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Weld Repair and "E" value used in Head Calc

Weld Repair and "E" value used in Head Calc

Weld Repair and "E" value used in Head Calc

(OP)
A small nozzle hole was incorrectly placed and repaired by using the material drop from the correct hole as the plug for the incorrectly located opening, and the weld was LP tested.
If the calculations were originally performed using a seamless ellip head with "E" value noted below...
Efficiency, Longitudinal Seam 0.85
Efficiency, Circumferential Seam 0.65

Do I have to change the Long Seam E value to 0.7 because of the weld repair?

RE: Weld Repair and "E" value used in Head Calc

NO.
Regards
r6155

RE: Weld Repair and "E" value used in Head Calc

(OP)
Thank you r6155, the shop AI insists this must be done and I've stated that per UW-34 it does not. The AI isn't buying it and this AI falls back on Sect.VIII Div.1 U-2 (e)whenever asked to explain why?
Do you by chance have another section from the code that addresses why this isn't necessary?

RE: Weld Repair and "E" value used in Head Calc

See UG-11(a)(3)(b). If the head is considered a material, and assuming it is governed by SA-20, see SA-20 9.1 & 9.4.

RE: Weld Repair and "E" value used in Head Calc

Sorry,I forgot to say: to restore the condition of seamless head you must 100% RT the repaired hole.

Regards
r6155

RE: Weld Repair and "E" value used in Head Calc

Depends of the size is f the old it before welding. It was not addressed in the post. If a small hole no further calcs needed.
Seamless: no seam it's not a segmented head. Openingse are to be compensated.

RE: Weld Repair and "E" value used in Head Calc

(OP)
Its a 2" dia hole, and it was not x-rayed only LP tested.

I did some searching and found Interpretation VIII-1-86-22. The status is Out of Date and notes that paragraph UW-34 has since been added, specifically addressing the closure of spin holes created by forming. It considers the welds to be unclassified joints, not to be considered for determining the "E" value for calulating the head thickness.

Which was my response to the AI, however the argument that the hole being repaired is in fact not a SPIN HOLE. Why does it matter how the hole got there, a hole is a hole, it's being plugged with the material ht# taken from the new hole, welded the same as required for a spin hole and LP tested the same as a spin hole.

Our problem is that the thickness requirement exceeds the actual min thick when we change the E value from 0.85 to 0.7, and the heads have to be scrapped. I'm trying to avoid this waste.

RE: Weld Repair and "E" value used in Head Calc

My solution: Cut again the hole and install threaded half coupling 2"

Regards
r6155

RE: Weld Repair and "E" value used in Head Calc

bayardwv, lets review your choices:

1) You can scrap the head
2) You can engage in a p#ssing contest with your A.I.
3) You can shoot the repair and get on with life.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: Weld Repair and "E" value used in Head Calc

(OP)
Thanks to everyone for your suggestions.
I was aware of my options when I started this thread.
I simply needed to let them know if the heads were acceptable per the AI's request to reduce the "E" factor.
In the end it's on the Shop to deal with it, however I'm a "big picture" type person and was looking out for the Corporate bottom line.

Again thanks to everyone for your comments and suggestions

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