Turbine oil used in steam turbines, gas turbines, blowers, vacuum pumps and hydro turbines is designed to shed water.
Water can be introduced into the turbine oil through lube oil cooler failures, damaged heat exchancers, seal leaks, improper cleaning practices, & contaminated turbine oil.
Water content in turbine oil should be no greater than 150 ppm. Unmanaged water ingression will require derating turbine output, an unplanned outage, a turbine trip or bearing “wipe”.
A paper mill with a small low pressure steam turbine has never ending issues with water ingression into the turbine oil. Ageing coolers and tired seals are projects for planned outages but when the planned outage is not soon 800 ppm water needs attention and a work around is needed to keep operating.
A properly sized Coalescing unit was installed on the turbine oil reservoir as a kidney loop. Turbine oil is effectively separated from free undissolved water through the coalescing process. Removing the “free” undissolved water from turbine oil yields turbine oil water content of 150 ppm moisture content – ideal oil condition.
The Coalescing unit reduced water content to 150 ppm in 8 hours and is now kept in continuous service maintaining low moisture content in the turbine oil permitting safe turbine operation with time to plan maintenance repairs in an orderly fashion.