USBN October 2017

8 US BUSINESS NEWS / OCTOBER 2017 , includes the details for each service task to be performed. The programmes are available for both owner and contractor. Points to ponder How much more effective could a technician be, when servicing accounts with fewer call back interruptions? How much better quality effort could be delivered to the customer, when a service visit takes place? How would the public perception of the service contractor be with their fleet of elevators operating efficiently and without noise, levelling and reliability issues? How predictable would the replacement of the parts be? Accurate predictions would result in more efficient and reliable uptime. Would reliability command a premium service price in most hydraulic and traction markets? The MCP programme can produce a higher level of customer satisfaction. The contractors that are looking for 10, 20 years plus, or ‘lifetime’ contracts can realistically offer this custom service programme, to premium clients. New ideas for hydraulic elevators When we get to hydraulic elevators; there is one service method technology the industry is beginning to find acceptance in. This is the preservation of hydraulic oil in elevator systems, by using periodic oil testing, analysis and filtration. What we must understand is the ageing and degradation of hydraulic oil creates havoc within the such a system. Managing and controlling the quality of the oil, brings under control several variables affecting the total hydraulic cost equation. The greatest consumer of oil was the internal combustion engine and where most of the conservation efforts were concentrated. The efforts resulted in a significant savings of oil, along with the added benefit of cleaner air for the environment. After the oil industry and science addressed the automotive industry, more challenging applications were then confronted. The aviation, marine, industrial, power transmission and turbine industries were subjected to close analysis. One by one, the standards and usage for each industry were examined and refined. When looking at the common oil usage in all the above applications, we arrive at some basic understanding and functions of oil: • Lubrication – Reduction of friction in moving parts, thereby extending the life of those parts; • Transfer of heat – Keeping moving parts cool; • Transmitting force – Such as used in a hydraulic system for power assisted mechanical equipment; • Providing dielectric strength – Normally used in electric power transmission equipment and; • Preventing corrosion – example: Cleaning and oiling weapons during military service. A reduction in the volume of oil in a system has minimal effect on these except for nos. 2, transfer of heat and 3, transmitting force. Since the early 1960’s most of transportation, industrial, marine, aviation, power transmission and turbine equipment has the benefit of operating with more efficient engineering of hydraulic system designs, employing less oil and higher pressures. To keep equipment operating efficiently and protect capital investment, industry related owners and managers were compelled to improve the quality of maintenance programmes. Oil testing and analysis programmes were developed, to determine the relationship of wear on the equipment and degradation of the oil. The research and results revealed that oil really does not wear out. It oxidizes and becomes contaminated with impurities and creates organic compounds, namely acids and sludge material. The acids formed are most commonly acetic, formic and other long chain acids. This contamination in the oil attacks the interior workings of the hydraulic system. The sludge formed reduces the heat dissipation properties of the system and further accelerates the acidic reaction within the oil. When the impurities and oxidation by products are examined, an estimate of the degradation of the subject system can be developed. Additionally, oil analysis can be used to identify the system component, degradation and other wear from the oil contamination taking place. Those impurities in the system can be filtered and removed, spent additives and oxidation inhibitors reintroduced and voila! A new batch of is oil ready to load for another life cycle and importantly, the testing results provide a baseline diagnosis of the health of the equipment, for future reference. The elevator industry Oil testing technology has finally arrived at the elevator trade. In this conservative industry technology lags by 10-15 years behind other industries. Given the reliability required to keep the riding public safe, new technologies are only introduced when thoroughly studied and considered safe. Elevator manufacturers now design equipment with high operating pressures and reduced quantities of oil in hydraulic power units, to control cost and space. The result of these designs is the hydraulic system must work harder at removing heat, transmitting force and lubricating the components in the system. With all three of those factors noted; the hydraulic systems are frequently showing signs of premature oil ageing, contamination and degradation. One manufacturer produced a chart with the operating range for their power unit not to exceed 158 degrees Fahrenheit. This is the upper range of satisfactory oil temperatures. The operating temperature of oil is critical in this equation. The main catalyst that starts the process and speeds the ageing process in hydraulic oil is the elevated operating temperature. Another key ingredient in the mix, is moisture from atmospheric condensation. Moisture is not only an accelerant in the ageing process, it can by itself compound the problems in the elevator. However, nothing creates deterioration of hydraulic oil faster than oxygen combined with excessive heat in the system. Exactly as found in other types of equipment noted above the acids and sludges Over time, hydraulic oil will mix with oxygen in the atmosphere and begin to form organic acids in the oil. In electrical power transmission equipment, the oxygen degradation process is delayed by pressurising the tanks with a blanket of dry nitrogen gas, this inert gas is suspended on the top of the oil. Elevator oil reservoirs are not pressure sealed and allow air with oxygen to freely mix over time, with the hydraulic oil in the reservoir. This mixture causes the oxidation process to occur.