2019 UCS-66 for flanges

[ENG2194]

I know the 2019 code changed the UCS-66 curve for as-forged flanges and now there is a series of stipulations to have a lower MDMT for flanges. My question is does UCS-66(C) prohibit the use of UCS-66(b)(1)(-c) for a temperature reduction below 0°F for as forged ferritic flanges?

 

[ChiangJaron]

Dear ENG2194:

The code provided any table is convenience for checking MDMT what we need.
It's not only one way to exempt impact test.

You may change your mind firstly and refer the steps in my understanding as,
First step : you should assume all impact test are required.
Second step : Find "any" one rule to exempt impact test.

The method could apply in PWHT judgement, too.