Lubricant, wrong

Customer supplied products that are issued for incorporation into supplies don t often require maintenance however, items for use in conjunction with the contract may be retained for such a duration that maintenance is necessary. If the products require any maintenance you should be provided with a maintenance specification and the appropriate equipment to do the job. Maintenance may include both preventive and corrective maintenance but you should clarify with your customer which it is. You may have the means for preventive maintenance, such as lubrication and calibration, but not for repairs. Always establish your obligations in the contract regarding customer supplied product, because you could take on commitments for which you are not contractually covered if something should go wrong. You need to establish who will supply the spares and re-certify the equipment following repair. 

Incorrect lubrication can take many forms. One example is the use of oil that is too thick or too thin, or is incompatible with the metal of the gears. Others include unsuitable methods of application, bad filtration, inadequate maintenance, filling to the wrong level, and poor standards of storage and handling. 

The performance of lubricants can be significantly improved by the use of additives, which can make up from ppm to 30%, (w/w) of the lubricant. Typical values of total additive content are in the order of 5%. Often different additives are combined to improve several properties. Choosing the right combination can have synergistic effects on the overall performance, but a wrong choice can render some of them inactive. An important issue with additives can be the compatibility of the additives with the solid surfaces or with polymer or rubber seals. In table 11.1 the most important types of additives are listed. The list also illustrates the main practical problems encountered when making lubricants. 

Super tractor universal oils (STUOs), widely used in Europe and some other areas, are the extreme of multi-purpose lubricants. They arise from tractor hydraulic oils used for various hydraulic applications of agricultural machinery with added lubricant properties. STUOs have considerable advantages in reducing the number of oils required on a farm and reduce the possibility of wrong fluids in wrong reservoirs or machinery. Bulk purchases of one oil reduce unit costs against the costs of purchasing multiple hydraulic oils and lubricants. 

In 1929 E. W. Dean and G. H. B. Davis,4 of Standard Oil, used this representation for viscosities to develop the VI concept for lubricant feedstocks, intermediates, and base stocks. In modified form, this method for describing the viscosity-temperature relationship for base stocks and lubricants has become one of the bedrocks of the industry. The VI of a base stock now immediately brings to mind, rightly or wrongly, other features of interest to lubricants professionals, for example, oxidation stability and chemical composition (e.g., content of isoparaffins and cycloparaffins), and more recently, volatility. It is, however, best to regard this method as a means to express the rheological properties (the science of flow) of a base stock and use other more specific tests to measure other properties. 

Manufacturers report that in 99 out of every 100 service calls for plug valves, the only thing that was wrong was that the valve needed lubrication. 

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