The last enters into the composition of some of the solid lubricating greases, and is also used as an adulterant of other oils.
The viscosity test, although of considerable importance in the examination of lubricating oils, has been shown to have very little discriminative value as a general test.
This was soon put into operation in Scotland, first with the Boghead coal or Torbanehill mineral, and later with bituminous shales, and though he had to face much litigation Young successfully employed it in the manufacture of naphtha and lubricating oils, and subsequently of illuminating oils and paraffin wax, until in 1866, after the patent had expired, he transferred his works to a limited company.
Even if the slide itself is mechanically perfect, the irregularity in the thickness of the lubricating oil between the bearing surfaces of the slide is apt to produce a variable error.
For the next ten years, however, there was a decrease, and in 1908 the output had fallen to 10,858,797 barrels, of which 6,748,676 barrels (valued at $6,861,885) was obtained in the Lima district, 4,109,935 barrels (valued at $7,315,667) from the southeast district, and 186 barrels (valued at $950), suitable for lubricating purposes, from the Mecca-Belden district in Trumbull and Lorain counties.
The " cracking " process, whereby a considerable quantity of the oil which is intermediate between kerosene and lubricating oil is converted into hydrocarbons of lower specific gravity and boiling-point suitable for illuminating purposes, is one of great scientific and technical interest.
In the earlier stages of the development of the manufacture of mineral lubricating oils, the residues were distilled in cast-iron stills, and the lubricating properties of the products thus obtained were injured by overheating.
The process of distillation of lubricating oils under reduced atmospheric pressure is now in very general use, especially for obtaining the heavier products.
In the testing of mineral lubricating oils the viscosity, flash-point, cold-test," and specific gravity are the characters of chief importance.
The emulsionizing power, the To a property of penetrating oily fabrics, and lubricating impurities so that they can be readily washed away.
These, which go down to depths of 700 to 1700 ft., yield crude naphtha, from which the petroleum or kerosene is distilled; while the heavier residue (mazut) is used as lubricating oil and for fuel, for instance in the locomotives of the Transcaspian railway.
In 1847 Lyon Playfair informed him of a spring of petroleum which had made its appearance at Ridding's Colliery at Alfreton in Derbyshire, and in the following year he began to utilize it for making both burning and lubricating oils.
Therefore all bleaching and refining processes involving other means than those enumerated can only be used for technical oils and fats, such as lubricating oils, burning oils, paint oils, soap-making oils, &c.
A few of the blubber oils, like dolphin jaw and porpoise jaw oils (used for lubricating typewriting machines), have exceedingly high saponification values ` owing to their containing volatile fatty acids with a small number of carbon atoms. Notable also are coco-nut and palm-nut oils, the saponification numbers of which vary from 240 to 260, and especially butter-fat, which has a saponification value of about 227.
In most petroleum-producing countries, however, and particularly where the product is abundant, the crude oil is fractionally distilled, so as to separate it into petroleum spirit of various grades, burning oils, gas oils, lubricating oils, and (if the crude oil yields that product) paraffin.
For the testing of the viscosity of lubricating oils the Boverton Redwood standardized viscometer is generally employed in Great Britain.
It is still customary to determine the open flash-point and firetest of lubricating oils, but the close flash-point is also usually ascertained, a modification of the Abel or Abel-Pensky apparatus, known as the Pensky-Martens, having been devised for the purpose.
In 1902 it was only 200 barrels, nearly all of which came from Litchfield, Montgomery county (where oil had been found in commercial quantities in 1886), and Washington, Tazewell county, in the west central part of the state; at this time it was used locally for lubricating purposes.
Ink forms a large item in the total expenses of this department, besides which there are: oil for lubricating, turpentine and other solvents for cleaning, paper for proofs and making-ready, &c. When the work is printed it is handed to the warehousemen, who are responsible both for unprinted and printed paper.
The operation was, however, completely revolutionized in the United States by the introduction of the " cracking process," and by the division of the distillation into two parts, one consisting in the removal of the more volatile constituents of the oil, and the other in the distillation (which is usually conducted in separate stills) of the residues from the first distillation, for the production of lubricating oils and paraffin.