Hi,

I would like to know if anyone of you have deal with an Air fin Cooler system that includes valves that consent to block any header. When I tried to check the loads in the nozzles by modeling the closure of one of this valves I’m not been able to keep loads below API 661 allowable.

I would like to hear come your experiences about this concern.

"When I tried to check the loads in the nozzles by modeling the closure of one of this valves"

What are the changes because of this??? Post a jpeg or something we need more info.

For example there is a leak in one bundle and the client is not prepared to stop the whole system a repair the leak. He would like to close the valve for that particular bundle and continue working with the rest of the Air Fin.

what are your delta ts and layout? The fact of the matter is this is not an unheard scenario!

My temps are

Operating = 100 C
Design = 204 C

this is the layout:

OK well heres the deal.... Markls original paper was called flexibility analysis... so add flexibility to the system... if it was easy anybody could do the work and they would not need experienced people.

Your stops are going to create a large thermal strain in the system.... send me detailed Isos, pipe specs, structural steel drawings and equipment drawings along with time and material contract and I'll be glad to do the work for you.

Some questions for you...

have you taken into account any nozzle flexibilities?

Do you know what load is creating the overload? Thermal, Sustained or ?

Do you have one moment or shear to deal with if so add flexibility to reduce that?


And most importantly are your temperatures the correct value?

John,

I know that to solve this problem easily one shall give more flex to the system, but that is the point at this time it is not so easy to change all the engineering. All the structures are designed and almost bought.

The system is ok if I consider all the bundles working, but if I start to create scenarios like that of the closure of one bundle, which can be possible since we have the blocking valves I star to face load problems. I did not consider flexibilities in the nozzles. That is exactly the kind of answers that I’m expecting from you, all the considerations that can help me to reduce loads, or demonstrate the client that by the closure of one of this valves the nozzles are going to withstand the increase of the loads.

I tried to insert the picture of the system before, but I believe it did not come through. I will try again later on today.
Regards

nozzle flexibility if you do not have it included will significantly decrease your loads....

I suggest next time around a more explicit input from you will help...

I have tried the following things all to no avail....

My System looks like this etc. etc. the more you tell us the less guessing and more importantly it presents itself better than help I don't know what to do.