ASME VIII div.1 queries! 1

[gbratis]

Hi everybody.
Two additional queries for you.
1)Do I have to perform a reinforcing area calculation for a 2" nozzle in a ASME VIII div.1 calculation? Is the minimum nozzle thickness according to UG-45 the only limitation for a nozzle EQUAL or smaller than NPS 2" for an ASME VIII calculation?
2)What provisions should be made when a nozzle O.D is equal or greater than the 1/2 of a shell's O.D.Is a calculation according to ASME VIII div.1 Appendix 7A, adequate? Which is according to your experience the most efficient way to face this circumstance? A thick nozzle with an even thicker pad or an integrally reinforced nozzle?
Thanks in advance.

 

[gr2vessels]

gbratis,

1) No additional reo is required according to UG 36. Yes, the only limitations is UG 45, remember only to include 12.5% thinning/ manufacturing allowance for the pipe wall thickness.
2)That is Appendix 1, Clause 1-7. Depending on the nozzle and vessel size, shell thickness and lots of other conditions, use pads for smaller openings and lower design temperature/pressure, use integrally reinforced nozzles when is more cost effective than to increase the shell thickness. Also, depending on the service, usualy no reo pads are allowed in hydrogen service, sour service, low temperature service or cycling service. Typically, is cheaper to use a reo pad, but are limited to ordinary service, eg. an air receiver. However, the integrally reinforced nozzles are associated with high pressure, temperature, special fabrication requirements, PWHT, etc, hence relative high overall costs.

Unfortunatelly, there is no quick fix for your question, all the above are only a fraction of the potential design conditions for those nozzles.

Cheers,

gr2vessels

 

[GenB]

Those small nozzls and fitts have to be calculated to a seamless pipe
then depending on the type of welds chosen you decide to reninforce or use thicker metals on nozz or base matl.so the final answer is yes 1- the nozzles have to be calc and then the reinforcing is to be proven.

genb