Flush-type Shell connection

[ll23]

We have a doubt about the design of the Flush Type Shell connection, in our weld sketch indicates an insert plate in which we are going to put our nozzle, following the recommendations of paragraph 5.7.8 of API 650 12th

But the corners of the insert plate in our design show a square cut, we discuss this design our engineering department, based in the paragraph 5.7.1.6 and 5.7.1.7, their answer was that those paragraphs concerns about other types of connections rather than a flush type, in consequence doesn't apply, and the guide was the figure 5.14 depicted above, is this square cut possible?

 

[JStephen]

The image isn't working for me.

 

[ll23]

Sorry
[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1484848309/tips/Untitled_h9hfji.bmp[/url]

I think that square in the bottom of the figure it's the shell plate, but in our design we are putting our flush type assembly in an insert and then we're going to weld it to the shell, after the PWHT.

 

[JStephen]

I think the square corner shown is assuming it is inserted into a full-height shell plate. If inserted into a smaller insert plate, I would assume the top corners of that insert plate were rounded per 5.7.1.7.

 

[IFRs]

Flush cleanouts must be installed in a "shell plate" while flush nozzles are installed in a "shell or insert plate". The definitions of "shell plate" and "insert plate" are in section 3.14 - when an "insert plate" is the full height of a shell ring, it is "shell plate". If you are making a flush shell nozzle, not a flush cleanout, you should be using figure 5.14 where it shows the upper corner square but the text is different than in figure 5.12 and it allows for the assembly to be in a shell insert plate. Since a shell insert plate is not the full height of the shell ring, it will need to have rounded corners per 5.7.1.7.