Corrosion allowance and hoop stress cal

Posted by: Pros

Corrosion allowance and hoop stress cal - 08/30/05 05:50 AM

Hi,
The default in caesar II 4.5 for hoop stress cal is ID, but that does not take Corrosion allowance into account when calculating hoop stress.

Can anyone suggest the best selection out of ID, OD, mean and lame equation to better take care of the corroison allowance throughout the life of the pipe.

Pros
Posted by: John C. Luf

Re: Corrosion allowance and hoop stress cal - 08/30/05 06:13 AM

Which code are you doing your work under... Caesar II follows the codified rules of various codes...
Posted by: Pros

Re: Corrosion allowance and hoop stress cal - 08/30/05 06:45 AM

I am using B31.3 code
Posted by: El Gringo

Re: Corrosion allowance and hoop stress cal - 08/30/05 07:11 AM

Simple! Read 31.3 section 304. And don't forget to check the errata (see Dave Deil's post)--formula 3a has been corrected.
Posted by: El Gringo

Re: Corrosion allowance and hoop stress cal - 08/30/05 07:26 AM

A few more comments:

First, sorry Dave; I misspelled your name.

Second, I thought that C2 does consider corrosion allowance to check the wall thickness.

Third, I believe C2 does not check wall thickness for vacuum conditions. You have to hand calc that using the BPV code, Section VIII.
Posted by: Richard Ay

Re: Corrosion allowance and hoop stress cal - 08/30/05 07:54 AM

Corrosion is considered in the "min wall" calculation if defined in the input.

The Stress Report is a different matter. The handling of corrosion depends on the code and the load case, as well as the Configuration Directive All_Stress_Cases_Corroded.

So, with All_Stress_Cases_Corroded set to "unchecked", which is the default:

- B31.3 would corrode the SUS and OCC cases, and the corresponding Hoop entry (even though it won't affect the code stress).

With All_Stress_Cases_Corroded set to "checked:

- B31.3 would corrode all load cases, and the corresponding Hoop entry (even though it won't affect the code stress).

CAESAR II does not address Vacuum conditions.
Posted by: Pros

Re: Corrosion allowance and hoop stress cal - 08/30/05 08:50 AM

Thanks for your answer.
Regards,