An ASME interpretation regarding UW-11(a)(5)(-b) 1

[YuJie_PV]

i am reading Interpretation "BPV VIII-1-19-11", and encounter a problem:
Background: A vessel has a 14" NPS nozzle which is 15mm (0.59") thick with a Category C butt weld between the nozzle neck and a flange. The nominal thickness at the welded joint does not exceed the thickness in UW-11(a)(2), the nozzle is not attached to the shell or heads of vessel covered under UW-11(a)(1),(2) or (3) and the pressure vessel does not fall under UHT.

Question 1: When the vessel is marked with RT-2, is full radiography required for the category C butt weld?

Reply 1: No

Question 2: If the answer to the Question 1 is "No", is spot radiography per UW-11(a)(5)(-b) required to satisfy the RT-2 marking?

Reply 2: No

it's easy for me to understand Quesiton 1, but why the reply is also "No" to Quesiton 2. the nozzle 14" NPS exceeds NPS 10" as specified in UW-11(a)(4), why spot radiography per UW-11(a)(5)(-b) not required?

thanks in advance

 

[Maslov]

UW-11(a)(4) does not apply: the nozzle thickness does not exceed UW-11(a)(2), and is not attached to head and shells falling under UW-11(a)(1),(2) or (3).

UW-11(a)(5)(-b) states:

"Category B or C butt welds [but not including those in nozzles and communicating chambers except as required in (4) above]..."

No other clauses in UW-11(a) apply to category C joints at this thickness. Therefore, if UW-11(a)(4) does not apply, there is no stated requirement anywhere in UW-11(a) to radiograph a category C buttweld on a nozzle when following RT-2.