Change Classifications

[cadfreak]

Can someone please explain Class 1 and 2 changes for drawings?

Thanks!

 

[MadMango]

Class I (Non-interchangeable Change)-
Items in this category will not physically or functionally meet product specifications as a direct replacement item for all applicable applications using the previous revision. Items in this category require new part numbers to be assigned.

Class II (Interchangeable Change)-
Items in this category retain the physical and functional product specifications to act as direct replacement items for all applicable applications using the previous revision.


"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[TheTick]

Is this an ANSI definition (or some other non-private standard)?

 

[KENAT]

Isn't it something like MIL-T-31000, I tried to find it in the ASME specs a while ago and had trouble, I'd appreciated if anyone can give the ref.

One thing that occasionally gets missed on Class 1 is that the changes must be both forward and backward compatible. i.e. not only must the new rev replace the old but if necessary the old rev can replace the new.

 

[MadMango]

Sorry, I should have noted it was non-standard, but based on a standard. I'm trying to find the mother document.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?