range of groove angles

By Lawrence (*****)

Date 09-28-2007 11:14 Edited 09-28-2007 11:29

#1 The detailer is allowed + 10 and -0 and still have the joint pre qualified... So he can go 45 - 65 on the print.

#2 The fitter will only see the detail (print) so he can go + 10 and - 5 from what the detailer provides him.

So the drawing or WPS will provide an angle (as detailed) which has been given the lattitude mentioned above. #1

When the welder is given the drawing or WPS. He may take the "as fit up" lattitude of what is mentioned in #2

So the 40-65 you mention is what the code allows as a maximum and still remain prequalified... As detailed *and* As fit-up

The detailer cannot put the 40 or the 65 on a detail or wps unless his + and - are zero, which is not very fair to the fitter.

It also could be less than 65 if the detailer does not put the maximum into his detail :)

Clear as mud?

By pax23

Date 09-28-2007 16:32

Well put. Too many individuals feel the code allows them to stack these tolerances during fit-up which is not correct.

By ctacker (****)

Date 09-28-2007 17:38 Edited 09-28-2007 17:49

thats what i thought, but according to the code clinic it is 40-55, that goes against 3.12.3 which states you can stack the tolerences!
added -but only if its detailed at +10

By pax23

Date 09-28-2007 18:39 Edited 01-25-2011 16:25

Ooops. I reread Lawrence's reply and disagree with the numbers in his example. I agree with the words but the numbers provided in the example do not match my understanding. I disagree with ctacker's assertion that 3.12.3 allows stacking of the detailed and fitup tolerances. To make things clear I will use numbers and several examples to try to explain my understanding.

I'm only going to look at groove angle, the other joint dimensions should be handled the same.
Example #1 (BC-P6, SMAW)
Nominal (target/default): 45°
Detail Drawings: 45° (detailer could have chose anywhere between 45° - 55°, ie, +10°, -0)
Fitup Tolerance: 40° - 55° (ie, +10°, -5° from detailed 45°)

Example #2 (BC-P6, SMAW)
Nominal (target/default): 45°
Detail Drawings: 50° (detailer could have chose anywhere between 45° - 55°, ie, +10°, -0)
Fitup Tolerance: 45° - 60° (ie, +10°, -5° from detailed 50°)

Example #3 (BC-P6, SMAW)
Nominal (target/default): 45°
Detail Drawings: 55° (detailer could have chose anywhere between 45° - 55°, ie, +10°, -0)
Fitup Tolerance: 50° - 65° (ie, +10°, -5° from detailed 55°)

By ctacker (****)

Date 09-28-2007 20:07 Edited 09-28-2007 20:09

I never been good at explaining things,but that is exactly as i see it, im not saying if its detailed at 55 then 40 to 65 is the range, i know it would be 50 to 65, but the question of what the range of groove angles is dependant on the detail drawing, so the minimum is 40 if detailed at 45 and the maximum allowed would be 65,considering the detail was 55!
edited- so that would give the range of 40-65 wouldnt it?

By ssbn727 (*****)

Date 09-29-2007 23:28 Edited 09-29-2007 23:39

Hi Ctacker!

Please correct me if I misunderstood the premise of your question because, I'm going to quote you verbatim from the summation of your question...

"what exactly are the ranges of prequalified joint BC-P6, (as fit up?)
D1.1 shows 45 deg."

1.) "as detailed +10 -0"
2.) "as fit up +10 -5"
"so if you have +10 as detailed, and +10 -5 as fit up, wouldnt that give the range of 40 - 65 deg?"

If you are only concerned with the as fit up tolerance range, then the minimum would be 40 and the maximum would be 55 degrees.

However, if the detailer has already given a +10 from the original 45 degrees, one then has up to 10 degrees more to include to the original unit of measurement of 45 degrees before one implements an "As fit up" tolerance which would be: -5 to +10... the result would be 45 +10 then an additional +10 degrees from the "as fit up" tolerance range allowance.

Remember that one also has a minimum tolerance range allowance of -5 degrees which would be subtracted from the original 45 degrees, resulting in an overall tolerance range allowance for "as fit up" to be 40 to 65 degrees, and the "as detailed" tolerance of only being: 45 to 55 degrees

So practically speaking, one could end up with a "As fit up" tolerance range for a 45 degree angle of: 40 to 65 degrees so long as the "as detailed" +10 is included with the +10 from the "As fit up " tolerance as well as the -5 from the "As fit up " tolerance is to refer to the original 45 degrees, which would therefore allow for a minimum tolerance of 40 degrees... So it all depends on what the detailer's range of tolerance may allow before one calculate's the "as fit up" range of tolerance for a specific measurement as in this case would be in degrees.

I guess we're lucky that we're not being asked to be too precise whereby minutes and seconds are also being included as units of measurement also ;)

Respectfully,
Henry

By ctacker (****)

Date 09-30-2007 00:01

Thanks for the reply Hank, like i said i am not the best to be giving descriptions, i need to work on that!
I was just qouting from a question where i answered 40 to 65 and the right answer was 40 to 55,
just wanted to know if i was the only one that assumed 40 to 65 givin the minumum and maximum allowed for that joint,
assuming the detailer goes 0,that gives a 40-55 deg. and if the detailer maxes at 55 that gives 50-65 so to me the "RANGE" is 40-65,
Which is the very minimum and the very maximum allowed for that joint!

By GRoberts (***)

Date 09-29-2007 01:11

I agree with Lawrence. (Except did you mean on #1, that the detailer can go from 45-55 deg?) Nothing in AWS D1.1 says that the detailer or WPS can't give a range of angles. If you apply the as-fit up tolerances to that, it really can be 40-65.

By Lawrence (*****)

Date 09-29-2007 04:09

Right