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Mis-machined Flat Head

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JCrash

Mechanical
Joined
Aug 16, 2007
Messages
26
Location
US
Designing a vessel to ASME BPVC Section VIII Div 2. We have a flat head (SA-516 Gr 70) that has geometry as shown below:

Code:
 ________
|        |
|        |
|        |
|        |
|        |
|        |
 >       |   (These v's are RTJ grooves for a flange face)
|________|
 ________    (This is a thru-hole in the center)
|        |
 >       |
|        |
|        |
|        |
|        |
|        |
|________|

The RTJ grooves were mis-machined. The way we see it, there are two main ways to fix this. I have questions about each.

First - we could weld repair the part. I cannot find an applicable section of the code that specifically applies to repairs due to machining errors (i can find weld defects, material defects, etc). Can anyone provide code guidance?

Second - we could machine out the error and make the thickness where the flange mates thinner. My question here is which thickness does the standard AD-702(a) calc apply to? t1 shown below, or t2? We were using t2 (conservative). Since there are provisions for area reinforcement (which we would meet) and partially drilled holes (which we would meet), wouldn't this groove fall under one of those two? Does anyone have experience with this?

Code:
DETAIL OF RTJ GROOVE

|                                   |
|<--------------- t1 -------------->|
|                                   |
 \                                  |
  |<------------- t2 -------------->|
 /                                  |
|                                   |
|                                   |

 
t2 is correctly shown

weld up the groove and re-machine
 
Thanks vesselfab. Should I treat this like a defective material (AF-104.2)?
 
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