compressor seal-oil system
compressor seal-oil system
(OP)
Hi,
I am just starting on a new instrumentation project that involves compressor oil-seal system. What I can't seem to determine is what the operating pressure of the system should be. Assuming there is 1000 psi on the gas side, a dp of 45 psi, then the seal oil system would operate at 1045psi, for example. Is this correct? Also, in this example, what would the typical pressure drop be across the bearing?
Thanks
Paul
I am just starting on a new instrumentation project that involves compressor oil-seal system. What I can't seem to determine is what the operating pressure of the system should be. Assuming there is 1000 psi on the gas side, a dp of 45 psi, then the seal oil system would operate at 1045psi, for example. Is this correct? Also, in this example, what would the typical pressure drop be across the bearing?
Thanks
Paul





RE: compressor seal-oil system
Johnny Pellin
RE: compressor seal-oil system
Thanks for the reply. I mis-stated my question. I meant, what is a typical dp, which you answered.
As I understand it, then, the seal oil system must operate at high pressures when the process is high pressure, how is that pressure regulationed in the seal-oil system?
Thanks
Paul
RE: compressor seal-oil system
If the process pressure is very stable, it may be possible to control the seal oil pressure with a simple pressure controller. This requires more attention on the part of the operators make sure that the set point of the pressure controller gives an acceptable differential pressure above the process gas pressure.
For iso-sleeve seals, a different method is commonly used. The seal oil is directed into an overhead vessel that is level controlled. The process gas is directed to the top of that vessel. The height of the level in the vessel is pre-determined to provide the needed differential pressure by virtue of elevation. As long as the level in the vessel is correct and the process gas pressure above the oil is the same as the process gas pressure on the seals, the seal oil differential pressure will be perfect. There are other problems with this method. The process gas is usually in contact with the oil which would contaminate the oil if the process is dirty. A rubber bladder can be used to solve this. But, a bladder failure introduces another failure mode that can have very serious consequences.
Johnny Pellin
RE: compressor seal-oil system