Drawing standards
Drawing standards
(OP)
I am going round and round with our Eng Mgr over our General Arrangement (GA) drawings. We build horizontal pumps that mounted on a skid, we dimension the location of the intake and discharge flanges, on our GA drawing, but we do not have a "tolerance block" in the tile block area of our drawing, and we do not have a +/- tolerance on the location dimensions. With that being said, our Eng Mgr tells me, since we do not have a "tolerance block", that all dimensions on the GA drawing are REFERENCE ONLY, but no where on the drawing do we state this. Is the Eng Mgr correct or not ??





RE: Drawing standards
Your EM's interpretation is whatever (s)he wants it to be, but if there is no direct or indirect vector to a standard for interpretation, it becomes inevitable that a customer will disagree with your EM's interpretation, and that always turns out badly.
Mike Halloran
Pembroke Pines, FL, USA
RE: Drawing standards
“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV
RE: Drawing standards
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Drawing standards
What would you do with a warranty claim for nozzles that were 1/4" off from the drawing? 1/2"? 1"? Customer's problem? How would you fight a backcharge if piping was fabricated per your GA and customer had to rework once the unit arrived? You can't exactly say it is "close enough" if in fact, it isn't. Using ambiguity as a defense will only work one time per customer, if it works at all. Not a very good plan.
Ask a lawyer if 12.0" means 12.0", or 12.25".
RE: Drawing standards
The reference dimensions are (or should be) derived from other drawings along with their applicable tolerances.
“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV
RE: Drawing standards
Independent events are seldomly independent.
RE: Drawing standards
Paul
calgary.spedweb.com
Piping Design Central
www.pipingdesign.com
<a href="http://www.gulfpub.com/product.asp?PositionID=camp...">The Planning Guide to Piping Design</a>
RE: Drawing standards
Reminds me of the kind of engineer that always writes numbers to an accuracy of 5 significant digits, the first one wrong.
Independent events are seldomly independent.