I have a 42 inch pipe lined with cement (service:salty water); code:ASME B.31.3. I have to questions. 1)Is it correct to carry out the stress analysis in Caesar. My question is due to SIF's used by CAESAR are based on Table D-300 (B31.3) and its validity has been demostrated for D/t less or equal than 100. I have D/t greater than 100. 2)I read B31.3 chapters related to Piping Lined with non-metals in order to know how to perform the analysis (due to differences in properties between CS pipe and the liner, but I do not find a clear answer. Could anyone help me?

You can perform the analysis with CAESAR II, but:

1) Your D/t over 100 means the SIFs computed by the software (according to the code) may not be applicable. You will need to do further analysis of your fittings, using the forces and moments from your CAESAR II analysis, to determine if they are acceptable.

2) You can specify the cement lining as refractory, in which case CAESAR II will only consider the weight of the lining. CAESAR II will not consider the lining in any strength or stiffness computations.

For the sizes mentioned and Large D/t ratios,a run using the Caesar Beam element model would be ok for an estimation of support loads,displacements etc.

A Supplemental Finite Element study of the supports (your configuration may ask for saddle type of supports)and SIF estimation may also be required. Have a look at paulin research.com . They have some literature on large D/t ratios and application of their utilities for such models.

Regarding the lining , you have to judge on the deflection limits of the lining and its effect on the equivalent stiffness and expansion.

Generally the lining thickness of sea water line(cooling water line) is very small and the effect of cement-mortar will be minor and negligible in a piping stress evaluation. However, it will affect to the support and equipment nozzle loads and the maximum deflection of piping system due to combined weight must be checked not to bring the damage of lining material during operation.
There are two ways to evaluate stress of lined pipe. Equivalent moment of inertia(i.e. equivalent thickness) and equivalent elastic modulus. It seems that equivalent thickness method is more commonly used.
The equivalent thickness is calculated by first calculating the combined stiffness of the cement-lined pipe, and the equivalent moment of inertia; the equivalent thickness can then be obtained in terms of the pipe diameter and the equivalent moment of inertia.
For more detailed equations, please e-mail to me.

For D/t ratio larger than 100 pipe, the SIF and pressure calculation in the ASME B31.3 may not be valid. For code compliance, see para.304.7.2 in the B31.3. The valid SIF may get from a fitting vendor or FEA(FE/Pipe, as mentioned above).
The simplest way is to use thicker pipe only for elbows and branches for main process lines. However, for utility system like cooling water line, it is no big deal….it’s up to your decision.

Dear Sun Wee,

Quote : For more detailed equations, please e-mail to me.

Unquote :+++++++++++++++++++++++++++++++++++++++++++++++

Could you please send data as mentioned to my email Address ; davesnehal20@gmail.com