QUOTE(00r101 @ Aug 26 2014, 08:21 AM)
QUOTE(76-914 @ Aug 26 2014, 11:06 AM)
Air is OK. Doesn't change the indicated pressure reading.
Ahhh, My high school physics says that a gas is compressible but a liquid is not as much. So air in the line will be compressed a bit as oil pressure changes. But whether it will make a huge diff in the oil pressure reading I do not know. Air in the line will start off at 14.7 psi so how much it will compress at say 60 psi i might be minimal
The pressure from the oil side in the line will be X psi. This will compress the air until the pressure from the air side is also X psi.
With air in the line, the gauge will move a little slower (since oil will have to flow up/down the line as the pressure changes), but once it's stable, the air pressure will match (precisely) the oil pressure.
The only thing a little air in the line will do is slow down the response rate of pressure change. the air will act as a capacitance just like an accumulator will in a hydraulic circuit.
Barefoot