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CCG
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- Why pressure falls after rapid pressurization
Hi all,
A question on the physics behind rapid pressurization (relatively high pressures e.g. 300 bar) and perhaps transients in systems. For simplicity, imagine that we only have a piece of pipe with an initially closed valve on one side and a pressure indicator on the other side. The current pressure in the pipe is atmospheric (~1 bar, zero over pressure). Further, on the other side of the valve I have connected a high pressure line. If I open and within very short time close the valve, the pressure indicator would first quickly rise and indicate same pressure as in the high pressure line. Just after closing the valve, the pressure indicator drops to a value less than the pressure in the HP line.
I the valve would remain open for a longer period of time before being closed, the effect can not be observed.
Could someone explain the physics behind this? Do temperatur variations during the pressurization have to do with it?
Many thanks!
C
A question on the physics behind rapid pressurization (relatively high pressures e.g. 300 bar) and perhaps transients in systems. For simplicity, imagine that we only have a piece of pipe with an initially closed valve on one side and a pressure indicator on the other side. The current pressure in the pipe is atmospheric (~1 bar, zero over pressure). Further, on the other side of the valve I have connected a high pressure line. If I open and within very short time close the valve, the pressure indicator would first quickly rise and indicate same pressure as in the high pressure line. Just after closing the valve, the pressure indicator drops to a value less than the pressure in the HP line.
I the valve would remain open for a longer period of time before being closed, the effect can not be observed.
Could someone explain the physics behind this? Do temperatur variations during the pressurization have to do with it?
Many thanks!
C