Pressure from Thermal Expansion
Pressure from Thermal Expansion
(OP)
Hi, I am looking at a pipe (Contents are fuel oil) with a design pressure of 5 bar, the pipe also has a thermal relief valve set at 19 bar. I need to re-rate the pipe, can I use the fact that the thermal relief valve has lifted in lieu of a hydrotest ?, if the thermal relief has lifted is the system likely to have been subjected to 19bar?, why are TRV's sometimes set at higher pressures than design ?
Thanks Wilg10
Thanks Wilg10





RE: Pressure from Thermal Expansion
The design pressure is a value which is selected (usually by the Process engineer) and usually relates to the maximum operating pressure + a design margin. All components in this system should be designed for at least this pressure. In this case the pipe is "good" for 19bar which far exceeds the design pressure of 5 bar so is just fine. I don't know your setup but there could (in theory) be other components in the system which are only "good" for 5bar.
What was the original system hydrotest pressure? Was it 7.5bar? Or did they test to 28.5bar?
RE: Pressure from Thermal Expansion
RE: Pressure from Thermal Expansion