Is anyone out there using near-line systems to filter their hydraulic oil?

[BigOilHatesMe]

I'm trying to gage various industries' appetite for deploying filtration systems for large-use hydraulic machines (lubricating, power transfer, washing, etc.) This includes machines like stamping presses, diecast or injection molding machines, wind turbines, and others that use hundreds of gallons of oil. Or are people just happy turning the oil over whenever and just dealing with leaks and breakdowns that happen when their oil gets dirty?