Hi,

We have a water transmission system which is being designed as per ASME B 31.4. The line size is mostly above 30" and design pressure is around 6 bar with design temperature as 45 deg and installation temp as 15 deg. Most of the piping is buried except for valve pits and pump houses.

Upon analysis in some of the systems, in operating cases, Caesar is considering allowable stress as zero. It nevertheless calculates code stress at all nodes but as is takes allowable stress as zero, the stress ratio is shown as zero as well.

For the non-buried portion, the Fac value is 0 and for the buried portion, the Fac value is 0.001.

This is a problem only with OPE case. All other cases are showing correct allowable values.

It will be good to have some clarity on this subject.

Many Thanks.