Threadolet on the side of an elbow?

[timsch]

I have a customer that wants us to design a bypass chamber with an odd drain configuration. We have a pipe with a short radius elbow butt welded to the bottom of the pipe and they want a hole bored into the side of the elbow to attach a threadolet, which will then have an extended body gate valve attached for a drain. Our bypass chamber designs typically are per B31.3. Where in the ASME codes would a modification such as this be addressed?

Material - A-105 CS
Design pressure - 95 psi
Design temp - 725F
Flanges - 300#
hydro test - 1125 psi

 

[XL83NL]

Use a threaded elbolet as a first, as this may imply a way to compensate for the opening created (if the elbolet is to MSS SP-97).
Others may comment on this (as Im not sure); as you've altered a standard fitting, its not standard anymore, so you might have to qualify it to 304.7.2.
The elbolet at least gives some presumption of fulfilling Code requirements wrt 304.3.

 

[pennpiper]

timsch,
When you do your calculations for a Branch attachment you should use the Maximum Operating Temperature not the Design Temperature.

Just my opinion

prognosis: Lead or Lag

 

[LittleInch]

If it's a SR elbow, how about a tee with a reducer prompty welded onto one branch of the T?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[timsch]

Thanks for the replies. We have convinced the customer to change the design request, so no need for an answer to this question anymore.