Required Reinforcement Around Threaded Port - UG-34/37? 1

[rman487]

Hello all,
So I am trying to figure out how the ASME code applies to a flat plate with a single threaded pipe port in the center. The plate is bolted down, so I am using UG-34 as the basis to calculate the "web thickness" of the plate (disregarding the pipe hole in the plate). Then, after I get that thickness, I want to analyze how the code provides guidelines for the threaded boss reinforcement around the port. I've looked at UG-37, but it isn't clear to me if this section of the code applies to threaded ports inside the flat plate. Can anyone provide guidance as to what code is applicable? Thank you.

 

[SnTMan]

See UG-39

Regards,

Mike

 

[rman487]

Mike,
I've reviewed UG-39, but it appears that the code assumes that the threaded section is welded on the pipe. I'm trying to find an analysis method for determining the height and thickness of the boss assuming it is just part of the milling process to make the flat plate?

 

[SnTMan]

rman487, you may have to draw me a picture, but:

Why can't you treat the boss AS a pipe? I don't think the Code assumes the opening is threaded, or not threaded. Just use appropriate OD, ID at the thread root, height of reinforcing element, limits of reinforcement, etc, etc.

Also see UG-36(c)(3), you may be able to exempt the thing.

Regards,

Mike

 

[rman487]

Mike,
Thanks so much for your help, I believe it is exempt as a result from UG-36c3. Thanks!

 

[chicopee]

IF not exempt from UG-36c3, then, I would think that calculating the boss as a reinforcement/compensation of the opening as a viable option.

 

[rman487]

Chicopee,
What section of the code were you referring to that would apply to calculating as a reinforcement for the boss? Is it ug-37?

 

[chicopee]

Unfortunately, I gave my set of ASME codes to the Springfield library several years ago, however, I still retained " Pressure vessels- ASME Code Simplified", 6th edition authored by Robert Chuse and Stephen M. Eber,PE. Reinforcement/ compensation of openings is detailed on PG 90-93, so see the attachment of a sketch that I made based on that information. On pg91, they refer to UG-39, UW-16 and UW-12.
There is an alternative code that you can reference and that is ASME Power Code I. When I took my National Board exam, alas, in the 1970's, I had to study sections PG33,36 and 37 dealing with this topic and I am quiet certain that the methods explained in the Fired and Unfired Pressure Vessel Codes are similar from what I remembered when I compared the two codes.

 

[chicopee]

Here is a link that should help you "Openings in ASME Code Pressure Vessels - PDH Center" at

http://www.pdhcenter.com/courses/m205/m205content.pdf

.This author has multiple sites that may help you.

 

[GenB]

You are allowed to weld buildup to increase the t of a plate for the purpose of adding more threads if the plate is thin (a boss buildup), you cannot use weld buildup for compensation that is why you will use a coupling or other connection. If the opening is exempt and the opening its threaded no other calculations needed. If welded connection you have to calculate for weld strength

 

[rman487]

Thanks for the help! The connection won't be welded because it's milled out from a puck of steel, so I needed to calculate what is the appropriate reinforcement for the opening of the pilot hole. Thanks so much for your detailed responses. I appreciate it.