USBN October 2017

10 US BUSINESS NEWS / OCTOBER 2017 , The by-products of oxidation, are acids that attack the various types of flexible seals, used in the hydraulic system. These include the organic materials like rubber, found in the mufflers and the O rings in main control valves. This exposure causes synthetic and rubber seals in the system to lose their flexibility and become brittle. It also creates rust on metal components in the system. Worse yet, the sludges produced as a by-product and overheating acts as insulation, thereby reducing the heat dissipation of the reservoir holding tank. The contamination also causes micro pitting of milled and polished metal surfaces by corrosion of the pump and valve components. This results in a reduction of the lubricating properties of the oil, when degradation is not detected and properly managed. Sludge occurring in the hydraulic system will hold water suspended in the oil, also as mentioned, it becomes an accelerator in the degradation process. This water is not observable as free water in the system, it is dissolved and a colloidal suspension of H2O within the oil itself. A side effect of water in the oil, it reveals itself as a ride quality issue ex. ‘sponginess’, or bouncing of the car can be observed by passengers of a hydraulic elevator. Now we have identified rubber particles, acid, rust, varnish and other contamination along with water and oxygen suspended in the hydraulic oil. How often do these contamination issues result in frequent levelling and operational problems? How often is blame placed on the operating valve as the cause of the problem? The contractor replaces the valve, or spends repeated time on call backs trying to adjust the valve, unaware the real cause is the contaminated oil varnish and particulate matter found in the valve body? Finally, and not to be forgotten, what about the cylinder packing replacements and flooded oil in the pits? Now that we know all of this, what can we do? What is the point? As technicians, not scientists, we are willing to postulate that the hydraulic system components of an elevator, if properly maintained, monitored and serviced, with an operating temperature of say 95 degrees and motor protection, should operate reliably for 30-50 years with no major components needing replacement. That’s not to say an upgraded improved controller can’t be added. Here we are talking about the ‘bones’ of the elevator, the hydraulic system. Oil management A good hydraulic oil testing and reclamation programme can make the equipment last longer and perform more efficiently. This in turn will help control the maintenance contractor’s labour and parts overhead, as well as their profit margin while maintaining the equipment properly. For the record, let’s begin to think of the MCP as ‘asset management’, rather than the misnomer a preventive maintenance programme. The result can be a successful service programme. Not just a win for the service contractor, it can be a win for the owner too. If a typical hydraulic elevator installed today, we might replace the controller and minor components in say 15-25 years. The pump motor when protected with an electronic soft starter, should also last for 15-25 years without a major incident or longer, depending on usage. The hydraulic elevator system, when properly serviced and oil preserved, should theoretically remain intact except for minor repairs. The main hydraulic control valve when kept clean filtered uncontaminated oil, should be able to withstand 25 years and countless cycles of use. This reliability, combined with in ground hydraulic cylinders enclosed in a protective PVC sleeve and is therefore isolated from corrosion and electrolysis, oxidation and ground water contamination. The hydraulic system can provide reliable service well beyond 25 years. We might go further and ask, just how long would a hydraulic elevator last if the door system hardware is also properly maintained and repaired, along with the system and controller? 25-50, or maybe 75 years? Why not? Considering regular systematic visits by a technician in a managed asset protection plan and MCP, the service contractor should be able to calculate a predictable component failure rate and scheduled replacement plans, that reduces exposure to the uncertainty of faulty operation and subsequent litigation costs. Improved reliability and predictability will also provide more consistent and predictable profit margins. In short, a lifetime service programme should be mutually successful for both the buyer and seller. Conclusion In summary, an aggressive oil testing and reclamation programme for hydraulic elevators refurbishment is destined to become the industry standard, within the near future. The factors as presented here and combined with elevating the contractor’s reputation makes it an attractive methodology. The service price and profit motive of this technology in the elevator industry will become more accepted, as industry education and trade acceptance takes place. Energy savings and minimal space requirements are often the driving point for purchase of a traction elevator. These are often considered, but miss being properly compared with the initial construction prices and continuing service programme costs, that should be factored into the equation. The overall financial benefit of the hydraulic elevator can add up to a significant amount, over the long term, for all involved. The demise of the hydraulic elevator has been greatly exaggerated! In the long run, the hydraulic elevator is here to stay!