Help Plumbness and Radius Tolerances 1

[JAG713]

Studying for API653 in March been studying for a few months I was able to get study guide for it and running across a problem with Plumbness and Tolerances see example problem below.


A reconstructed tank with a diameter of 100 feet and a height of 40 feet is check for plumbness a bob is dropped from the top outside edge of the tank shell to the bottom outside edge of the tank shell reveals that the tank will not meet the out of plumbness in API 653. What measured was obtained?

A. Greater than 0.4''
B. Greater than 4.2''
C. Greater than 4.8''---answer
D. Greater than 1.2

I know how to use the chart in 10.2 but after that i don't know how to get that 4.8'' also can you show me an example using the same problem with the MAXIMUM out of plumbness ACCEPTABLE.


THANK YOU!!!

 

[IFRs]

The plumbness criteria is not in table 10.2, rather it is in the text of 10.5.2. The tank is 40 feet tall which is 40 x 12 = 480 inches tall. The criteria is 1/100 of the height. 480" / 100 = 4.8" which is the correct answer.

 

[JAG713]

Thank you for your help IFR.