Shannon,

We have had several conversations here on the forum about 'failing the weld' and/or 'failing the welder'. 

While one does need to exercise great caution in attitude and thus how we approach the job, I felt I understood your comment more of a way of expressing how you felt about the difference between being the Judge and choosing the worst side to be expanded and that doing so gave the appearance of approaching the coupon with an attitude of failing the weld and thus the welder.

Not so.  When supported by direction in the code it is obvious that the code has approached this with the idea of making as sure as possible that each weld has the highest potential of being of the highest quality possible even though speaking in terms of minimum standards.  If they wanted absolute they would allow no discontinuity at all and every weld would have continuous VT with support from 100% RT, UT, and MT.  But that would be excessive under most circumstances. 

But to get the odds into a reasonable area of acceptable work completion we have standards and codes that lend to minimum requirements starting with allowable/acceptable discontinuities.  So the welder is tested to make sure he can comply to a minimum standard working to a proven WPS written to specs that meet minimum qualifications for preheat, process, welding parameters, materials, etc. 

Once we know the welder can do the job required, have a proven WPS, and materials to use from a selected group then we insert a reasonable amount of inspections to insure compliance with all the specifications. 

It can easily be proven that slightly higher preheats will vastly improve the ratio of success.  But, one has to draw lines somewhere and the lines are definitely MINIMUM standards.  The same can be said for other aspects such as heat input, having a max interpass temp as the seismic codes do, etc.  All would improve the safety factor multiple times over.  But, where does cost, history of success vs failure, public safety vs company profits, all meet a good balance?  Thankfully, that is not a decision I have to make.  Just follow the code as best I can. 

After reading Allan's post I re-read Clause 4, the Commentary, and checked out the notes on the applicable tables and figures.  I don't see where it actually states that root and face bends are definitely chosen the same as side bends.  But, as I said previously, is it unreasonable to 'ASSUME' (gotta love that word) that I CAN even if it is not required.  And, they do not tell you a method of choosing which coupon is which.  My choice.  This is how I choose.

He Is In Control, Have a Great Day,  Brent