Design Pressure and Temperature
Design Pressure and Temperature
(OP)
Could you please tell me what are the differences between the following terms?
Upper operating pressure/temperature
Lower operating pressure/temperature
normal pressure/temperature and operating pressure/temperature
Thanks in advance
Upper operating pressure/temperature
Lower operating pressure/temperature
normal pressure/temperature and operating pressure/temperature
Thanks in advance





RE: Design Pressure and Temperature
you're asking some pretty basic questions here without any explanation of your role, location, support network, etc. Please provide a bit of background.
All these mean are gradually increasing number from low, medium and high and all the parameters can vary within those bounds without causing an issue.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Design Pressure and Temperature
Flow comes from some land wells. Gas = 10 MMscfd. CGR = 10 bbl/MMscf condensate, no water is produced. Arrival T = 5 to 30°C.
Gas is 2% CO2, 90% C1, 1% C2, 2% C3, 2% iC4, balance C5+
Condensate: density 700 kg/m3
FTHP = 50 barg
CITHP = 120 barg
RE: Design Pressure and Temperature
Design pressure for a pressure vessel should be the pressure never exceed. (actually pressure vessel really should have a MAWP calculated which might be higher, but same thing - it's a maximum pressure at a certain temperature which cannot be exceeded - no additional margin is allowed.
Pressure alarms, trips and relief settings normally need a margin below DP or MAWP, hence your upper operating pressure/temp where operation is possible before the units alarm and trip.
normal is what you expect the majority of the time
Lower is the lower end of "normal" and for a separator might result in high velocities and poor operation
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Design Pressure and Temperature
If I have the max/normal/min operating pressure, then why I need to calculate also design max/min pressure or temperature? What is difference between max/min operating P/T and max/min design P/T ?
RE: Design Pressure and Temperature
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Design Pressure and Temperature
RE: Design Pressure and Temperature
The ASME B&PV Code Section VIII, requires a certified relief device (or devices)for every Code vessel.
The setting of that device shall be not greater than the MAWP for the vessel. In practice, unless there is a good reason for a lower pressure setting, the MAWP is most often used
http://www.nationalboard.org/index.aspx?pageID=134...
This does not prevent the use of devices on the system set at lower pressure to facilitate process control
MJCronin
Sr. Process Engineer
RE: Design Pressure and Temperature
I know that, my point above was that if you set the RV at the MAWP, then the maximum or upper operating pressure needs to allow for the accuracy of the relief valve (sometimes 10%) set point and setting of high and high high pressure alarms and trips.
Hence for a vessel with a MAWP of 10 barg, it is unlikely that the upper operating pressure would be much above 9 barg.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Design Pressure and Temperature
RE: Design Pressure and Temperature
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Design Pressure and Temperature
RE: Design Pressure and Temperature
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.