June 2019

ageing as a result of temperature, humidity and dusty environments. In cold temperatures oil will begin to separate into phases. Base oil becomes waxy or forms gels. Some additives can become insoluble and others, which depend on heat- induced chemical reactions, fail to perform. In such conditions the viscosity increases, leading to start-up issues and the blockage of small lubrication channels, High temperatures accelerate the rate at which the oil reacts with oxygen. Peroxides and radicals will be produced and cause formation of acids, varnish or sludge. Sludge, composed of large agglomerations of oxidised oil, metals and other impurities, attaches to the oil circuit causing malfunctions such as clogging of filters and oil separator elements. Hot conditions encourage additive and base oil decomposition, such as polymerisation where smaller fractions of the base oil stick together, resulting in higher viscosities. At very high temperatures, thermal cracking of the oil can occur, and volatile fractions of the base oil will escape into the atmosphere. High humidity also ages oil. The rate of oxidation is accelerated by water, as it will act as a catalyst and react with base oil and specific additives. Water will attack metal components which, in turn, will also act as a catalyst. Trying to extend oil life by running equipment longer than the specified oil drain interval adds to the risks associated with oil ageing. Be guided by the equipment manufacturer Choosing the right oil is not just a matter of taking an existing lubricant off the shelf. It means tailoring the characteristics of the lubricant to the needs of the oil circuit. That could be the high-volume oil requirement of open-circuit, oil-injected machines which are subject to high humidity and dust. Equally, it can apply to the higher running hours of closed- circuit oil-free equipment subjected to greater loads. For the compressor user, each combination of equipment, application and conditions is unique. To ensure the best performance and reliability of the compressed air system, it makes sense to choose the recommended lubricant and follow the equipment manufacturer’s guidelines. on moving parts, and provide insufficient lubrication of vital features. Also, to be considered is the interaction of the oil with other equipment items. A non-genuine lubricant may degrade the sealing function and lead to corrosion of metal parts, seriously affecting the performance of the equipment. The full grim picture of oil/equipment incompatibility should encourage users to follow manufacturers’ recommendations. The wrong choice of lubricant can mean shorter lifetime or even failure for bearings and oil pumps, as they will not be lubricated according to the specification. With an oil circuit full of deposits, there will be increased internal pressure and moving parts will not work properly. Ultimately, not only can this result in increased energy consumption but, in a worst-case scenario, it poses the risk of element failure and total breakdown. Oil ageing: influence of the environment One of the most important factors in any maintenance schedule is recognition that extending oil life beyond specified oil drain intervals risks the problems associated with oil Process, Controls & Plant Focus on: Compressed Air Web: www.tcasdryair.co.uk Tel: 01952 292121 DRY AIR HIRE FIVE FIXED BUDGETING SOLUTION - DRY AIR HIRE FIVE offers a fixed monthly budgeting solution for all compressed air equipment, installation, commissioning, equipment service & breakdown support for 5 years. PEACE OF MIND - Brand new, reliable and energy efficient HPC compressed air equipment including all service, breakdown and support for five years. No Hidden Costs, No restrictions, No previous claim penalties. NO CAPITAL PURCHASE - DRY AIR HIRE FIVE requires no capital purchase. FLEXIBILITY - Demand for compressed air can often increase as your company grows. With DRY AIR HIRE FIVE, should this happen, we will grow with you. NO QUIBBLE WARRANTY - We offer as part of the DRY AIR HIRE FIVE agreement total peace of mind for 5 years. DRY AIR HIRE FIVE offers a viable alternative to compressed air equipment purchase with added benefits over a five year period. Industrial compressed air is often regarded as the ‘fourth utility’ and therefore the demand for ultimate reliability & optimum efficiency is the number one priority. DRY AIR HIRE FIVE offers these benefits which are outlined below...