Accumualtion Pressure
Accumualtion Pressure
(OP)
Dear all,
can any onr tell me that the accumualtion pressure considered for thermal expansion case.
My case is , there is heat exchanger shell side hydrocarbon and tube side cooling water. i wanted to have thermal expansino valve on tube side. my exhanger is designed for blocked outlet condition 10/13 rule is applied. so i have set the PSV at tube side design pressure 10 kg/cm2(g) . my query is what shoul be the maximum accumualation pressure to considered.
can any onr tell me that the accumualtion pressure considered for thermal expansion case.
My case is , there is heat exchanger shell side hydrocarbon and tube side cooling water. i wanted to have thermal expansino valve on tube side. my exhanger is designed for blocked outlet condition 10/13 rule is applied. so i have set the PSV at tube side design pressure 10 kg/cm2(g) . my query is what shoul be the maximum accumualation pressure to considered.





RE: Accumualtion Pressure
Good luck,
Latexman
RE: Accumualtion Pressure
Good luck,
Latexman
RE: Accumualtion Pressure
I hope your case is cooling water blocked in tube side and maximum hydrocanbon flow on shell side.
If the tube head is designed per ASME Section 8, Div II, then maximum 10% accumulation or 110% of MAWP as advised by Latexman.
RE: Accumualtion Pressure
RE: Accumualtion Pressure
Good luck,
Latexman
RE: Accumualtion Pressure
This statement worries me and I have to ask if you know what you are doing. What you did NOT say is that you have designed the exchanger such that the tube side design pressure is >= 10/13 of the shell side design pressure. That would have indicated a good design. Instead, to me you are just saying that you'll set the tube side PSV at 10/13 of the shell side (...unknown). If you mean what I said would be a good design, then no problem. If not, then I'd like to know what the TS & SS design pressures are.
Doug
RE: Accumualtion Pressure
Can you advise the heat exchanger design code ?
RE: Accumualtion Pressure
RE: Accumualtion Pressure
"We don't believe things because they are true, things are true because we believe them."
"Small people talk about others, average people talk about things, smart people talk about ideas and legends never talk."
RE: Accumualtion Pressure
Your response make this thread interesting.
First, I understood "ASME 1 code" mean "ASME Section I Power Boilers". If so please check ASME Section I,
- Paragraph PG-67.2 it defines the 6% ,maximum Boiler Overpressure requirement.
- Para. PG-67.3, One or more Safety Valves on the boiler proper shall be set at or below MAWP. If additional valves are used the highest pressure setting shall not exceed MAWP by more than 3%.
I hope above statement still valid with latest ASME (i don't have latest ASME Section I with me).
So in many event, the overpressure shall be mentioned together with the design code.
sheiko,
Hope this post "Two-third (2/3) rule or Ten-thirteen (10/13) rule ?" and associate links answer your question.
RE: Accumualtion Pressure
2/3 =0.666 and 10/13 =0.769 . 10/13 will give you a higher design pressure and API 521 also recommends. 10/13 only...