Placement of revision symbol when an ECN requires a new page

[mmhorii]

Hello,

What are the typical ways of placing a revision symbol when an ECN requires a new page? For example, suppose you have an engineering drawing that only has one page. Then you need to make a change to the drawing, but your change won't fit on the existing page, so you need to create a new page. In this case, would you put a revision symbol on the new page to alert other people that the page is new and is part of the revision, and if so, where would you put the revision symbol?

Or does the new page not require any revision symbol on it?

I looked through various engineering guideline documents that I found online, but couldn't find anything pertaining to this particular scenario.

 

[drawoh]

mmhorii,

Can you make a note in the revision block that you added a page?

--
JHG

 

[mmhorii]

Hi drawoh,

Thanks for your reply. Yes, adding a note in the revision block is one way of letting people know about the change. But what about the revision symbol in addition to the note? Are there any standards that say anything about revision symbols when adding a new page?

 

[3DDave]

If the process can be changed to eliminate revision symbols you will be much better off. The ECN should detail exactly what changes were needed so the down-stream users should already know what is coming. Comparison with the old drawing will show exactly how it was done. Symbols may or may not do either, but they will always clutter up the drawing and require extra effort.

If the company doesn't have a standard in place to govern this, a copy of which would be sent to any suppliers that work with the drawing, then it's probably not that important.

Best of luck.

 

[mmhorii]

Hi 3DDave,

Thanks; your suggestion to forego the revision symbol sounds reasonable. We don't currently have a standard regarding this case, so we have the freedom to define how to handle this situation. I'll recommend that we not use the revision symbol, unless someone convinces me otherwise.

 

[tbuelna]

Most 2nd sheet drawing formats that I have seen have a place to note the rev level of the current release in the lower RH corner, as well as a rev block in the upper RH corner to provide a brief description of the rev history. An ECN that describes a hard change will state that a new drawing sheet was added. The title block on the 1st sheet will also be updated to read "Sheet 1 of 2".

Personally I don't like rev symbols. A well written ECN should provide all the information about the change the drawing users require.

 

[mmhorii]

Tbuelna,

Thanks for the info about the 2nd sheet drawing formats!

 

[dgallup]

I would place the revision symbol on the first sheet where it used to say sheet 1 of 1 and now says sheet 1 of 2.

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[mmhorii]

Hi dgallup,

Thanks for your post. It's good to hear an argument for a revision symbol, just to move toward a balanced view of the pros and cons.

So if you were to put the revision symbol on the first sheet, where exactly on the sheet would you put it? In the title block?

 

[mtkenney]

if you add a new sheet to the drawing a lot of companies put "this sheet added" as well as the latest rev letter. there are many variables on this. the old rev status block on sheet one is a real mind blower.

 

[mtkenney]

just signed up today. seems like a neat forum. retired last march after 46 years in the business
(25 years as a checker)and enjoy reading and maybe helping out.

 

[mmhorii]

Hi mtkenney,

Thanks for the info! What you say is consistent with the recommendations in ASME Y14.35M-1997, Revision of Engineering Drawings and Associated Documents:

"7.5.1 Adding Sheets. Added sheets constitute a change to the drawing and shall be explained in the Revisions History block. For each new sheet, enter the notation THIS SHEET ADDED in the DESCRIPTION column of the new sheet. The Revision Status of Sheets block and Total Number of Sheets block shall be updated accordingly."
​

As far as I can see in the ASME document, there is no mention of revision symbol. I'm still leaning toward the recommendation of adding an explanation of the added sheet in the revision history only, without using a revision symbol, but I'll try to keep an open mind.

46 years?! I am humbled. Hope you're enjoying your retirement!

 

[dgallup]

mmhorii - Yes, I'd put the revision symbol in the title block box for the sheet number.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[drawoh]

mmhorii,

I don't know how anal retentive your managers are. If your revision block says you added page[ ]2, then page[ ]2 must be what you added when you revised the drawing. Generally, I use the revision triangles when it is not obvious which dimension I changed.

--
JHG

 

[mmhorii]

dgallup, thanks. That seems reasonable. The only minor drawbacks I see to doing that is that it adds clutter to the sheet, and the info provided by the revision symbol is redundant with the description in the revision history block.

In the end, I think the goal of notation should be to make things clear and easy-to-understand, to convey info in a direct and simple way. Your suggestion seems reasonable, and the rev symbol may draw attention to the fact that a sheet was added, but for the sake of keeping documents as uncluttered as possible, I'm not sure if I'll recommend the use of the rev symbol here.

 

[mmhorii]

Drawoh,

Thanks. I like that you say you use revision symbols for cases when it's not obvious where the change occurred. I think that's the key here. When you want to draw the reader's attention to a particular location in the drawing or document, and it's not obvious, then a revision symbol comes in handy.

On the other hand, when a text description of the change leaves no question about a particular area of the drawing, which is the case when a new sheet is added, the revision symbol just doesn't add enough to the readability of a document to warrant its use (at least in my mind).