Efficiency for Nozzle Thickness Calculation. 1

[szoghbi]

Hello!

When nozzle thickness is calculated in many examples on Appendix L, the efficiency equals one regardless of the type of joint or its degree of Radiographic Examination. I would like to know why it is so?

I understand that if a joint between the shell and a nozzle (Joint Category D) is Type Nº1 and full radiography is performed, the efficiency for calculating the nozzle thickness is E=1. But if it is a Type Nº2 (full radiography), shouldn’t the efficiency be 0.9, according to Table UW-12?

Thank you...

 

[prex]

No, the efficiency of the joint relevant to nozzle reinforcement calculations is that of a joint in the shell crossed by the nozzle (and normally there isn't one): see definitions in UG-37.
Normally a joint between the nozzle and the shell is not RX tested, as the interpretation of results would be very questionable (though this depends on actual geometry). Anyway the efficiency of this joint is unrelevant to reinforcement (and normally to any other) calculation.

prex

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