I used nozzle modeling API 650 for nozzle flexibilities. Caesar II address this issue to Appendix P as per stated in Mechanical Engineering News (Dec. 1993).As per API 650, appendix P, it states that the appendix is recommended only for tanks larger than 36m (120 ft). My question are
1. How about those tanks less than the diamter specified in the appendix, does Caesar II program address also for smaller tanks?
2. If that it so, what alternative method being used?
3. Instead of using modeling nozzle by API 650, I will use WRC 297 for nozzle flexibility because tank can be treated also as cylindrical shell, does it possible and the result is same also with API 650?

Any suggestions/comments are highly appriciated

Hello Nald,
One of the purpose of using API 650 is to consider the nozzle rotation and radial outgrowth of bottom nozzle because of the bulging effect of the tank. This will considerable impact the loads on nozzle due to piping configuration.
In case of WRC 297 these are not addresed.
What i have done is if in case of considerable large dia tank (may be less than 36 m dia) use the same API 650 for both nozzle allowables.
Please correct me if I am wrong.

Regards,
Faizal H

Nald,

1)CAESAR II implements API-650 Appendix P, and is therefore subject to the limitations in scope as set forth in this appendix.

2) See PVP-1279, a paper published some years ago discussing the stiffness and load limits for smaller tanks. CAESAR II doesn't address this, but this is an alternate method.

3) Maybe, you'll have to check the limitations of WRC-297 against your particular dimensions.

There is always the FEA route.

Richard AY,
Thank you very much sir for the informations and sugestions.
API 650, eleventh edition address WRC 297 as alternate procedure for the evaluation of external loads on tnak shell opening, does it reliable?

Faizal H,
Tanks smaller than 36 m (120 ft) in diameter behave differently (like a cylinder-cylinder intersection), and the results obtained from Appendix P may not be applicable or accurate.

No it isn't reliable. There "were" so many errors in this section I couldn't even work through their examples. 11th Edtion Addendum 1 deleted this section.

Thank you very much again sir..