Q: during, a class calculation in your PCC software I am getting some errors in the weldolets section. It seems that some dimensions (tn) are missing and the program cannot make the simple-pressure rating calculations.

However, when I tick the option “use without specific ratings in ASME 31.8”, the calculation runs without problem (in this case I assume that the program calculates all the individual parameters). Please note that this problem occurs only in calculation with ASME 31.8 (it is ok with EN1594) for pipe sizes 26”-30” with the specific option “unticked”.

There is sometimes confusion about the joint efficiency when you compare the ASME B31.1 and the ASME B31.3. The joint efficiency for the ASME B31.1 (2020) are included in the allowable stress values of Table A-1 (US Customary units). Be careful, because some tables are also available is SI or metric units.

This article is related to the ASME B16.9 fittings specified in an ASME B31.3 pipe class.

The PT rating of flanges depends for some material groups on a reference thickness vR. The definition for the vR might be unclear from the EN 1092-1 standard.

Red-Bag receives many questions about the PCC EN13480 Tee calculation versus the later issued EN10253 dimensions standard calculation in for example Annex A.

"The values for the flanges (service limits) have been entered by using the standard import in the PCC software. However with the calculations I still get an overrun or error. The P and Pmax should be equal at the different temperatures. I get this mistake for all size. Is this due to rounding or what am I doing wrong?"

The PCC software has for the ASME B31.X two modes of calculation:

  1. Fitting with a specific rating (default)
  2. Fitting without a specific rating

In the first mode (fitting with a specific rating) the PCC software makes only a calculation of the corresponding pipe with the same schedule as per the ASME code.

This has to do with the 'N' at the end ofr P355N. The standard EN10028-3 says:

The registration is available for Red-Bag customers only.

There are many questions related the calculation of the EN10253 A/B fittings. This article handles a few of these questions