Document NrQNNXg2RL8knaLLd77b3VRR

STLCOPCB4060076 When the pressure's really on TEXACO RANDO OIL HD cuts out the wear and tear Hydraulic systems take a beating at pressures above 1500 psi--unless they're protected by a high anti-wear hydraulic oil. Texaco Rando Oil HD has the special anti-wear characteris tics that mean longer life for pumps and valves in high pressure, high speed systems. Rando HD gives you smoother performance, uniform pressure and a clean system, for fewer oxidation foul-ups, less downtime -- less maintenance. And Rando HD resists foaming, separates readily from water, and prevents rust through out the hydraulic system. For a fact filled Rando Oil leaflet showing typical test results, write: Texaco Inc., 135 East 42nd Street, New York, N. Y. 10017. TEXACO IDEAS KEEP THINGS MOVING DSW 202010 STLCOPCB4060077 LUBRICATION A TECHNICAL PUBLICATION DEVOTED TO THE SELECTION AND USE OF LUBRICANTS Published by Texaco Inc., 135 East 42nd Street, New York, N. Y. 10017 J. H. Rambin, Jr., Chairman of the Board of Directors; J. W. Foley, Vice Chairman of the Board of Directors; M. J. Bpley, Jr., President; A. W. Baucum, Harvey Cash, J. W. Green, J. H. Pipkin, Executive Vice Presidents; W. E. Avery, A. M. Card, W. G. Copeland, S. T. Crossland, R. J. Derby, C. H. Dodson, Henry Flynn, M. F. Granville, Ben Halsell, O. B. Hocker, H. C. Hose, L. C. Kemp, Jr., Kerryn King, J. W. Kinnear, J. I. Mingay, W. H. Ryer, H. O. Woodruff, Vice Presidents; A. B. Steed, Vice President and General Counsel; W. J. Clayton, Secretary; W. R. Love, Comptroller; E. C. Mitchell, Treasurer. Volume 52, Number 9,1966 COPYRIGHTS: The contents of LUBRICATION are copyrighted and cannot be reprinted legally by other publications without written prior approval from Texaco and then only if the article is quoted exactly and accompanied by the credit line "Courtesy of Texaco's magazine LUBRICATION", Copyright 1966 by Texaco Inc. Copyright under International Copyright Convention. All rights Reserved under PanAmerican Copyright Convention. CHANGE OF ADDRESS: In reporting change of address please give both old and new address: Write to--C. R. Frohlin, Texaco Inc. 135 E. 42nd St., New York, N. Y. 1O017: or H. E. Whiting, Texaco Canada Ltd., 1425 Mountain St., Montreal 25, Quebec, Canada. CONTAMINANT REMOVAL FROM CIRCULATING OIL SYSTEMS-II he preceding issue of this publication dis (3) The full-flow connection as used with filters Tcussed sources of contamination in circulating is identical with the shunt hook-up. The basic dif oil systems and equipment for its control and ference between the two methods is that the full removal, including gravity separation, centrifugfelosw filter system must contain sufficient cartridges and filters. This issue will conclude the article by dis to permit all of the oil entering the filter to pass cussing applications of various purification systems. through the cartridges without by-passing through the relief valves. FLOW SYSTEMS (4) The combination system normally requires Five commonly used methods of filter installation are by-pass, shunt, full-flow, combination, and inde pendent. A brief description of each follows; (1) The by-pass method, perhaps the most com mon, operates on only a portion of the oil in the system and takes its supply off the main lubricant line, usually between the discharge pump and the oil cooler. The amount by-passed is normally only approximately 10% of the quantity of oil circu lated by the oil pump and is generally returned to the sump. By this arrangement, the lubricated area is never supplied with completely purified oil. (2) The shunt connection as used with cartridge filters directs the flow of oil from the oil pump two units, one returning directly to the sump and the other handling the full flow to the bearings. The combination principle is applied to centrifugal sep aration as well as to filtration. A "hydraulic cy clone"* is used as an unblockable full-flow coarse separator, preventing any isolated coarse particles from circulating to the bearings, while a centrifuge is used in by-pass operation. Figure 20 is a sche matic diagram of a combination system. (5) The independent system makes use of a separate auxiliary pump completely separate from the lubricating system. Here a portion of the system oil is pumped through the filter or purifier and then returned directly to the sump or crankcase. through the filter. Shunt type filters are equipped with relief valves. The entire flow of oil at first goes INTERNAL COMBUSTION ENGINES through the cartridges, but as the cartridges become The oil filter or purifier is second only to the air loaded with contaminants, the flow of oil is divided. cleaner in importance as auxiliary equipment for A portion of the oil continues to pass through the cartridge and the balance by-passes. * The "hydraulic cyclone", although not a centrifuge, separates heavy particles from a liquid stream in swirling flow. [125] DSW 202011 STLCOPCB4060078 LUBRICATION -\ Figure 20 -- A schematic diagram of a combination flow sys tem using a "hydraulic cyclone" in full-flow and a centrifuge in by-pass. internal combustion engines. Oil cleanliness has a direct correlation with engine wear, operating and maintenance costs, out-of-operation time, length of time between overhauls, etc. Equipment manufac turers and users are aware that efficient oil condi tioning equipment results in a substantial reduction in overall costs. This is understandable when one considers that virtually every known type of con taminant can be detected in used internal combus tion engine oils. Aside from engine wear, contami nants of both internal and external origin also con tribute to bearing corrosion, oil line plugging, oil starvation, stuck valves and hydraulic valve lifters, ring sticking, oil ring plugging and other condi tions of engine malfunctioning. The need to mini mize these problems has been a significant factor in the development and acceptance of inhibited, highly dispersant oil. Although a wide variety of filters and oil purifiers are used in stationary service, the space limitations of the on-the-road units generally require the use of relatively small filter cartridges. There is also a definite trend towards the incorporation of full-flow design. Units are available to provide full-flow filtered oils to critical areas with shunt or by-pass filtered oils to less critical areas. Automotive Gasoline Engines Space limitations in gasoline engines necessitate the use of relatively small replaceable cartridge fil ters, and the widespread use of heavy duty dispers ant type oils restricts the use of highly adsorbent types. Wide use is made of folded, impregnated paper, extended area type cartridges as well as waste packed depth type cartridges. In addition, a filter screen at the oil pump intake is standard equipment. The four systems -- by-pass, shunt, full flow and combination as applied to automotive crankcase oil filtration are illustrated schematically in Figures 21. 22, 23, 24, and 25. ' Although the trend is towards full-flow oil filtra tion, the majority of passenger cars are installed with by-pass or shunt systems. Some cars are equipped with a full-flow filter in the oil supply line to the hydraulic valve lifters where the cleanest oil is required. The remainder of the system works on partially filtered by-pass oil. Although maintenance procedures vary greatly, the generally accepted practice is to replace filters or filter cartridges every 6000 to 7000 miles, except in cars equipped with hydraulic valve lifters where the prescribed practice is 5000-mile filter changes. However, one manufacturer recommends a filter change with each oil change. Results of 5,000 miles of road testing on 25 auto mobiles are charted in Figure 26. The 100 percent wear indicated is considered to be the amount of wear obtained without oil filters of any type. Results represent those obtained under average driving con ditions encountered in all parts of the country using all types of fuel and all types of lubricating oil. Automotive Diesel Engines Similar to gasoline engines, space limitations re strict the size and type of filter used with highway type diesel engines. The use of additive oils in this service dictates the preference for absorbent depth type and extended area surface type filters. Adsorb ent type filters are not generally used, as additive depletion may result. Any of the gasoline engine filter systems shown in Figures 21, 22, 23, 24, and 25 are applicable to diesel engines as well. The by-pass system is widely used. The combination system using separate car tridges for by-pass and for full flow filtration is in common use in heavy duty applications, where the space limitations are not too restrictive. Figure 27 illustrates a typical example of such a combination system for automotive diesel engines. The full flow portion of the combination is intended to maintain a copious flow of oil while removing mainly the larger contaminant particles; the by-pass portion removes the finer contaminant particles. Because of the relatively large fuel soot contamination in diesel engines and the common use of dispersant oils, the proper selection of an efficient filter is of consider able importance in maintenance. Filtration has also received considerable attention recently in railway diesel engines, particularly with the introduction of high dispersant oils for locomo tive service. Highly efficient pleated paper filters [126] DSW 202012 STLCOPCB4060079 LUBRICATION Figure 21 -- A schematic of a by-pass type automotive filter system. Figure 22 -- A schematic of a shunt type automotive filter system. system. OIL COOLER Courtesy of Fram Corporation Figure 25 -- A schematic of a combination full flow and by-pass automotive filter system. have proven very satisfactory when used in com bination with the new type railway diesel oils.10 Stationary Industrial Engines In industrial service, where space limitation may not be as important a factor, a number of satisfac tory oil conditioning systems can be employed. In addition to the variety of equipment used for indi vidual engines for full-flow, continuous or by-pass operation, portable purifiers and filters are often used to service several engines. Figure 28 illustrates typical dry sump (a variation Figure 24 -- Details of a two stage full flow depth type auto motive filter incorporating fine and coarse sections in parallel. of the shunt system), by-pass and full flow filter systems for large engines in stationary service. With non-additive oils, adsorbent type depth filters are used quite advantageously, since they remove extra neous contaminants and oxidation products as well. Complete preassembled centrifuge systems are avail able for contaminant removal, such as a combina tion centrifuge with a filter and a centrifuge com plete with automatic wash water density controls. Examples of these two types are shown in Figures 29 and 30. Diesel engines probably present the greatest chal lenge of engine oil purification, as diesels tend to contaminate the crankcase oil to a greater extent [127] DSVM 202013 LUBRICATION than other engines. For example, under unfavorable operating conditions, it is not unusual to accumulate 0.3 pounds of debris per 1,000 rated horsepower hours. In fact, analysis has shown that a 1,000 horse power diesel engine may, in a year's service, dis card through the oil purifier: 110 gallons of water, 530 pounds of carbon (fuel soot), 180 pounds of oxidized matter, and 150 pounds of minerals (dust, iron, lead, copper, tin, etc.). Heavy duty oils can be used satisfactorily in diesel engines equipped with centrifuges. However, these oils tend to form stable emulsions with water, thus making the removal of water by centrifuging diffi cult. If stable emulsions persist, it may be helpful to heat the oil to approximately 180F. before it enters the centrifuge to encourage the emulsions to break. Although a certain amount of water in the crankcase from blow-by of combustion products and conden sation is inevitable, water washing should be limited to straight mineral oils. As far as diesel engine serv ice is concerned, these oils are generally restricted to large, slow speed diesel engine crankcase lubrica tion. STEAM TURBINES Oil conditioning equipment is highly important in the preparation of new steam turbine lubricating systems, in flushing of reconditioned systems, and in the maintenance of lubricating oil during operation. Water, rust, dirt and wear particles are the principal contaminants in steam turbine lubricating oil sys tems. Premium quality turbine oils are formulated to provide top performance and system protection, even in the presence of some contamination. They are generally defined as highly refined oils with good water separating characteristics incorporating anti foam, anti-rust and anti-oxidation additives. In com bination with effective purification, these oils are serving the requirements of the steam turbine sys tems in a remarkably efficient fashion. Relatively simple maintenance programs providing for oil conditioning equipment will preserve these essen tial qualities and provide dependable service for ex tended periods. The use of oils containing additives precludes the use of adsorbent type filter materials, although other purification systems can be used satisfactorily. Water contamination is probably the greatest single concern in steam turbines. In addition to the problems of sludge formation and oil emulsification, excessive water may eventually cause depletion of the rust inhibitor and without it, serious rusting can occur. Rusting, especially in critical areas such as governors, actuators, etc., cannot be tolerated. [128] DS\N 22014 STLCOPCB4060081 LUBRICATION (3) Filter systems. The filters are limited to sur face and absorbent types, except where straight mineral oils are employed. One variation is to com bine gravity settling in series with gravity fed open bag filters, followed by a pressure fed polishing filter, such as shown schematically in Figure 32. A polishing filter serves to remove the majority of the very finely divided contaminant particles and mois ture haze. It is particularly important that the oil purifica tion equipment be operated continuously during the installation of new turbine systems and recondition ing of existing systems. This ensures removal of potentially harmful materials which may be present in such systems before they can circulate and cause damage. In fact, a Joint ASTM-ASME Committee on Turbine Lubrication has issued a list of recom mended practices for preparing newly installed turbine systems, cleaning used systems and purify ing turbine oils.11'12 HYDRAULIC SYSTEMS Figure 27 -- A schematic of a combination full flow and by pass filtration system for highway type diesel engines. Entrance of water may be: (1) From steam leaks due to faulty shaft packig glands or seals; (2) Through leaks in cooling coils (leakage of sea water on marine units is especially serious); (3) Condensation from moisture in the air; (4) Higher than normal gland water tempera tures, and (5) Steam blow-by when glands become scaled or when vacuum is lost. The use of dehumidifiers on tank breathers is helpful in reducing moisture contamination from condensation. In addition, the following auxiliary oil purification equipment may be used effectively in maintaining turbine oil quality: (I) Gravity settlers for separation of excess water and suspended insoluble oxidized material, dirt, etc. Settling purification is normally conducted by heating the oil to approximately 120 to 140 F. and permitting the oil to stand for several days. (2 ) Centrifuges for faster and more effective re moval of contaminants. Centrifuges are generally connected to the sump for intermittent or continu ous processing of the oil. The oil is supplied to the centrifuge by an auxiliary pump. Wet centrifuging for removal of oil soluble oxidation products is gen erally restricted to straight mineral oils or turbine oils containing rust and oxidation inhibitors which resist depletion by water washing. The centrifuge is used extensively in the circulating oil systems of steam turbines used for marine propulsion. A typi cal system of this type is shown in Figure 31. Oil cleanliness is of paramount importance in hydraulic systems113>1'M5'1` The same type of oils used in steam turbine systems are also generally used as premium grade hydraulic oils. As previously de fined, these are highly refined, inhibited oils with good water separating characteristics. The fact that they are usually inhibited precludes the use of ad sorbent (active) type filters. However, in those few FtLTEX riO. '*30A : - Sc*VfYQir*G PUMP DRY SUMP SYSTEM . atstQvoiP W-'<iNTPRCSSURt OIL FILTER ' uccfc tasK * 2 pump3 ' .TlPtOOU ( ` C VJ P/SCHAP6C TO 8CAP1MGS BY PASS SYSTEM FULL FLOW SYSTEM Courtesy of Wm. W. Nugent & Co. (Inc.) Figure 28 -- Some typical filtration systems for stationary internal combustion engines. [129] DSW 202015 STLCOPCB4060082 LUBRICATION "V Courtesy of The DeLaval Separator Company Figure 29 -- A combination centrifuge and filter. systems employing straight mineral oils, active filters can be used. Other purification equipment described under Steam Turbines is also applicable to hydraulic systems. Under normal conditions, the quantity of con taminants entering a closed and sealed hydraulic sys tem will be small. However, when one considers the possible damage to precision valves or pumps that may result from the presence of contaminants, it can be realized that the use of oil purification equip ment is highly desirable. Courtesy of Sharpies Equipment Division, Pennsalt Chemicals Corporation Figure 30 -- A centrifuge with automatic wash water density control. The type of purification equipment will depend upon the type and amount of contaminant. In large systems where water contamination may be rela tively heavy, gravity settling tanks for batch purifi cation or centrifuges for either continuous or inter mittent purification can be considered. Smaller sys tems can be satisfactorily serviced by absorbent or [130] dS\N 202016 STLCOPCB4060083 LUBRICATION Courtesy of Wm. W. Nugent & Co. (Inc.) Figure 32 -- A schematic of a typical oil filtration system for stationary steam turbines. surface filters. Where a number of units are operat ing, a portable conditioner can be employed and operated on shunt connection to the various indi vidual unit sumps. ROLLING MILLS Contamination of heavy circulating oils is a major problem in rolling mills. The main contaminants are water, mill scale, and dirt. The mill scale and dirt are not only abrasive, but also stabilize emulsions which form from mixing lubricating oil with water, "he object, then, is to maintain the circulating oil as free of these contaminants as possible. The large quantities of oil and the high degree of contamina tion encountered in rolling mills often requires the use of both continuous and batch purification. The fact that water contamination is a problem in roll ing mills dictates the use of circulating oils with good water separating characteristics. However, in adequate purification eventually encourages the formation of stable emulsions and sludge which makes subsequent recovery more difficult. The elaborate oil conditioning systems employed in rolling mills generally consist of several gravity settling tanks for batch removal of bulk contami nants and polishing cartridges or bag filters with magnetic strainers for removal of small mill scale particles. Compact combination unit purifiers are popular for the. polishing step and combine a water or sludge precipitation compartment with a series of cloth bag filters stretched over wire frames, as described earlier in this article. Metal gauze bags are also used in combination units with automatic cleaning. Where continuous gravity settling is desired, as in cold strip mills, the system is equipped with a baffled settling tank and a storage supply tank. The baffles are arranged on the oil inlet side of the settler to permit slow movement of oil and efficient separation of the water and debris, which settles to the bottom and is easily removed. The separated oil overflows the baffles to the clean oil compartment where it is drawn off continuously, finished by a centrifuge or filter, and finally returned to the oil supply tank. Filters especially adapted to this serv ice are available, and are capable of removing for eign particles down to a few microns in size. Belt type surface filters of the flat bed pressure variety are often used in combination with polish ing filters in both ferrous and non ferrous rolling oil systems. One system incorporates an auto matically cycling precoat filter with a belt type filter to obtain a very high degree of rolling oil contami nant removal required in the production of stainless M---------------------- FILTER CYCLE 3-WAY VALVE <----------- DESLUDGING CYCLE----------- EJECTOR .' SLURRY VACUUM BOX Courtesy of STEEL and Hydromation Engineering Company Figure 33 -- A schematic of an automatic cycling precoat filter in combination with a belt type filter system as applied to rolling thin stainless steel strip. [131] DSW 202017 STLCOPCB4060084 LUBRICATION Courtesy of The Cvno Engineering Corporation Figure 34 -- A cut-away of a wound wire filter with a rotating continuous backwash. Courtesy of The Leon J. Barrett Co. Figure 35 -- A bowl type centrifuge for metal working fluid purification. steel strip as thin as 0.0005 inches.17 Such a filtra tion system is shown schematically in Figure 33. CUTTING AND GRINDING FLUIDS A wide variety of methods are used successfully for the removal of contaminants from metalwork ing fluids. Gravity settling is commonly used as the only means, or may be included as a part of an over all system. Flotation is applicable to aqueous cutting and grinding fluids, illustrated previously in Figure 2, as well as to the removal of fines from aqueous fluids used in copper wire drawing. Belt type surface filters such as the one shown in Figure 10, filtering under vacuum or modified for pressure filtration, can handle large quantities of grinding debris easily. Various types of surface filters are frequently combined with gravity settling. Self cleaning filters utilizing a built-in backwash are also used. Figure 34 is an example of such a unit. Perforate basket type centrifuges are used to ex tract cutting fluids from chips, while bowl type cen trifuges like the one shown in Figure 35 are em ployed for removing fine particles from the fluid. SUMMARY Maintaining circulating oil in good operating condition is second in importance only to the quality of the oil itself. A wide selection of purifica tion systems is available, ranging from relatively simple to fairly complex, with contaminant removal efficiency varying accordingly. The choice of a cir culating oil purification system therefore depends upon many factors, including size and capacity, op erating conditions, space limitations, degree of puri fication desired, and, most decidedly, the char acteristics of the oil itself. BIBLIOGRAPHY 10. Magazine LUBRICATION, Volume 52, Number 6, "Diesel Locomotives." 11. ASTM-ASME Recommended Practices for the Flush ing and Cleaning of Marine Propulsion Turbine Lu bricating Systems. ASME Standard No. 113 (1964). 12. ASTM-ASME Recommended Practices for the Purifica tion of Marine Propulsion Turbine Lubricating Oil. ASME Standard No. 114 (1964). 13. Magazine LUBRICATION, March 1954, "Filters and Purifiers for Oil Circulating Systems." 14. Magazine LUBRICATION, July 1965, "Industrial Hydraulic Oils." 15. Magazine LUBRICATION, August 1956, "Keep Hy draulic Oils Clean." 16. Magazine LUBRICATION, Volume 52, Number 5, "Hydraulics." 17. Editorial, "Filter System Upgrades Ultrathin Strip," Steel, January 9, (1961). 18. E1-Hindi, A., "Flotation Systems for Removal of Copper Fines from Water Emulsions Used in Copper Wire Drawing," Wire & Wire Prod., October (1962). 19- Ayres, R. B., "Chip and Oil Handling," Automatic Machinery, July, p. 44-46 (1965). 20. Fairchild, D., "Heavy Duty Engine Filtration Systems," SAE Paper 734C (1962). 21. Nugent, W. M., "Lubricant and Fuel Filter Theory Operation and Maintenance," Talk before Lake Carriers Assn., Cleveland, Ohio, February, (1965). 22. Ambler, C. M., "Centrifugal Purification of Lubri cating Oil," ASLE J., January, p. 34-39 (1961). [132] DSW 202018 STLCOPCB4060085 The best anti-wear prescrip tion you can give your pumps is Texaco Rando Oil HD. They need the long-life protection of the special additives in Rando Oil. In addition to wear protec tion, Rando HD gives you the smooth performance, uniform pressure and clean system you can't expect to get with ordi nary oils. It resists oxidation. Eliminates valve gum-up. Reduces downtime. Cuts your maintenance costs. Prevents rust throughout your hydrau lic system. It is designed to prevent foam and it separates from water fast. Texaco Rando Oil is avail able in viscosities to meet every requirement. For more information, including accel erated pump wear test results, write: Texaco Inc., 135 East 42nd Street, New York, New York 10017. TEXACO IDEAS KEEP THINGS MOVING Preventive medicine for high pressure hydraulic pumps. It's fortified with special anti-wear ingredients. STLCOPCB4060086 Lubrication TEXACO INC. 135 EAST 42ND STREET, NEW YORK, NEW YORK 10017 RETURN REQUESTED BULK RATE U. S. POSTAGE PAID New York, N. Y. Permit No. 1223 .. J. MASSEY MONSANTO CHEMICAL CO. 800 NORTH LINDBERGH BL-J ST. LOUIS 66, MISSOURI 63166 TRUST YOUR CAR TO THE MAN WHO WEARS THE STAR TEXACO INC. DIVISION OFFICES ATLANTA, GA.30301 P.O. Box 1722 BALTIMORE, P.O. Box 6760 Towson, Md. 21204 BOSTON P.O. Box 149 Chestnut Hill, Mass. 02167 BUFFALO, N. Y. 14205 P.O. Box 368 CHICAGO, ILL. 60604 332 So. Michigan Ave. COLUMBUS, OHIO 43216 P.O. Box 538 DALLAS, TEXAS 75222 P.O. Box 6171 NORFOLK, VA. 23501 P.O. Box 901 DENVER, COLO. 80201 P.O. Box 2100 ORLANDO, FLA. 32802 P.O. Box 40 HOUSTON P.O. Box 430 Bellaire, Texas 77402 LOS ANGELES, CAL. 90005 3350 Wilshire Blvd. MINNEAPOLIS, MINN. 55403 1730 Clifton Place NEW ORLEANS, LA. 70160 1501 Canal Street NEW YORK 2100 Hunters Pt. Ave. Long Island City, N. Y. 11101 SAN FRANCISCO, CAL. 94111 255 California Street SEATTLE, WASH.98111 1511 Third Avenue ST. LOUIS, MO. 63119 7020 Chippewa Street TULSA, OKLA. 74101 P.O. Box 2420 Texaco Petroleum Products are distributed throughout the United States, Canada, Latin America and West Africa. DSW 202020 STLCOPCB4060087