diabasic-acids esters, chlorofluro carbon polymers; Fluorocompounds (fluoro esters) Neopentyl, polyol esters, polyphenyl ethers. (d) Soluble oils or compounds.
LUBRICATION
Lubrication and lubricants are the most important aspect for running a machine without giving pre-matured failure. It is also used to minimize power loss, heat generation, wear and tear of mechanical components as well as for smooth running of the machine. Production and productivity are very much dependent on lubrication system. This study material focuses on the subject “Lubrication”. Optimum and correct way of using lubricants are the main issue now a days. This study material will help to know how lubricants can be selected and where the use will be. Study material includes the selection of lubricants, their specific place of application, methods of using oil and grease lubrication, different lubrication equipments, etc. which are needed for any lubrication personnel to know well. Our trainees and employees will be certainly benefited by this study material.
_________________________ Prepared by Rohit Kumar & S.P.Sharma Mechanical
Prepared by: Rohit Kumar & S.P.Sharma
_________________________ Approved by Mr. K N Choubey Group Head - Mechanical
Page 1 of 30
LUBRICATION
Sl. No.
Topic
Page #
1.
What is Lubrication ?
3
2.
Function of lubricants
3
3.
Types of lubricants
3
4.
Selection of lubricants
5
5.
Principle of lubrication
10
6.
Methods of oil lubrication
12
7.
Methods of grease lubrication
18
8.
Grease lubrication equipments
20
9.
Lubricants-Handling, Storing & Dispensing
25
10.
Protective Devices
26
11.
Lubrication Fittings
27
12.
Related Safety, Care and Maintenance
28
13.
Questions for self evaluation
30
Prepared by: Rohit Kumar & S.P.Sharma
Page 2 of 30
LUBRICATION What is Lubrication? Lubrication is the science of reducing friction between two solid bodies in relative motion by interposing a lubricant between their rubbing surfaces. It is the most vital singular factor in plant maintenance. It keeps the plant young, contribute to better profits by improving the life of the wear components, equipment availability and reliability. Much work has been done in this direction my improving lubrication, mechanization, modification of the existing lubricating system, elimination of lubricant wastage and thus bringing down the consumption of lubricants and wear parts.
Function of Lubricants : The principal functions of lubricants are : •
Reduce friction.
•
Control temperature rise.
•
Control wear
•
Control Corrosion
•
Transmit Power in case of hydraulics
•
Washout debris and contaminants
•
Decrease power requirement
•
Act as a seal (Seal out contaminants)
•
Carry out heat (Sometime used for cooling)
•
Dampen Shock
Secondary results include those leading to economic benefits :•
Extended useful life of frictional components.
•
Reduction in unscheduled machine down time, resulting in increased production.
•
Lower Production, maintenance, labour and replacement cost.
•
Save energy.
Types of Lubricants : Lubricants may be gaseous, liquid, plastic or solid. Their classification according to physical state includes materials and coatings that are self lubricating. The additives listed under solids are usually not lubricants themselves but contribute important lubricating properties, when added to an oil. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION Gaseous lubricants – Air, helium, Carbon dioxide and others. Liquid lubricants – (a) Mineral oils (from petroleum crude) •
Straight or unadulterated
•
Compound with fixed oils or their derivatives
•
Compound with special additives.
•
Compounded with fixed oils or their derivatives, plus chemical additives, such as polymers and metal soaps.
(b) Fixed Oils •
Animal (acid less tallow oil, lard oils, etc)
•
Vegetable (Castor oil, rapeseed oil, Palm oil, etc)
•
Fish (Sperm oil, porpoise jaw oil, Palm oil, etc.)
(c) Synthetic fluids - Silicons, silicate esters, phosphate esters, polyglycols, diabasic-acids esters, chlorofluro carbon polymers; Fluorocompounds (fluoro esters) Neopentyl, polyol esters, polyphenyl ethers. (d) Soluble oils or compounds •
Mineral oil compounded with emulsifying agents.
•
Synthetic fluids compounded with emulsifying agents.
Semi – Liquid/Plastic Lubricants (GREASE) As per ASTM D288, grease is a solid to semi-fluid product of dispersion of a thickening agent in liquid lubricant. Other ingredients imparting special properties may be included – is known as GREASE. GREASE – BASE OIL + Thicker + Additives. Thickener : i) Soap : a) Calcium b) Lithium c) Sodium d) Aluminum Where grease is suitable ? Accessibility : If the lubricating point is difficult in accessing, Grease is suitable to use in the machine. Frequency : If the frequency of lubrication is long, then Grease is suitable. Starting Stage : In some large equipments, starting stage lubrication is ensured by grease. Type Of Product : In food, textile type industries, product may be damaged due to the presence of oil. So Grease is efficiently used. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION How does grease lubricate ? When the load is applied on the grease the soap will release from oil. The pressure again redirects the oil to go back to soap. The phenomenon is known as SWEATING. Under the load the grease is PLASTIC, and when the load is released again it is solidified. Different form of Greases : •
Soap thickened mineral oils.
•
Soap thickened Mineral oils with special additives.
•
Yarn fibers saturated with fluid grease.
•
Semi fluid grease.
•
Mineral oil thickened with non soap gelling agents.
•
Block grease (non flowing at room temperature).
Solid Lubricants : Solid lubricants are rarely used directly, commonly it is added with other lubricants to increase its some of the properties. Some Examples of Solid lubricants are Graphite, Molybdenum disulfide, mica, talc or soap, lead carbonate, wax, etc. Additives : Additives are the substances which are added with the lubricants to fortify some of their properties. Some of the Additives are : Metallic phosphates, few additives, metallic oleates, metallic chlorides, Metallic sulfides, metallic stearates, metallic oxides and metallic oxalates.
Selection of Lubricants Factors to be considered to select a correct lubricant are :• •
The operating factors of an equipment, such as speed, load and temperature. Equipment condition-whether old or new, etc.
•
Compatibilitiy of the lubricant with materials in contact.
•
Operating environment - Dust, Hot Water, etc.
•
Operating condition – continuous or intermittent.
•
Lubricants application methods, Lubricant maintenance system.
•
Clearances between moving parts.
•
Type of part to be lubricated - Gear, bearing, sliding surface etc.
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Page 5 of 30
LUBRICATION Grease Vs. Oil In most applications there is no choice. In some cases both can be used. Compared with grease oil is better coolant, generates less internal friction, is easier to handle and apply, and forms a more uniform film. But there are certain applications where grease has the advantage. Grease
Oil
• Stays longer
• Has less internal friction.
• Drips less
• Serves high speeds
• Serve certain extreme condition.
• Serves close tolerance.
• Provide better sealing
• Serves as a coolant
• Requires less frequent
• Flushes away contaminants.
• Lower costs
• Lower costs
Selection parameters for oil and grease Parameters Load
Grease OK
Oil OK
0
Upto 900
Temperature
Upto 120
Speed
Low to medium for R. C. Any speed, n x d factor Bearing, n x d factor upto 5,50,000 upto 35,000
Inaccessibility of location
Good
Bad
Dust environment
Good
Bad
Vertical Bearing (to protect from dropping, Good Hydrostatic lubrication)
Bad
At low temperature
Bad
Good
When pressure of lubricant is to be varied
Bad
Good
Complex layout of lubrication .
Bad
Good
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Page 6 of 30
LUBRICATION Important Properties of Oil •
Proper fluidity or plasticity under conditions of operation.
•
Film strength commensurate with loads.
•
Chemical stability.
•
Adhesiveness to bearing surface.
•
Lubricity or oiliness or slipperiness to the degree required by operating factors.
•
Purity i.e. freedom from contaminants that detract from the efficiency of the lubricant.
•
Non-corrosive characteristics.
•
Rust proofing capability.
•
Resistance to water wash.
•
Resistance to foaming.
•
Good sealing properties.
•
High viscosity index.
•
Fire resistance.
•
Minimum of volatility or out gassing.
•
Resistance to the effect of nuclear radiation.
•
Good emulsifying qualities.
Important Properties Of Grease: Penetration : Grease hardness is identified by the following chart. NLGI GREASE CLASSIFICATION
Ranges Are The Penetration In Tenths Of A Millimter After 5 Seconds At 770F (250 F) Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION Consistency : Consistency is defined as the degree to which a plastic material resists deformation under the application of a force. In the case of lubricating greases it is the measure of relative harness or softness, and may indicate something of flow and dispensing properties. As per National Lubricating Grease Institute (NLGI) grade, Consistency, similar to viscosity varies with temperature. Cone Penetration : The cone penetration of grease is determined with the ASTM (American Standard of Testing Material) Penetrometer. After sample is prepared, the cone is released and allowed to sink into the grease under its own load for 5 sec. The depth the cone has penetrated is the reads in tenths of a millimeter and reported as the penetration of the grease. Since, the cone will sink further into softer greases. ASTM penetrations are normally measured at 25 deg. C. Dropping point : The dropping point of any grease is the temperature at which a drop of material fall from the orifice of a test cup under prescribed test condition. Resistance to oxidation : Resistance to oxidation is an important characteristic of grease intended for use in rolling element bearings. Both the oil and fatty constituents in grease oxidize, the higher the temperature faster is the rate of oxidation. When grease oxidizes it generally acquires a rancid or oxidized odour and darken in colour. Simultaneously, organic acids generally develop and the lubricant becomes acid in reaction. These acids are not necessarily corrosive, but may affect the grease structures causing hardening or softening. Resistance To Water : The ability of a grease to resist water washout under conditions where water may splash or impinge directly on a bearing is an important property. Oil Separation : The resistance of a grease to separate oil from thickener involves certain compromises. When greases are used to lubricate rolling contact bearings a certain amount of bleeding of oil is necessary in order to perform lubrication function. On the other hand, if the oil separates too much readily from a grease in application devices, a hard, concentrated soap residue may built up which will clog the devices and prevent or retard the flow of grease to the bearing. Further leakage of separated oil from bearings can damage materials in production or equipment components such as electric motor windings. In application devices, such as central lubrication system and spring loaded cup when pressure is applied on the grease on more or less on continuous basis, oil can be separated from greases by a form of pressure filtration. The pressure forces the oil through the clearance spaces around plungers, piston or spool valves, but since the soap cannot pass through the small clearance it is left behind. This may result in blockage of the devices and lubricant application failure. E.P. and wear preventation test : As per ASTM (D2596) the standardized test procedure to determine E.P properties of greases using the four ball extreme and the Timken (ASTM D 2509) load tester. The two extreme pressure tests are considered to be capable of differentiating between greases having low, medium or high level of extreme pressure properties. The wear prevention test is intended to compare only the relative wear. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION LUBRICATING GREASE CHARACTERISTICS
Prepared by: Rohit Kumar & S.P.Sharma
Page 9 of 30
LUBRICATION
PRINCIPLE OF LUBRICATION To maintain a film of Lubricant between the surfaces in running condition any one of the following principle of lubrication prevails. •
Hydro dynamic Lubrication
•
Hydrostatic Lubrication.
•
Elasto-hydrodynamic Lubrication
Hydrodynamic (Thick film) Lubrication : The formation of a thick fluid film that will separate two surfaces and support a load as the two surfaces moves with respect to each other, internal friction in the fluid causes it to be drawn into the space between the surfaces. The force drawing the fluid into space A is equal to the force tending it out, but since the cross sectional area the outlet section is smaller than inlet, the flow of fluid is restricted at the outlet. The moving surface tries to “compress” the fluid to force it through the restricted section with result the pressure in the fluid rises. The thickness of the film in this case is high enough to eliminate any contact between the surfaces, thus the coefficient of friction micron is even in the order of 0.005. Development Of Hydrodynamic Film In A Journal Bearing 1. Firstly the machine is at rest with the oil shut off and the oil has leaked from the clearance surface. Metal to metal contact exists between the journal and the bearing. 2. Secondly, when the machine has been started and the oil supply turned on filling the clearance space, the shaft begins to rotate counter clockwise and friction is monetarily high so the shaft tends to climb the left side of bearing. 3. Finally , as it does this, it rolls onto a thicker oil film so that the friction is reduced and the tendency to climb is balanced by the tendency to slip back. As the journal gains speed, it draws more oil through the wedge shaped space between it and the bearing. Pressure is developed in the fluid in the lower left portion of the bearing that lifts the journal and pushes it to right. Under steady condition the upward force developed in the oil film just equals the total downward load and the journal is supported in the slightly eccentric position. Hydrostatic film Application : One of the more common applications of the hydrostatic principle is an “oil lifts” for starting heavy rotating machines, such as steam turbines, large motor steel mills and rotary ball and rod mills. Because metal to metal contact exists between the journal and the bearings when the journal is at rest, extremely high Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION torque may be required to start rotation and damage to the bearings may occur. By feeding oil under pressure into the pocket machined into the bottom of the bearings, the journal can be lifted and floated on fluid films. When the journal reaches a speed sufficient to create hydrodynamic films the external pressure can be turned off and the bearing will continue to operate in the hydrodynamic manner. Elasto-hydrodynamic Film Lubrication : In the case of rolling contact bearing as the ball or roller on their raceways, the lubricant is carried into the convergent zone approaching the contact area and as the pressure on oil increases. The viscosity increases. As the viscosity increases, the pressure further increases. This hydrodynamic pressure developed in the lubricant is sufficient to separate the surface at the leading edge of the contact area and as the lubricant is drawn into the contact area and as the lubricant is drawn into the contact area the pressure on it increases further together with the viscosity. Due to this high viscosity and the short time required for the lubricant to be carried through the contact area, the lubricant cannot escape and separation of the surface can be achieved. Hydro-dynamic & Hydrostatic films are for sliding contact surfaces whereas Elasto-hydrodynamic film is for rolling contact surfaces. Boundary Lubrication : If none of the above these conditions exists the condition will be of boundary lubrication. Boundary larger lubrication is obtained when the thickness of the lubricating film is of the same order of magnitude as the individual oil molecules. This condition may present when the quantity of oil is insufficient or the relative movement between surfaces is too low. The coefficient of friction micron in this cases is high-as high as 0.1, and on the incipient metallic contact, can rise to 0.5. When the coefficient rises, friction losses also increases. These are converted into heat, which raises the temperature of the lubricant, thereby reducing its viscosity so that the load carrying capacity of the film is even lower in the most case so low that the surfaces seize together.
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LUBRICATION
METHODS OF OIL LUBRICATION We will group the different methods used for applying lubricating oil into moving parts under three types : 1. Once through oiling / All loss method. 2. Oil reservoirs / Reuse method. 3.
Circulating oil systems
Once through oiling : Once through oiling is so named because the oil passes through the bearing only once and is lost for further use. Method of this type includes oil cane lubrication, drop feed oiling, gravity feed bottle, wick feed lubrication. a) Oil can Lubricator : This is the direct application of oil to a moving machine part from a hand oil cane. It is used for small bearings, chains. This method has limitations. The excess oil runs off bearing. The parts operate with insufficient oil until next oiling.
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LUBRICATION b) Drop feed Oilers : When a more uniform supply of oils is required, a drop feed oiler may be used. It consists of a shut off lever, feed adjustment, oil chamber, needle valve and sight glass. The dropping of the oil through the drop feed oiler can be regulated and checked from time to time see that the oil is continuing to feed properly.
c) Wick Feed Oiler : The wick feed oiler consists of an oil reservoir and a wool wick. The wick draws oil from an oil cup by the capillary and siphoning action of the wick and feed it into an opening in the bearing. The amount of oil being delivered to the bearing can be regulated by changing the size of the wick. The reservoir should be kept well filled, because the rate of oil feed depends on level of the oil in the reservoir.
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LUBRICATION d) The Bottle Oiler : The bottle oiler consist of an inverted glass mounted above the bearing and filled with a sliding pin which rests on the journal. When the journal rotates, it vibrates the pin. The vibration in encourages the flow of oil from bottle to the bearing through the space between pin and its sleeves.
Reuse Methods : As referred to “all loss” lubrication, the lubricants supply to the bearings gradually leaks away and is not reused. In short, the bearing passes through the region of mix film lubrication and operate much of the time under boundary conditions. A closer approach for maintaining a safe oils supply may be accomplished with application devices such as wick feed oilers, drop feed cups bottle oilers. Even with regular application of small amount of lubricant, their film bearings require proper selection to control wear and provide satisfactory service life. Reuse method of oil application include circulating supplying lubricant for one or more machine and self contained system such as bath, splash, food and ring oiling. a) Chain Oiling : Chain oiling is similar to ring oiling except that a small linked chain is substituted for ring. Chain will carry larger volume of oil than does the ring. b) Oil Collar : An oil Collar may be used to carry oil from reservoir to journal which are rotating at high speed so that rings and chains would slip. The collar fastened to the journal rotates carrying the oil to an over head scraper which removes and distribute oil to bearing and gears. c) Ring Oiling Method : In ring oiling method, a metallic ring larger in diameter than journal rides on it and turns as it rotates. The ring dropping into oil, carries oil to the top of the journal where it flows along and around the journal providing lubrication before returning to the reservoir.
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Page 14 of 30
LUBRICATION
SHAFT
RING
d) Splash Oiling : In this method, some moving parts is in direct contact with oil in the bottom of the casing. As the moving part turns, it splashes and carries the oil in to the other parts within the casing keeping them well supplied with lubricant. This is very reliable method of lubrication.
In I.C. engine compressor, the crankpin connecting rod which coming in contact with oil level during rotation splashing out the oil to the surrounding and oil is carried out to the desired locations. In gear boxes, one gear dips into the oil and carries to the moving parts and to the meshing zones of the gears. The gear teeth carry oil directly to some gears and splash it to others and to collecting through which leads it to bearing not reached by splash. In all method of reservoir lubrication it is important that the reservoir be checked for proper oil level either by dip stick or gauge glass. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION e) Mist Oil Systems : In oil mist lubricators, oil is atomized by low pressure (0.7 to 3.5 bar) compressed air forming a practically a dry mist or fog, that can be practically a dry mist or fog, that can be transported relatively long distance in small tubing. When the mist reaches the application point it is condensed or collapsed into larger particles that wet the surface and provide lubrication.
CENTRALISED OIL CIRCULATING SYSTEM : System comprising an assembly of the following units: a) Reservoir b) Pump c) Cooler d) Filter/Strainer e) Different Gauges etc. This system explains a typical example. Returning oil drains to a settling compartment, enters into reservoir. Water and heavy contaminants settle at power point from which they can be drained. Particularly purified oil overflows a baffle to a clean oil compartment. The clean oil pumps takes oil through a suction strainer and pumps it to a cooler and then to Bearing, Gears and other lubricated parts. The pressure desired in the oil supply pipings is maintained by means of a relief valves which discharges to the reservoir. A continuous by-pass purification system takes 5 to 15% of the oil in circulation system through a pump from point above the maximum level of separated water in the reservoir and pumps it through a suitable filter back to the clean oil compartments.
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LUBRICATION
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Page 17 of 30
LUBRICATION METHODS OF GREASE APPLICATION : There are three methods of applying grease : 1. By hand 2. By hand operated mechanical devices like grease gun, which delivers the grease to one point at a time. 3. By centralized grease systems which supply a number of points at a time from a central reservoir. Hand Application : As the name implies is the application of the grease directly to the parts by hand. Ball and Roller bearings are greased by fingers into the space between the balls and rollers. Grease application is also done to open Gears and Guiders. Hand Operated Mechanical Devices : (a) Grease Cup : It consists of a small reservoir for holding the Grease and pressure is exerted by screwing it down and forcing the grease into the Bearing.
GREASE CUP
(b) Grease Gun : The grease gun is a very popular device for grease lubrication at the various lubricating points. The gun delivers the grease by operating the lever, in turn grease is forced into the fittings to reach the bearing surface.
GREASE GUN
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LUBRICATION Centralised Grease Lubrication System : (a) Single line system : The three way valve, operated manually or automatically, either directs pump pressure into the supply line or relieves the pressure in the line to permit the spring return to reset the valves.
(b) Dual line (FARVAL) system: The four way valve operated manually or automatically directs pump pressure to one line and then the other. When one line is pressurized the other line is relieved.
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LUBRICATION (c) Multi line (DELIMON) system : The gear train moves the cam plate which in turn moves each plunger up & down and creates suction & delivery. During delivery the lubricant is forced out to the outlet pipe.
GREASE LUBRICATING EQUIPMENTS (a) H5A Grease Gun : It is a small screw plate pinned Grease gun. It is lever type. Capacity – 5 lbs. Max. Pressure- 2,500 psi. with 7 ft. hose with ¼” hose fitting or coupler in delivery line. Discharge – 1/3 ozs or 10 gm/stroke. Height – 13.5”, Length-21”, Width – 5.25”. Operating Instructions For H5A Grease Gun : a) Fasten the hose coupler on the fitting to be lubricated. b) Move the handle up & down until lubrication is completed. c) Release the handle, it will automatically move to its neutral position, releasing pressure in the hose and permitting the hose to be uncoupled from the fitting. d) Remove coupler, pulling it to one side and off. Note – If the valve does not come out easily, further relieve pressure in the hose by opening the air pressure release valve, Then remove the coupler. e) After using the gun pump slightly dampen a ray with oil and mesh the hose. Then, wipe off the hose drip. This step will prolong the life off your hose. Note : This gun builds 2,500 lbs. of air pressure. Should this pressure not be enough to free a bearing, the bearing should be removed and cleaned. Make sure that the lubricant is packed solidly, so no air pockets can form. f) Replace follower on the stem, and turn the crank to the right-clockwise-until the fill lower is back in position. g) Replace cap on cylinder. h) Open the air relief valve. Turn the crank to the right until lubricant begins to ozze out at the valve opening. Then close the valve. i) Swing the pawl lever and handle up, into normal operating position. j) Move the handle up and down until lubricant appears at the hoes coupler. CAUTION : Never use a pipe extension or other attachment on the lever to secure more pressure. Never jump on the lever. Maintenance Instructions For H5a Grease Gun : Lubricating an extra tight bearing : After lubricating an extra tight bearing, swing the pawl lever and handle unit back on to the cylinder to prevent damage to he pawl level, stem, head casting, follower or other working parts of your lubricating gun. Removing air pockets : - Continued pumping will remove normal air pockets. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION - Larger air pockets may be quickly removed by opening the air release valve and turning the crank slightly to the right. Correcting the faulty gun operation : If there is lubricants in the gun but it can not be pumped out : - Remove the hose. - Operate the pump. If lubricant flows, the hose is plugged up. Clean or replace hose, as necessary. If lubricant does not flow, the pump screen is probably clogged with foreign material and should be cleaned. NOTE : Foreign particles in the lubricants may score the piston or casing, and cut down the pump pressure and operating efficiency. (b) Air Operated (Goliath) Grease Pump : It is an air operated grease gun. It has heavy duty construction for longer life in difficult operating condition. Front caster wheel and rear wheel tyres are made of rubber to suit in rough plant, garage floor, etc. It is supplied with 7 feet hose with control valve. Helix arm and worm gear construction assure positive mechanical priming to handle heavier grease even in cold weather with no air pockets. The rugged air motor develops greases pressure 33 times the air pressure applied.
Other Features : a. Capacity - 40 lbs. b. Maximum pressure – 5,000 psi. c. Minimum air pressure required – 40 psi. d. Discharge – 14 ozs / minute average e. Height – 31.5” f. Width - 17.75” g. Length – 39” h. Outlet has double check valve with 3/8” & ¼” bush to connect ¼” hose. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION (c) Farval Pump :
It is a hand operated dual line pump. 2 to 200 bearing points can be lubricated at a time up to ¼ mile distance. It’s selector is 4/2 way hydraulic change over valve to supply lubricant in both lines alternately when pressurized by handle of the pump. It has 2 suction port with strainer, two check valves for double acting, inlet line to tank for excess lubricant for easy handling of selector. It requires less maintenance. It is used for centralized lubrication, remote and difficult approach & normal industrial machines etc. Other Features : a) Capacity - 4.5 lbs., 8.25 lbs or 12.5 lbs. b) Discharge - 10 cc/stroke of handle. c) Maximum working pressure – 200 kg per square cm. Maintenance : a) Use clean lubricants. b) Do not over pressurized. c) Relief air pocket by bleeder valve when pressure is not rising, also check the pipes.
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LUBRICATION d) FWA Grease Pump : Application : Lubrication of not more than 36 points with small quantities of grease, particularly for conveyor system, presses, construction machinery etc. Reliability : Every lubrication point receives the correctly metered quantity of lubricants either continuous or at particular intervals, at our choice. No lubricating point is over or under lubricated. The lubricant fed to the lubricating point is always clean. Economy : Manual lubrication is more costly. Advantages : Transport of lubricant through piping is clean and avoid unnecessary losses in transferring from one container to another, very much suitable for lubricant conservation. Lubricants cost are reduced. Plant remains cleaned. Work Design : All lubrication lines are plumbed directly from the pump to the lubrication points. The lubricant is metered by the pump, the quantity being adjustable. The pump may be operated manually or by an electric motor. Mode of operation : The worm which is fitted to the drive shaft engaged the worm wheel, which is attached to the vertical distributor sleeve. This sleeve rotates the scraper with wedge plate, which pushes the greases out of the container through the strainer into the Gear Box. The rotating movement of distributor sleeve is transmitted to the distribution cylinder through the two Bevel gears which has transmission ratio of 1:1. The cam plate which is fixed on top of the distribution cylinders turns with the latter and moves each cylinder up & down once or three times per revolution depending on the rise of the cam plate (single/three). During the suction stoke a quantity of lubricant is drawn through the suction port of the distribution cylinder. During the feeding stroke the lubricant is forced out of space through the pressure port into the outlet ports. Care & Maintenance: 1. The strainer is to be cleaned at regular time intervals. 2. Do not allow the jute, rust, bolts etc. to be fallen inside the grease container. 3. Top lead of grease container is to be cleaned time to time. 4. The direction of rotation must be clockwise from the back side of the motor, and it must be ensured. 5. All pipes are to be cleaned prior to the installation, by pressurized air. 6. Grease container must be filled when about 3/4th of its grease has been used. 7. Before putting power “ON’ to the motor, motor coupling should be turned manually and watch for any abnormal alarming. 8. In case of pumping unit getting higher leakages all related bolts and screws should be tightened. Discharge line should also be checked for the free movement of grease in the pipes, pipes are coming freely or not. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION (e) CENTRIFUSE (OIL – RECLAMATION) The principle of separating and purifying liquids by centrifugal force in the disc type centrifuge is equally easy to understand, for the discs divide the liquid into thin layers so that centrifugal force can act on the thin liquid strata most. In the bowl of a centrifugal oil purifier, a mixture of oil water and dirt will be separated by centrifugal force into three layers. Each whirling particle or droplet will lend to “fly out” like the ball on the string. The dirt will go to the periphery of the bowl. The water will form the next layer and the oil. Lightest of the three, will collect at, and be discharged from, the point nearest the centre. Techniques of Separation: Definitions : Throughput : This means the quantity of liquid supplied per unit time. The throughput is given in cu.m/h or I/h (lmp.galls/h). Reception ability : This means the largest liquid quantity that the bowl can treat per unit time, expressed in cum/h or 1/h (Imp. Galls/h) Clarification : A liquid-sludge separation in which the machine is used for separating off particles, normally solids, having a higher specific gravity than that of the liquid. Purification : A liquid-liquid separation in which the machine is used for separating two intermixed liquids, which are insoluble in each other and have different specific gravities. Solids with specific gravities higher than those of the liquids can be separated off at the same time. Factors influencing the Separation : Difference in Specific gravity : The centrifugal force acts on all particles proportionally to their specific gravity. This applies to solid particles as well as to fluid particles. The greater the difference in specific gravity, the easier the separation. Size and shape of Particles : The larger the particle, the quicker is the sedimentation. The particles to be separated off must not be so small that the mixture is getting near colloidal state. The smooth and round particle is easier separated off than the irregular and elongated one. Rough treatment such as in pump can split the particles, with reduced size and separating speed as a result. Viscosity : The more fluid a liquid is, the quicker is the separating process and the better the separation. In other words, low viscosity improves the separation result. The viscosity can in many cases be reduced by heating. Time in centrifugal field : If the separation is not satisfactory, the throughput must be reduced. Lower throughput gives a better separating result.
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LUBRICATION LUBRICANT - HANDLING, STORING AND DISPENSING Observing simple precautions and procedures in the handling, storing and dispensing of lubricants can achieve significant economic and operating benefits. Economic benefits can be obtained by the following preventive factors : a) Leakage or spill from damaged or improperly closed containers. b) Contamination due to exposure of the lubricants to dust, metal particles and moisture. c) deterioration caused by storage in excessively hot or cold environment. d) deterioration due to prolonged storage. e) residual oil or grease left in containers at the time of refilling. f) mixing different brands and types of lubricants that are incompatible. g) leaks, spills and drips when changing a reservoir or lubricating a machine. Handling : Drums can be unloaded without damage from trucks by sliding them down with the help of wood or metal skids (05 mm * 2.5 mm). Before unloading the brakes of the truck should be set firmly and wheel should be blocked. The skid should be securely attached to the truck. NOTE : a full oil or grease drum weighs about 204 kg. A drum standing on end with bungs up can collect rain water or condensed atmospheric moisture inside the too annular. This water can gradually be drawn in around the bungs by the breathing of the drums as the ambient temperature rises and falls. This can occur even with the bungs drawn tight and the temper proof seals in place.
Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION PROTECTIVE DEVICES DEVICES
TYPES a) Dipstick
1. Level Gauge
b) Glass Tube c) Dial (float actuated pneumatically operated)
2. Level Switch 3. Pressure Gauge
a) Float actuated b) Sensing probe a) Borden type b) Diaphragm a) Bellow actuated
4. Pressure Switch
b) Piston actuated c) Borden Tube a) Standard high lift spring loaded
5. Pressure Control Valve
b) Direct operated diaphragm c) Pneumatic control diaphragm
6. Flow Switch 7. Spring Relief valve 8. Differential pressure Switch
a) Wen Actuated b) Differential Pressure Switch with orifice a) Standard b) Die lift a) Bellow actuated b) Piston actuated a) Bi-metallic
9. Thermometer
b) Vapour Pressure c) Mercury Inserted
10. Temperature Control Valve.
Prepared by: Rohit Kumar & S.P.Sharma
a) Direct operated b) Pneumatic Controlled Diaphragm
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LUBRICATION LUBRICATION FITTINGS
APPLICATION
Single end connector
For connecting two pipes or tubes
Double ended connector
For connecting two separate pipes
Ferrule
For connecting treadles tubes
Benzo
For controlling flow by adjusting radial hole
Grease Button
Used while inserting grease to machine
Grease Coupler
Used along with grease button while inserting grease
Plug
To close the end of pipe line
Nipple
To connect two pipes having internal threads
Socket
To connect two pipes having external threads
Tee
Connects three pipes
Cross
Connects four pipes
Elbow
Connects two pipes at 900 angle
Bend
Connects two pipes at 900 angle or at more or less angle
Steel pipe
Where fixed pipe installation is required
Copper tube
Where more flexibility in pipe lines are required
Nylon tube
Where lay-out is not fixed or for temporary mounting
Flexible hose
In high pressure lines, where pipe can not be fixed
Bushing
Pipe is being supported
Union
Two pipe end can be connected without turning the pipes
Hose clamp
Used to clamp hoses
Jublee Clamp
Used to clamp hose
Hose compression sleeve
Used to connect hoses at high pressure lines
Teflon tape
Used to make leak proof joint at threaded portion
Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION RELATED SAFETY, CARE & MAINTENANCE 1. Whole activity of lubrication should be done under some responsible person. 2. Recommended lubricants should be used only. 3. One grade of oil should not be mixed with other grade. 4. Oil should be protected from contaminants. 5. Oil should be allowed to work under recommended temperature. 6. Oil should be checked, clean, filtered and replaced in specified interval. 7. Oil barrel should be handled properly. While unloading from carrier, care should be taken to avoid damage. Skidding of drums should be avoided. 8. Barrels should be stored categorically based on its grade, use, etc. 9. Barrels should be kept under some roof. It should be avoided from direct sun, rain water, moisture, etc. 10. Barrels should be kept horizontally, keeping their bungs horizontal. 11. Lids of barrel must be kept fully tight to avoid entry of water vapour, air, water, etc. 12. Oils should be transferred from barrel to machine only through transfer pump. Direct contact with operating personal should be avoided. 13. Lubricating personnel must take absolute care while handling, filling oil, for its cleanliness. 14. Spillage of oil must be stopped. 15. Shop floor must be free from oil and grease to avoid slippage. 16. Tools, tackles, lifting devices should be free from lubricants. 17. Proper pressure rating of lubricant fittings should be used only. 18. Pipe lines must be flushed properly before using fresh oil. 19. Filters, strainers, coolers, etc. must be attended in regular interval. 20. Pressure relief valve must be adjusted at right pressure in case of centralized lubrication system. 21. Pump should not be allowed to rotate in reverse direction. 22. Condensed water and other impurities must be drained from reservoir at regular interval. 23. Oil level, oil pressure and other leakage should be checked regularly. 24. Hoses should be fitted in proper manner only. 25. Flareless joint should be connected carefully to avoid leakage. 26. All warning and protecting devices should be in working condition. These should not be bypassed from system. 27. Fire extinguisher must be kept ready at different locations to avoid fire hazard. 28. Oil godown should be properly ventilated, clean, lighted and free from fire hazard. There should be no chance of electrical short circuit. Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION 29. Oil should be filled up only up to required level. 30. More greasing should be avoided. It normally damages lubricating seals and packings. 31. Some oils are injurious for our eyes and skin. Avoid touching of oil. 32. Lubrication oil should not be used for cleaning components. Proper solvents should be used only. 33. Lubricants are too costly, avoid misuse of lubricants. 34. Lubricating oil should not be used in hydraulic system. Hydraulic oil has some specific properties, which a lubrication oil does not have normally. 35. While using coupler, points of grease buttons should be cleaned properly.
Prepared by: Rohit Kumar & S.P.Sharma
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LUBRICATION Questionnaire for self evaluation 1. What are the functions of lubrication? 2. What are the four categories the lubricants? 3. What are the composition of grease? 4. Mention different factors on which selection of lubricants depend. 5. Mention important properties of lubricating oil. 6.
Mention important properties of lubricating Grease.
7. Mention principle of Lubrication. 8.
In case of Boundary lubrication the entire load rests on metallic contact, (T/F)
9. Mention different methods for oil lubrication in which oil is not being reused. 10. Mention different methods of oil lubrication in which reservoir is required. 11. Mention two methods of oil lubrication used for centralized lubrication system. 12.
Mention different methods of grease lubrication.
13.
Name five components of a H5A grease pump.
14.
Write different points to take care for the best performance of this grease pump.
15.
Name different components of an air operated grease pump.
16.
Write different points to take care for he best performance of this grease pump.
17.
Name different components of a Farval grease pump.
18.
Write various points to take care for the best performance of this grease pump.
19.
Name components of a FWA grease pump.
20.
Write different points to take care for the best performance of this grease pump.
21.
Name different components of a centrifuge.
22.
Mention four factors which influences the oil selection .
23.
What are the common problems related with lubricant handling and dispensing?
24.
What are the safety related requirement of a OIL GODOWN ?
25. What are the conventions maintained in TISCO for proper storing and dispensing of Lubricants ?
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