Who Owns the Dirt?
October 6 IN Oil Scrubber
Who Owns the Dirt?


“Who Owns the Dirt?” is a silly question, but the answer may determine the life expectancy of the hydraulic elevator equipment.

The hydraulic oil is the lifeblood of the hydraulic system; contaminated or dirty oil can be responsible for up to 80% of the failures in an oil system. The symptoms of oil contamination are typically treated as maintenance problems, because only the symptoms are addressed in the maintenance contract. Oil contamination is typically not addressed in the contract.

The hydraulic oil in a hydraulic elevator is often an afterthought.  Building often owners assume that the oil is just another part of the elevator, just like the piston or valve.

Addressing who owns the dirt in the oil is a win/win for both the Building Owner and the Service Company.  If we can determine who owns the dirt, contamination will be addressed and oil related failures can be prevented.

The Building Owner owns the hydraulic oil, just as they own carpet on the floors and the paint on the walls. The hydraulic oil gets dirty in the same way as the carpets and walls.

Building owners pay to clean the carpets, because clean carpets do not wear out as fast as dirty carpets; the same goes for the hydraulic oil.  The janitorial staff or a contractor is paid to remove the dirt from the carpets; it is not assumed that the carpets will be cleaned for free.

When it comes to the dirt in the carpets, it is in the contract, so there is an agreement of who is paid to remove it; this is not always the case when it comes to the dirt in the hydraulic oil.

Addressing who owns the dirt in the contract assures that the carpets are cleaned and last longer.  The building owner benefits from extended life from their investment in flooring and the service company benefits by providing a needed service, which they are fairly compensated for.  Why is that different for the hydraulic oil?

The cost of an outage of the hydraulic elevator can be substantially higher than the aesthetic and replacement values of clean carpets.  A method for quantifying the benefit of cleaning the oil is available.

Noria Corporation developed Life Extension Models for hydraulic oils.  This model demonstrates the importance of keeping the oil clean and the benefit of maintaining the hydraulic oil.

In this model, improving the ISO Cleanliness Code, by cleaning the oil, results in a life extension for the oil and hydraulic components.  For example, if the ISO Cleanliness Code is improved from a 21/19/16 to 16/14/11 this represents a 4X life extension for the oil and hydraulic components.


The profit motive ensures that attention will be paid to the oil. The building owner benefits from fewer breakdowns and extended equipment life and the Service Company is paid for performing a beneficial service.  If responsibility for the oil is not established, the oil will be ignored, resulting in frequent breakdowns and diminished equipment life.


Once we agree who owns the dirt, we can address the root cause of hydraulic failures and extend the life of the oil and hydraulic components.