the "T" force the beam will be subjected to shear.

Hope this helps.

Regards
asd23789

Thanks ASD23789 for your response,

I used these terms you describes as well as using 6M/(t*t). This gave me very low stresses such as 1.5MPa. Whatever terms I use the stresses are not what one would expect.

Thanks

Hello M Waheed

can you send me the input data you use for the calculation?
I will try it to calculate at my end?

Regards

ASD23789

Thanks asd23789,


Vessel OD = 1276

Thickness = 10 mm

Weight of the vessel to be lifted = 12300 Kg

Length of the vessel = 7 meters

Regards

M Waheed

Thanks ASD23789,

I also came with the same results. However the stresses are so low that seem unrealistic. I also have doubt about the use of Zin and Zout.

Thanks for your help

M Waheed

dear Mr. ASD23789,

Even i have similar problem, can you send me your email id so that i can contact you if you dont mind.

thanks,
Sameer
sameercnn@rediffmail.com

Dear Sameercnn

My email Id: asd23789@asia.com

Regards

ASD23789