Delete Old Revision Clouds on Drawings When Doing New Revisions?

[kkline116]

TL;DR Summary

According to ASME, do you delete your old revisions clouds?

Hello,

I know I read this somewhere in ASME standards, but I can NOT, for the life of me, find it again.

I believe it says you're supposed to delete old revision clouds on a drawing when putting a new revision on the drawing.

I read Y14.35 "Revision of Engineering Drawings" 2 or 3 times and I checked Y14.1 Engineering Drawing Practices, Section 4.4 "Revisions of Engineering Drawings and Associated Lists", but can't find anything that says what we're supposed to do with old revision clouds when adding a new revision.

Does any know where I can find the ASME standard on what we're supposed to do here?

Thanks in advance!

 

[Tom.G]

You might try Y14.100. Page 9 in the PDF:

1.1 Scope
This Standard establishes the essential requirements
and reference documents applicable to the preparation
and revision of engineering drawings and associated
lists. It is essential that this Standard be used in close
conjunction with ASME Y14.24, ASME Y14.34M, and
ASME Y14.35M.The Standard is available at:
http://gost-snip.su/download/asme_y14_1002004_engineering_drawing_and_related_documentati

I know the above link looks damaged but it works when I paste it into the address field of the browser.

In your PDF reader, search for the string: revis
and start reading for clues.

The little bit of drafting standard I've been involved with is:

• Always keep the old revisions
• Each revision must contain ALL the information to build to that rev.
  Don't forget the parts list, some items may also need a revision
• Since each rev is stand-alone/complete, there generally is no reason to denote/highlight earlier revs; they just add useless clutter, especially when nested! In the real world, exceptions may occur which can often be covered by a note.

That's my non-expert two cents worth anyhow.

EDIT: Forgot to add that a table/list of the Revision History with brief description is often included on a drawing... and is useful.
/edit

Cheers,
Tom

 

[The Fez]

I don't know of any code standard, but in my opinion, the rev clouds are not a part of the actual design per se, and therefore do not need to be preserved. Rev clouds are a way to identify the parts of the drawing that have changed to assist field personnel during construction. We generally remove all rev clouds during the As-built process. Once the drawings represent the new "reality," old clouds and deleted linework, are just clutter. I have worked on drawings with 30+ revisions over the years, and it would be completely unreadable if everything were preserved on the master drawing. Of course revision blocks should always be maintained and updated.

However, as a consultant, I have worked on projects where drawings are being modified for several parallel projects to be constructed concurrently, and often these projects are designed by different engineers, even different consulting firms. It is important to have clouds to delineate who's design is who's, and add "for rev X only" qualifiers under your stamp for liability reasons.

Of course, record copies of each rev should be preserved according to the Engineering standards of your jurisdiction.