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Wear can be minimised by good lubrication. We have travelled far since lubrication meant just “oil”; refining processes have improved, oils are more “oily”, and additives reduce the effects of gums, oxidation, acid formation, etc., over a useful service life. Extreme pressure agents and detergents allow operation under conditions of load and temperature not possible with straight oils. Yet all these advances count for little, unless abrasives are excluded.

The effectiveness of an oil filter and of the method in which it is employed is judged by the level of lubricating quality it maintains in the bearings and other sliding parts of the engine. The word “quality” here includes freedom from dirt (particularly from those dirt particles which, by their size and composition, are likely to cause abrasive wear) and the presence in sufficient quantity of those additives which the modern refiner incorporates in Heavy Duty oils to reduce oxidation, piston‐ring sticking and other ills.

THE ROLLING of bright metal sheet strip and foil requires that the highly finished rolls should be lubricated. Originally a drip feed was used, just sufficient to maintain an oil film, but as the output required from mills rolling at high speeds has increased there has been an almost universal adoption of flood cooling by means of a light mineral oil with additives. These additives are usually natural fatty substances like lanoline, vegetable or coconut oil or chemical additives in the form of complex higher alcohols. The additives are chosen largely according to the advice of oil suppliers and are usually compounded with the oil before purchase but occasionally may be blended to the preference of the mill manager as a result of his own experience. In many cases the exact mixture is regarded as a trade secret, a situation which may complicate the problems of filtration.

BEFORE the war scientific filtration as applied to aircraft was a little known subject. The prime concern of the people developing aircraft in those days was the attainment of higher power output, ceiling and maximum speed. More streamlining was the cry and, although filters were available, they were rarely used.

There are still a great many people, unfortunately a number of them are engineers, who regard lubrication merely as “oil”, a necessary evil that must be dispensed by the “greaser” with his oil can or by the car owner who has heard it said that his engine will not run without it. Fortunately, most engineers and many other people, are becoming more lubrication minded and are realising that correct lubrication is a science and when correctly applied can save them a lot of money by reducing breakdowns and thus increasing production.

RICHARDSON, writing in Scientific Lubrication recently, stressed the need for strict attention to the cleanliness of the fluids used in hydraulically operated automatic transmissions with special reference to storage conditions, cleaning materials and the care of filters. In the same number of the journal Chisholm briefly described methods of oil filtration in general when discussing the maintenance of industrial hydraulic systems. It will be found too that the majority of articles and booklets dealing with hydraulic fluids and systems—industrial, automotive and aeronautic—pay attention to the potential effect of impurities, their exclusion and removal, in greater or lesser detail. Similarly diagrams of typical hydraulic circuits will usually show permanent wire mesh screens or strainers in the oil reservoir on the suction side of the pump and sometimes below the filler plug while by‐pass filters are generally located at some point in the circuit after the pump. (By‐pass filters owe their popularity to the fact that should the element become completely clogged the flow of hydraulic oil is not thereby interrupted).

Almost all internal combustion engines used for road transport, and almost every stationery internal combustion engine is fitted with a lubricating oil filter. Up to now, there is no standard test for assessing the performance of any oil filter. The Motor Industry Research Association have been examining oil filter test methods with a view to putting forward a test that might find general acceptance. The following is abridged from M.I.R.A., Report No. 1948/7. “An Examination of Various Methods of Testing Partial Flow Oil Filters for Motor Vehicle Engines” by L. Rosenfield.

A NEW Turbine Oil Filter was demonstrated to A visitors and members of the technical press recently at the works of Stream‐Line Filters Ltd., Henley Park, Normandy, Nr. Guildford. The well‐known Stream‐Line edge type filter has been used on marine diesel engines for more than 30 years and a very early development was a plant for the treatment of insulating oil. These plants remove virtually all the solids and certainly all the fibrous materials, as well as reducing the water content to below 10 parts per million. This plant provides for the heating of the oil, followed by its filtration, followed by a vacuum treatment which boils off the moisture. Stream‐Line are supplying such plants at the rate of about 300 per annum for oil flow rates from 5 to 1,750 gal/hr.

SOME THREE YEARS or so ago a statistical study of the British motor car population revealed that the average life of the individual vehicle was significantly longer than pre‐war. Several contributory factors were discussed. Firstly we apparently drive fewer miles a year than heretofore while the quality of engines and components such as tyres is much higher nowadays. We also note in the post‐war period that changes in vehicle design and greater mechanical efficiency have reduced the time spent on maintenance and at the same time made driving easier. Included here are long‐life plugs, ‘permanent’ anti‐freeze solutions, anti‐corrosive underseal, improved suspension and joints ‘packed‐for‐life’ with special quality grease. All these things might he regarded as indicative of a compensatory trend; as we drive less in our improved labour‐saving vehicles, road conditions become more uncomfortable and hazardous.

THE Engineering, Marine, Welding and Nuclear Energy Exhibition opens at Olympia on April 16th and runs until April 30. It is open from 10 a.m. to 6 p.m. each day (except Sundays), with the exception of April 27th, 28th, and 29th, when it remains open until 8 p.m. Price of admission is 3s. There are well over 500 stands and of these between 60 and 70 are showing products that should be of interest to most readers of Scientific Lubrication, since they concern some type of lubrication equipment. Amongst these are the following, and the illustrations reproduced here concern items which will be exhibited on the stands. Items in bold type describe new products or products being exhibited for the first time.