dear Sir,

Please let me know how to run the intermediate head in PV Elite?

in my understanding i have considered as below

for intermediate head: i considered external pressure will be internal pressure of bottom column so please confirm? or is there any other method?

or please let me know how to calculate using differential pressure in PV Elite?

thanks,

BR,
Sameer

Hi BR

For the intermediate head, all you have to ask yourself is what is the pressure acting on the outside of the head, and what is the pressure acting on the inside of the head. If you keep that straight, the calculation for the head will be correct.

dear Mr. Ray,

Thank you for your advise but I am doing same & getting very high thickness so our client suggested me to use differential pressure on intermediate head and i dont know how to use this differential pressure in PV Elite. so please advise me, is there any mehtod i can do in PV Elite.

Best Regards,
Sameer

Hello Sameer

A pressure on the convex (outside) of a head will invariably require a thicker head than if that same pressure were applied to the concave (inside) of the head.

Sameer,

Please do ask the following question with your process people (before proceeding with design).

a) Are both compartments are directly connected with each other with a interconnecting pipe (without a control valve in between the connection?

If the answer is yes i.e. both compartment are connected with a interconnecting pipe without a control valve, then one thing is sure that there would not be any differential pressure acting on either side of intermediate head because during commissioning or decommisionning or in service both compartment would get pressurized or de pressurized at the same time.

b) If both compartments are directly connected with each other with a interconnecting pipe (with a control valve in between the connection) then again ask process people what wolud be the max differential pressure we are expecting in the equipment.

In reply to question that How to appy differential pressure in PVELITE?

Ans :Input the Value(as recieved from your process deptt.) of differential pressure in both (internal & external pressure) tab for Dish head.

Higher of them will be your required thickness.

gentlemen,

Thank you very much for your kind support. I have received folloiwng information from our clint i.e. as follows,

* 32-C-06 (top vessel) and 32-D-15 (bottom vessel) have an inter-connecting pipe with no block valves, this results in a differential( internal & external) pressure of 0.33 bar(g), this combined with a liquid full upset condition results in a 2.911 bar(g) worst case internal operating pressure.

and please note that, in client data sheet 35.65 barg is given for int pressure & ext pressure is full vacuum.

Now please advise me, can i use 0.33 barg in pvelite program both int & ext pressure?

Hello sameercnn

When you refer to 0,33 barg, I assume you asking if you can set the units to bar. Just select 'bars' from the units drop down list.

Dear Mr. Delaforce,

I did not understand your reply so please explain it once again to understand it better.

my question is shall I enter 0.33 barg pressure in int & ext pressure input data in PV Elite program or is there any other method?


regards,
Sameer

Sorry Sameer

Yes, if the two chamber have a design pressure of 0,33 bar, you should enter this pressure on both sides with this value.