Welding LATROFLANGE on Flat side of ECC.Reducer 1

[pipeneer]

My question is If we (or is it allowed ?!)weld a Latroflange on to the Flat side of an existing 24"x20" ECC.Reducer in a LP Steam Line (DPr.& DTemp.:8.5 barg&290 Deg.C ), will the amount of SIF created(if significant) have a drastic effect on the integrity of the ECC Reducer?.Material for the RED is A234 WPB and the Latroflange A105.
Your replies will be greatly appreciated.

 

[metengr]

pipeneer;
You should carefully review ASME B31.1 for this application. You will most likely need to run a stress analysis of this configuration and to check the area reinforcement in accordance with B31.1 to make sure that there is adequate reinforcement in the reducer because of this penetration.

 

[Berndt]

Yes, it is allowed but only after you've jumped through a couple of hoops first.

I agree that a stress analysis of the system would definitely be in order. However a reducer is a standard fitting according to B16.9 with standard SIFs. As soon as you make changes to the reducer, such as welding another fitting onto it, the standard SIFs no longer apply and need to be recalculated using a FEA program such as FEPipe. These calculated SIFs should then be used in the stress analysis. In the stress analysis it is important to know what piping code you are designing to. If your system passes the stress analyses then you should be home free.