B31.3 Branch Connections

[dcb2]

All,

I have a situation where I need to stub into a welded 90 degree elbow with a reinforced connection. The seam weld of the elbow will be the centerline of the branch connection. The stub in will remove some weld and the reinforcement will cover the elbow weld seam. The elbow was purchased as 100% xray. The stub in and reinforcement will be to B31.3 requirements.

Does B31.3 prohibit the location of the branch connection along a weld seam? I have read throught he code and can not find any reference to this situation.

Thnaks for any help.

dcb2

 

[unclesyd]

No it doesn't prohibit this. If fact it's the most common location for branch connections on elbows.

The fact that there was a 100% RT makes E=1. The weld doesn't exist as far as calculations are concerned.

It is not a good practice to straddle a weld seam, but i some time has to be done.

You might want to check on Elbolets.

http://www.bonneyforge.com/

 

[DSB123]

I agree with unclesyd Elbolets would be a better option. Also it must be remembered that the flexibility of the bend will be modified (i.e. reduced) and the SIF's local to the branch so the thermal stress levels will need to be checked.