Previous work usage

[JamesBarlow]

My questions is specific to Section VIII Div 3, but any help or insight would be appreciated.

The company I work for has been in the High Pressure Vessel business for over 30 years. Prior to division 3 most of our vessels recieved a state special.

My question is that the code does allow for anecdotal evidence to be supplied for the integrity of a vessel. ie. a vessel of this design has been in service for x many years with no problems. Has any one used this, and does it's use allow for vessels that do not pass the current code.

We have designs for 30ksi and up vessels that have been in service for over 500,000 cycles, yet to design them to the current code would require them to be 2-3 times larger than the original.

Any insight in this, or a push in the right direction, would be helpfull.

 

[Tankman650]

James,

I am not familiar with Div 3 but I know that it is an alternative. Since the pressure is over 3000 psi you must use Div 2 at the least.

Under Div. 2 rules, you must have the calculations certified by PE. He can determine the stress state using finite elements and nonlinear materials. Fatigue may also be a factor.

The use of the reason "We have always done this" will not get you far with the AI in most cases. Usually the final say in the documentation falls with the AI. You should call him and discuss this with him and his carrier.

HTH