Hi,

I did an ASME B31.3 piping flexibility analysis for a sensitive equipement piping, which led me to specify sch10 piping for 14" carbon steel piping.

With this nominal thickness (6.35mm) I checked the loads on the equipment for allowance.

Then, delivered elbows wall thickness, as measured, range from 8.2mm to 9.6mm.

This seems compliant to ANSI B16.9, fig 1, for which max thickness as calculated to formulaes 1b-2b is 9.56mm.

Since this could increase the loads on the equipment, does this mean I should have made a separate calculation model, for loads check only, with max thickness of delivered piping ? Or are those tolerances taken into account in CAESAR's calculations?

yours truly,

Cyril

CAESAR II determines the "weight" loads on the system based on your input thickness value. There is no adjustement or tolerance.

If your delivered pipe is 9.56mm, and your analysis used a value of 6.35, yes I would copy the model, change the thickness and rerun.

Richard, thank you for your answer.

Do you think I should always use the highest permissible thickness to check the loads on equipment or weight, hanger pre-stress or whatever?

I mean, I always have used nominal thicknesses in my calculations so far...

Does anyone take this thickness upper tolerance into account on every calculations?

I understand "the code" does not specify this maximum thickness thing for flexibility calculations, but it affects a lot the loads on the equipment.

yours truly.

I've only seen this done once, and then it was done because the pipe came in so heavy it bottomed out all the springs.

So yes this is a concern that should be evaluated.