Interpretation of UCS 5(b)

Neither. Please read the original statement more closely.

OK,What is your interpretation?

There may be allowable exceptions "as provided elsewhere in this Division".

That means,

1.As long as no allowable exceptions are not available in this division (Sec VIII-Div1), oxygen cutting of carbon and alloy steel having carbon content more than .35% are not allowed?

OR

2.As long as no allowable exceptions are not available in this division(Sec VIII-Div1) , Oxygen cutting of carbon and alloy steel are not allowed irrespective of carbon content?

1. No.
2. No.

Your expressions have not accounted properly for double negatives (no...not), and thus are not correct understandings. Moreover, they are more complicated than the clause(s) you are trying to understand.

Yes you are right. Thank you for pointing out the problem. I have used one extra 'No' in the sentences, which had altered the entire meaning!So,I reword it.

As long as allowable exceptions are not available in this division (Sec VIII-Div1), oxygen cutting of carbon and alloy steel having carbon content more than .35% are not allowed and carbon steel/alloy steel below 0.35% carbon percentage can be cut by oxygen. Is it correct interpretation?

Yes, though it doesn't explain why.

Thanks.Getting the right interpretation of code is valid.Remaining story is available in metallurgy books.