API 620 nozzle neck cal. and external pressure cal.

[prasit]

Hi experts,

Please anyone suggest me about API620, as I am quite new for this code.

1. How can I calculate nozzle neck thickness? According to the code, it specifies only min. thk of the neck but nowhere indicate the calculation method.

2. If the tank is subjected to partial vacuum, How can I calculated the required thickness for this vacuum.

Thank you
Prasit

 

[JoeTank]

Calculate the nozzle neck minimum thickness as a cylinder subject to internal pressure... t = PR/SE

Vacuum loads are not addressed by API-620. You might want to review API-650, Appendix V for vacuum related design issues.

Joe Tank