After upgrading our centrifugal compressors to dry gas seals, the lubricant consumption has increased significantly. What could be the reason?
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I have adjusted the pressure of the isolation gas to the upper limit specified by the manufacturer, but it still doesn’t seem to work
Where did you source the dry gas seal from? Oil should not enter the dry gas seal; of course, it’s even less likely to enter the cylinder, so the only possibility is external leakage. Have you found the source of the oil leak? Since increasing the amount of shielding gas doesn’t work, let’s try reducing it. It has a large capacity and high flow rate, and actually has a sucking effect on oil.
High pressure of the isolation gas, if it enters the bearing box, can cause oil to appear in the breathing device of the bearing box
We are using dry gas seals from Sichuan Nikki. The exhaust valve on the bearing housing is indeed leaking oil, but isn’t there a vertical pipe for venting air next to the bearing housing? It shouldn’t cause pressure buildup in the bearing housing. The oil seal at the connection between our compressor and turbine is also leaking oil; even after undergoing major repairs, it still leaks. Since we switched to dry gas seals, there are now many more places where oil is leaking
This post was last edited by windows629 on 2012-10-9 at 15:27. The pressure of the isolation gas is too low, and there is a risk that lubricant might enter the compressor cylinder; raising this pressure increases the number of leaks in the bearing housings of various instruments. What should be done?
What was used for the sealing modification? Floating ring or mechanical seal? Oil leakage is usually caused by maintenance work; there are high points at the locations where leakage occurs, as well as uneven tightening. Try applying more 703 sealant during maintenance.
It is recommended to lengthen the breather tube of the bearing housing and add a demisting screen as well.
With the floating ring modified, the flow direction of the dry gas seal gas toward the lubricating oil system is likely the key factor causing oil leakage from the oil seals, instrument wire connections, and the breather of the bearing housing; however, this issue cannot be eliminated