Lubricating Oil and Petroleum Blends by SAAD ABDUL WAHAB

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LUBRICATING OIL 

LOBP Schematic

1. Lubricating oil

Lube oil is designed to perform lubrication of moving parts, cooling, cleaning, corrosion control, and etc. In times when saving energy and resources and cutting emission have become central environment matters, lubricants are increasingly attracting public awareness apart from important applications in internal engines vehicle and industrial gearboxes, compressors, turbines or hydraulic systems there are vast number of other applications which mostly require specifically lubricants.

The two basic categories of lube oil are mineral and synthetic. Mineral oils are refined from naturally occurring petroleum, or crude oil. Synthetic oils are manufactured polyalphaolefins, which are hydrocarbon-based polyglycols or ester oils. Although there are many types of lube oils to choose from such as vegetable oil, solid lubricants, graphite powder , teflon, mineral oils are the most commonly used because the supply of crude oil has rendered them inexpensive; moreover, a large body of data on their properties and use already exists. This chapter will focus on mineral-based lube oil.

On average lubricating oils which quantitatively account for about 90% of lubricant consumption consist of about 90% base oils and 10% chemical additives and other components. Lubricating oils are an important area of petroleum industry. These are used for the purpose of lubrication in different machines and engines. Sliding action between the different parts causes energy losses, wear and tear due to friction. To overcome these resistances a film of lubricating oil introduced which decreases energy losses and increase life of mechanical devices.

Petroleum based lubricating oils are produced by the vacuum distillation of atmospheric distillation residue or bottom product.


1.1. Purpose of Lubricating Oil

Lubricants perform the following key functions.

1. Reduce friction 
2. Transfer heat 
3. Carry away contaminants 
4. Prevent corrosion 
5. Transmit power 
6. Works as hydraulic fluids 
7. Reduce wear 
8. Seal for gase 

1.2. Components of lubricating oil

Lubricating oil having two parts,

1.2.1. Base Oil

Base oils are the most important components of lubricants. As a weighted average of all lubricants, that account for more than 95% of lubricant formulations. There are lubricant families (e.g. some hydraulic and compressor oils) in which chemical additives only account for 1% while the remaining 99% are base oils. On the other hand, other lubricant can contain up to 30% additives.

Petroleum lubricating oils are made from the higher boiling portion of the crude oil that remains after removal of the lighter fractions. They are prepared from crude oils obtained from most parts of the world. These crude oils differ widely in properties. Crude oil generally consists of many thousands of single components and these are reflected in the processing of each fraction.

1.2.1.1. Base Oil categories

1.2.1.1.1. Paraffinic

Paraffinic base oils are made from crude oils that have relatively high alkane contents. The manufacturing process requires aromatics removal.

Paraffinic base oils are characterized by their good viscosity/temperature properties and good stability. They are frequently referred as Solvent neutrals (SN).

1.2.1.1.2. Naphthenic

Naphthenic base oils are made from a more limited range of crude oils than paraffinic. Important characteristics are low pour points, because of wax free nature and excellent solvency power. Their viscosity/temperature properties are inferior then paraffinic (low to medium VI).

1.2.1.1.3. Synthetic

1. Polyalphaolefins 
2. Alkylated aromatics 
3. Polybutenes 
4. Polyolesters 
5. Polyalkyleneglycols 

1.2.2. Lube Oil Additives

Oil additives are used to improve the base oil (or "base stock") into a better performing lubricant. By utilizing the same base stock, many different oils can be manufactured, each with its own unique properties. Different additives are used depending on the application, e.g. the oil for a direct-injected diesel engine in a pickup truck (API Service CJ-4) has different additives than the oil used in a small gasoline-powered outboard motor on a boat (2-cycle engine oil).

Combination of different additives and their quantities are determined by the lubricant type and the specific operating conditions. Amount of additives may reach 30%

IMPORTANT ADDITITIVES AND THEIR FUNCTIONS

Additive :

1. Name 
2. Characteristics 
3. Detergency & cleaning action 

Phenaltes,Sulphonates, Naphthenates

Interacts with varnish or sludge to neutralize and solubilize.

Dispersant

PBI (Polyisobutylene) Succinimides

Dispersants are soluble in the oil and have a polar end which attracts and binds to contaminants preventing settling and adhesion to metal surfaces.

Antifoaming 

Silicone Polymers (very low concentrations)

Not really necessary for diesel engines in properly designed systems, but provides anti-foam in gearbox and also at the refinery during blending.

Pour Point depressant

Polymethylacrylate

Used in SAE 30 grades and below to ensure point criteria are met.

Anti-wear load carrying

ZDTP (Zincdialkyldithiophosphate)ZDDP (Zincdiethlydithiophosphate)

Chemicals react with surfaces forming films which have slower shear strength than parent metal.

VI Improvers 

Polymers of: Methacrylate Acrylate Olefin Styrene-Butadiene

Increase in relative viscosity more at high than low temperature.

Rust and corrosion inhibition 

Sulphates, Thiourea type chemicals

Chemically absorbed onto bare metal surfaces providing protection and neutralization.

1.3. Processing 

PHOL has three Base stock storage tanks (400NHVI, 650MVI and BSHVI). Bright stock BSHVI is either mix with 400NHVI or 650MVI and pumped by gear pumps to blending kettles. These kettles have a cylindrical shape having bottom is conical. Kettles are equipped with steam coils to heat the oil at 55-60oC for proper blending temperature.

Complete LOBP Layout

Blending in kettles is done in three ways: 

1. By the passage of air (from compressor having flow rate 50-70 kg/cm2) 
2. By an Agitator 
3. By circulation of oil (gear pump takes oil from the bottom, then circulate it to the top of the kettle). 

Process flow diagram of LOBP with Inline Blending to Packaging

1.3.1. Addition of additives:

Additives are added by small dumping tanks connected by circulation pipelines. When the circulation pump starts, it also sucks all the additives from the tanks by the flow base oil and using air pressure.


1.3.2. Lube Blending

Blending is a process of mixing two or more components to achieve a desired chemical and physical property. A blend consists of two or more oil stock combined with an additive.

Mostly, batch process is used for lube oil blending, different grade of engine oil and industrial lubricants are prepared. There are four blending vessels each have a capacity of 6756 liter. Base oil is pumped from the storage tank to the blending kettle. Additives and viscosity index improvers are pumps into the blending kettle; viscosity index improver is pumped with a mixture of base oil and additives. Additives heated by means of steam coil fitted near the bottom of the kettle blending temperature is about 600C and higher temperature is avoided to prevent thermal degradation of oil and additives. Temperature of oil is maintained by circulation and by mechanical mixing which is done by motor driven impeller. The oil is mixed from ½ to 1 hr, after mixing the sample is check for their required specification of required grade, from where it is pumped in to storage tank, from where it is pumped through series of filter into the can filling machine. 

Blending Mechanism involves kettles and steam.

The impeller in a process vessel produces a high velocity stream and the liquid is well mixed in the region close to the impeller because of the intense turbulence. As the stream slow down, while entering other liquids flowing along the wall. There is some radial mixing, as large eddies breakdown to smaller ones, but there is probably little mixing in the direction of flow. The fluid completes a circulation loop and return to the eye of the impeller where vigorous mixing again occurs.

The mixing time for propeller seem high as compare to the turbines, but of course the power consumption is more than an order of magnitude lower at the same stirrer speed.

When gas bubbles, liquid drops or solid particles are dispersed in a liquid, the blending time for the continuous phase is increased, even if the comparison is made at the same specific power input. The effect increases with viscosity, and for viscous liquids the blending time can be up to twice the normal value when the gas hold up is only 10%.

TRANSFORMER OIL 

1. Transformer Oil

“Transformer oil is a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It was used in transformers, capacitors, fluorescent lamp ballasts and switches, etc.”

Electrical or Transformer oil comprise of the base oil category. Electrical oil or transformer oil are used in industrial transformer for electrical insulation and heat transfer. This oil has excellent low temperature properties (pour and cloud point) beside these they have low to medium viscosity index and most importantly,

Good electrical properties

Resistivity or Insulation

Dielectric constant

Transformer oil is an important ingredient in the energy sector. Transformer oils are like as inhibitor or insulating oil for industrial transformer generally manufactured from predominantly naphthanic base crude. The base oil used for the manufacturing of transformer oil is 65 NHVI. These oils must with stand large electrical voltage and hence the dielectric strength is important beside these they have excellent low temperature properties (pour point) and have low to medium viscosity index. These functions are very important and oil must retain these properties over a long period of time, despite its constant use under electrical tension an in contact with oxygen.

2.1. Important Properties of Transformer Oil

2.1.1. Insulating Medium

The oil should behave as perfect insulation. However there are some polar components or impurities present in it which decreases the properties of the oil. This is measure by dielectric strength. If some current is passes through the oil it is measure by the power dissipation factor which is also called tangent delta.

2.1.2. Cooling Medium

Transformer oil takes heat from the core of the winding tower to the air.

2.1.3. Arc Quenching

Oil acts as the arc quenching medium in the circuit breaker. It should not be break or decomposed or vaporized during quenching.

2.1.4. Freezing Point

The oil should remain in the liquid state at ambient temperature where equipment has been installed. Hence the pour point of the oil depends on the ambient conditions of the region. Normally transformer works at 40oC, so –10oC pour point is suitable for the climatic conditions of Pakistan. In Europe pour point should be –45oC.

2.1.5. Viscosity

Ideally in the lube oil the viscosity should not be change at various temperature but in case of transformer oil it is desirable that the viscosity should decrease at the high temperature to increase the capability of oil to take away the heat hence the good oil have low viscosity index.


2.2. Production of Transformer Oil

Pak Hy Oil (Pvt.) Ltd. is the only producer of transformer oil in Pakistan. Base oil, which is used, for the production of transformer oil is 65 NHVI. National Refinery Limited supplies base oil. In PHOL this base oil is further treated with clay to improve its color and to remove polar components if necessary. Removal of polar components, make it highly insulated, which is desirable for its application in the electrical devices.

Dark color of the oil is due to the presence of aromatics and other impurities. Various mineral clays, earths and artificial mineral could be used for the color improvement. In PHOL bentonite clay is used for color improvement of oil. This clay is available in the market with the name of Floridin. All additives are added in the storage tank of the base oil.

The stages which are involved in the production of transformer oil are discussed below: 

2.2.1. Mixing or Contacting 

In most simple arrangement for batch operation is the agitated vessel. The system consists of conical bottom agitator vessel equipped with a steam coil and having connection for air use for agitation. Air is injected through the nozzle of the pipe. Circulation of oil is done by means of pump.

The base oil 65 NHVI is preheated at a temperature of 60C through steam heated coils by means of centrifugal pump. After preheating clay is added to oil in predetermined proportion. Mixing or contacting is started with agitation through air, which is supplied by the compressor at the pressure of 16.7psig. This agitation is continued for 20 to 30 minutes. This process removes coloring material completely and polar impurities. After completion this fluid is drain to settling tank for the separation of clay. This batch operation is continued for 2 to 3 hours.

2.2.2. Settling or Separation

This operation is a sedimentation operation in which the separation depends only on differences in the densities of the two separating species and is independent of the particle size. This method is also called heavy fluid separation.

Sufficient time 2 to 3 hours is provided to allow the clay to settle down and separated by drain off the sludge from bottom. Oil is then passed through filter press to separate the suspended particles of clay.

2.2.3. Filter Press

Suspended clay particles in the oil are usually in a finely divided condition. So, the major use of the filter press is to remove finely divided clay from treated cylinder stock.

Filter press which is using in transformer oil is Sweet-land filter press, which consist of number of plates in a series of chambers in which solid may collect. These plates are covered with filter medium i.e. cloth filter of mesh size 15 micron. Slurry is admitted to each compartment under pressure through cloth filter and out through discharge pipe leaving a cake of soil behind.

Clay after treatment could be regenerated, by burning into the kiln.

2.2.4. Pre-heating

After the removal of fine clay particles from base oil, it is pumped into preheater where oil is preheated by steam coils at a temperature of 600C. Recirculation of oil is carried out until the temperature reaches up to 600C. This heating is continued for 20 to 30 minutes.

2.2.5. Dehydration and Filtration Unit 

This is final stage for the purification of transformer oil. Dehydration and filtration process is done under the vacuum to avoid deterioration of oil. Vacuum is also separate moisture from oil. Dehydration and degassing is done in the closed cylindrical chamber having too hot rolls, where oil is heated and the oil temperature reaches at 800C.Oil is circulated in the chamber by means of pump. When oil is drooped on the hot cylinder, its surface area is increased and moisture is easily separated. Moisture and gases is removed from the chamber through vacuum suction. In dehydration and degassing chamber pressure is maintained at 735mmHg. Simultaneously oil is passed through the filter press for fine separation of size 3 micron. After dehydration and filtration process transformer oil is stored in the storage tanks having arrangement of silica gel to control moisture content.

Transformer oil is very sensitive oil. So, its filling is done under controlled conditions. Drums are filled with inert gas such as nitrogen to avoid direct exposure of oil to the atmosphere during filling operation.

AIR-BLOWN ASPHALT

3. Asphalt Blowing 

Asphalted materials are produced by the Vacuum distillation. Asphalt is defined by ASTM as a dark brown to black cementations materials in which the predominating constituents are bitumen’s that occur in nature are obtained in processing. Asphalt contains very high molecular weight hydrocarbon called asphalting and soluble in carbon disulphide, and aromatics and chlorinated hydrocarbon.

Asphalt use for carpeting of airport runway, roads and different grades of asphalt is used for coating, roofing, sealing etc. Cold application of asphalt is also possible in the form of emulsions, which have 30% water with additives act as the binders such as rubber base binder and asphalted primers.

Properties of asphalt like viscosity, penetration and softening point determines the quality and the temperature for use and application.

Penetration with temperature is the ability of asphalt to with stand with the loading and shocks. Ductility measures the elongation or stretch suitable for paving purpose and ability to resist vibrations.

3.1. Sources of Asphalt 

Asphalt can be found from variety of sources some of them are listed below but most of the asphalt produced from Refinancing of Petroleum.

1. Native Asphalt 
2. Rock Asphalt 
3. Lake Asphalt 
4. Petroleum Asphalt 

Here I will discuss only petroleum asphalt in detail.

3.1.1. Petroleum Asphalt

It is produced from Refining of crude oil. They are generally characterized into:

• Paving asphalt 
• Roofing asphalt 

3.1.1.1. Paving Asphalt:

It includes asphalt paving cements, cutback asphalt, asphalt emulsion and HMA (asphalt men and mineral aggregate). Used for pavement coating.

3.1.1.2. Roofing Asphalt:

It is used for roof coatings. Four types are combining called roofing asphalt. Following are three major grades (types) of asphalt used for roofing.

Type 1 

Often referred to as “Dead level” has a low softening point and is used on surfaces.

Type 2 & 3

Typically used on roofs having thickness of 0.5-1.5 and 1-3 inches per foot.

Type 4 

Hard asphalt having high softening point produced by “Air blowing”.

3.2. Uses of Petroleum Asphalt

1. Road Oils 
2. Asphalt Cement 
3. Roofing and Water Proofing 
4. Asphalt tape for Coating 
5. Pipe Sealing and Coating 
6. Molding Compounds 

3.3. Air-Blowing of Asphalt 

All or some of the asphalt product from the de-asphalter may be processed in an air-blowing process to produce what is known as air-blown or oxidized asphalt.

An air-blowing process consists of using an air compressor to blow air through the liquid asphalt at a temperature ranging from 235 to 290°C and being careful to avoid any combustion of the asphalt by remaining about 25°C below the flash point of the feedstock asphalt. In brief, the asphalt fed into an air-blowing process is oxidized by the oxygen in the air. The three most important operating variables in the asphalt air-blowing process are the rate of air injection, the system temperature and the amount of time that the asphalt is kept in contact with the air.

The air-blown product asphalt has a higher temperature softening point than asphalt which has not been air-blown and that is a desirable property for certain uses of petroleum asphalt.

Phosphorous sesqui sulfide, phosphorous pentasulfide and ferric chloride (FeCl3) are known asphalt air-blowing catalysts. Since the process of air-blowing is energy intensive and the catalysts can be expensive, it would be highly desirable to have an air-blowing catalyst which can be used in lower concentration than, for example, ferric chloride and/or exhibit an increased penetration point for a given softening point.

3.4. Processing

Raw asphalt of penetration 80-100 mm/10 is stored in the storage tank at the temperature of 1000C. This temperature is maintained through the heating coil having steam at the bottom of the tank.

Raw asphalt for air blowing is pumped in to the reactor still through the annulus pipe having steam in the shell. Temperature of the steam is 1300C and pressure of the steam is 210psig. The flow of steam and asphalt is counter current for maximum heat transfer. Pipe is insulated with the fiber glass to minimize heat losses.

The reactor still having the working capacity of 22-24 tons is filled with asphalt up to the level of 6800mm or 5.5 ft. The half lower portion of the reactor still is in the furnace and the upper half portion is insulated. To start heating burner is fired and the flame is gradually increased with the filling of asphalt for better start up. As the temperature reaches 2000C, catalyst ferric chloride is added. Ferric chloride acts as dispersant and increases the oxidative susceptibility. Above 2300C air blower is on to pass air to asphalt. As the air passes over the asphalt, oxidation increases. Due to the air blowing exothermic reactions starts and temperature rises suddenly. To control the temperature furnace is off and steam is start, steam acts as jacket. Steam is sprayed inside the reactor still to drop the temperature, temperature that suddenly increases due to exothermic reaction and to avoid the flash. Steam covers the vapors of material. If steam is not sprayed, flash could be occurred in the reactor still. This procedure prevents the cracking or decomposition of asphalt. During this process temperature remains in the limit of 200-2600C. The air is blown through the perforated pipe having the holes of 1/8 inch. The pressure of air is around 197 psig when the temperature is start falling the furnace is fired again. This process is continues for 30-50 hours to reduce the penetration to 5-20mm/10.

During the process samples are taken with certain interval of time from the sampling valve, to check the penetration and softening.

There are three lines for asphalt.

1. Feed Line 
2. Draw Back Line 
3. Product Line 

The drawback line is used to return the asphalt in case of overflow. In reactor there are three ways to control the temperature.

1) Through Steam
2) Through Gates of Furnace
3) Through Circulation of Asphalt

During the process, it is necessary to remove the light diesel oil (LDO), which is removed during air blowing. LDO which acts as impurity and causes to keep the softening point low. The vapors and gases produce during the air blowing are pass through the knockout to separate steam and then struck off with the water for the environmental protection.

To increase the mechanical properties like hardness,, filler earth is added in the pre- determined proportion (25-35% ). Filler is a slate powder. It decreases brittleness and increases ductility. Mixing is done in the tank having impeller of 25 inch diameter at 100 rpm. Temperature of mixing is about 2300-2500C. When the filler is being mixed thoroughly with asphalt, asphalt is ready for filling in drums. To keep the product asphalt in molten form in pipe, oil jacked pipe is being used.

MEMBRANE 

4. MEMBRANE

Membranes have gained an important place in Chemical technology and are being used increasingly in a broad range of applications. The key property that is exploited in every application is the ability of a membrane to control the permeation of a chemical species in contact with it. In packaging applications, the goal is usually to prevent permeation completely.

Pak Hy-Oils being the leading products of industrial grades of Asphalts in the country, having the infrastructure facilities and expertise, had selected to manufacture the modified bituminous membrane locally for water proofing, damp proofing of civil structures, buildings, godowns and canal lining.

The membrane manufactured by PHOL, under the name of Hy-Grip, based upon bitumen and polyolefin sure environment friendly, possess no health hazard, and are recyclable. These membranes are safe enough that they can be lined up with drinking water reservoirs.

4.1. Advantages of water proofing membrane

Its application is so easy that can applied on all kind of surfaces such as parapet returns, chimney grounds and dilatation parts.

It can be applied easily without giving any scraps.

Saving of time and workmanship.

While being stretching constant high, it is resistive for earth’s crust movements and expansion differences.

It doesn’t require any repair or maintenance and it is durable with lifetime of building.

It is not damaged by atmospheric conditions and structural chemicals.

Material usage amount can be estimated beforehand.

Polyester felt brings in high stretching and breakage resistance.

Membrane rolls mustn’t be exposed to sun lights, instantaneous heat exchanges and they must be stored in closed and dark places

They must be stocked with upright position.

There mustn’t be stocked on the top of the other and put heavy loading on the rolls

The rolls must be carried on upright position


4.2. Hy-Grip Membrane Product Range

Hy-Grip bituminous membranes are manufactured to the highest level of international quality standards and are offered for a variety of applications. Hy-Grip membranes are manufactured for roofs, re-roofing, accessible and non-accessible roofs, car parking decks, and a variety of other applications both in the domestic and industrial sectors.

4.3. Membrane Additives

In the manufacturing of membrane, APP (Atectic Poly propylene), IPP (Isotectic Poly Propylene) and slate powder are added in predetermined proportion. These additives give the binding properties and adhesion properties to the membrane and also protect the surface from corrosion with, which the membrane is coated. The flexibility of membranes is maintained at temperature as low as –15oC for APP and IPP.

The dimensional stability, tensile strength and flexibility that are required to cope with the stresses in the modern lightweight roof can only be achieved through these.

4.4. Types of Membrane

The PHOL produce different types of membrane, depending upon their thickness, final coats, application procedures and the field of applications.

There are two types of membrane

1. Plastomat (APP modified Bituminous Membrane) 
2. Elastomat ( Self Adhesive Reinforced Membrane) 

Plastomat Elastomat

4.4.1. Plastomat

It is a torch bonding, flexible water proofing sheet membrane that consists of a very strong non-woven polyester reinforcement, coated on both sides with APP modified bitumen compound. The upper and lower surface is covered with polythene film and is also available in a variety of surface finishes for both covered and exposed application. The lower surface is covered with torch able polyethylene film.

4.4.1.1. Field of Applications:

These membranes are designed for water proofing of flat, low slope concrete roofs, flour slabs, foundation, basements, retaining, walls, reservoirs, pre fabricated concentrate decks, tunnels, tanking works, sewerage tank linings etc.

4.4.2. Elastomat

It is self adhesive, water proofing sheet membranes that consist of a non-woven-polyester, coated on both sides with an elastomeric bitumen compound. The upper surface is covered with polyethylene film and the lower surface is fully covered with silconized release paper to protect the adhesive side of the rolls during storage and is removed just prior to application.

4.4.2.1. Field of Application:

These are designed for water proofing concrete and masonry structures. Application includes water proofing of floor, slabs, foundations, basement retaining walls, tanking shower rooms, kitchens, planters, underground pipes and earth shattered structures etc.

4.5. Membrane Processing 

The asphalt from storage tank is introduced into a mixer, which is jacketed with oil coils and a centrally located impeller which is rotated by a motor. The temperature of the oil is 200oC. The additives APP (Atectic Poly Propylene) and IPP (Isotectic Poly Propylene) are added from the top of the mixer. Here mixing process is carried out and the material is introduced into another mixer. In this mixer slate powder is added in asphalt and proper mixing is carried out.

Mixing of APP and IPP In Asphalt

The asphalt is introduced into TCP (Top Coating Pan). The temperature of the asphalt is 160oC in pan. The level of asphalt is maintained at a particular point in the pan. Before the pan, a roll of polyester sheet is present. The polyester sheet after passing through a series of moving paddles is dipped in the asphalt by means of dipping paddle. Than the polyester sheet passes through two blades parallel to each other and which are used to adjust thickness of membrane.

In the top coating pan, the asphalt is coated on the both sides of the sheet and the excess amount of asphalt which is coated on the sheet is passed through two paddles parallel to each other. Here the polyethylene film is coated at the lower and upper surface of the asphalt coated sheet for Plastomat membrane. For Elastomat membrane siliconized released paper is coated at the lower surface and polythene is coated at the lower surface and the polythene film at the upper surface.

The prepared membrane is then pasd through sea series of hollow cylinder in which chilled water circulates at a temperature of 4oC. The chilled water is supplied by chilling unit which is introduced at one side of the cylinder and comes out through the other side by means of pump. As the membrane passes through these cylinders its temperature gradually decreases. The membrane is then passed through a series of moving paddles and finally it goes for cutting, soiling and packaging. These processes are carried out by automatic machines.

4.6. Application Fields 

Water and stream insulation of wet volumes

Terrace and acclivitous roofings

Pressured underground water applications

Retaining and basement walls applications

Rain streams, balconies, green houses, concrete canalets, garden terraces, water tanks, ponds, dirty water purification applications, car parks and hidden stream applications

As second layer for the dome and vaults type of roofings

As second layer for the hidden stream insulations

As second layer for the chimney grounds insulations

The grounds and walls of Fundamentals

The terraces and wet volumes

The roof tiles and on the wooden roofings

The water tanks

The pools

Multilayered car parks

LABORATORY TESTING 

5. Important test for lubricating oil

5.1. Flash Point

It is the temperature to which a combustible liquid must be heated to give off sufficient vapors to form momentarily flammable mixture with air when ignited under specific conditions (means the lowest ignition point of the liquid while coming in contact with live flame).

5.1.1. Scope

For the determination of Flash point a defined sample quantity is heated under defined conditions. The flash point is reached at lowest temperature at which the application of defined test flame causes the vapors above the surface to ignite.

For the determination of flash point closed and open cups are used. The closed cup method is mainly used for lubricants with a flash point > 79’C.

The Flash point is a very important characteristic for classification of products according to the international transport regulations.

5.2. Pour Point

It is the lowest temperature at which the oil shows movement in the test jar while examined under prescribed condition (means that, it is the temperature after which the oil will not show any movement in the test jar when testing under prescribed conditions).

5.2.1. Scope

The pour point is the lowest temperature at which oil still flows. A sample is systematically cooled and its flowing properties are tested every 3’C. The pour point and the boundary viscosity define the lowest temperature at which oil can normally be used.

5.3. Viscosity Index

It is an arbitrary scale used to measure a fluid’s change of viscosity with temperature.

5.3.1. Scope 

This method describes a procedure for the determination of kinematics viscosity of liquid petroleum products both transparent and opaque by measuring time for a volume of liquid to flow under gravity through a calibrated, glass viscometer. Dynamic viscosity can be obtained by multiplying the measured kinematics viscosity by the density of liquid. Method is intended for application to liquids for which, the ratio of shear stress to shear rate is the same for different viscometer (Newtonian Flow).

5.4. Density and Specific Gravity of Crude Products Test

Specific gravity is the ratio of the mass of given volume of liquid at given temperature, to the mass of equal volume of pure water at the same temperature.

5.4.1. Scope 

This method covers the laboratory determination using glass hydrometer, density, or specific gravity, or API gravity of crude petroleum products or mixture of petroleum and non-petroleum products normally handled as liquids.

5.5. Total Base Number (T.B.N)

It is the method that covers the determination of basic constituents in petroleum products by titration with perchloric acid in glacial acetic acid. The quantity of perchloric acid express as the term of the equivalant of milligrams of potassium hydroxide, that is required to neutralized all basic constituents present in 1 gm of sample.

5.5.1. Scope 

This method is intended for the determination of acidic or basic constituents in petroleum products and lubricants soluble or nearly soluble in mixtures of toluene and isopropyl alcohol. It is applicable for the determination of acids or bases whose dissociation constants in water are larger than 10-9, extremely weak acids or bases whose dissociation constant are smaller than 10-9, do not interfere, salts react. If there hydrolysis constant are larger than 10-9. This method may be used to indicate relative changes that occur in oil during used under oxidizing conditions.

6. Important test for transformer oil 

6.1. Dielectric Strength

Is test gives a measure of the electrical insulating properties of the oils.

6.1.1. Procedure 
Continually increasing alternating voltage is applied to the sample under specified conditions, either until the sample break down or until the sample with stand a defined voltage for a limited time.

6.2. Tangent Delta Test 

Tangent delta test machine determines the amount of the polar coordinates present in the transformer oil. This test is only specified for the transformer oil. Tangent delta is actually the combination of the Whetstone Bridge and Califoster circuit. It measures the resistance across the oil when current at the certain voltage is passed through it.

6.2.1. Procedure

A known amount of sample is taken in the tangent delta’s cell having the electrodes of the path length of 2mm. The temperature is maintained at the 90oC the voltage of the 1kv is applied across the sample and note down the reading by adjusting the sensitivity knobs. This gives directly the reading of transformer oil present in the cell.

6.3. Moisture Content

Kallfisher titration is done in the computerized programmable equipment to determine the moisture content of the transformer oil.

6.3.1. Procedure
The density of the given oil is fed in the program and then the sample is injected through micropipette. The chemicals of the Kallfisher is titrate the water and gives the result.

7. Important test for asphalt 

7.1. Penetration of Bituminous Material

It is the measurement of the penetrating of the specified needle with a weight of 100g for 5 second as the 1/10th of the millimeter at 25°C under controlled specified condition.

7.1.1. Procedure 
Heat the sample up to temperature about 130°C from softening point. Fill the sample in a container that would already be cleaned and dust free. Stir the sample with a stirring rod while it is being heated to remove the air bubble.

Put the sample for cooling at room temperature. Take of any gel formation on the sample while cooling. After attaining the room temperature put the sample cooling bath for 60 minutes. Put under the penetrometer align the needle and remove the parallax released the spindle by pushing the thumb for 5 second and remove the thumb to stop the spindle. Push the penetration dial to check the penetration.

7.2. ASTM D36 Softening Point

This method is intended for the determination of the softening point of Bitumen

Softening Point: The temperature at which a substance attains a particular degree of softness under specified condition of test.

Softening point of the substance could be determined by the ASTM D36 (A ring ball method).

7.3. Volatile Matter 

7.3.1. Procedure 

Weigh to the nearest milligram between 1 and 2 gram of the primer into a tarred flat bottomed circular dish, about 75 mm in diameter. Heat the dish and it contents in an oven at the temperature for 3 hr. allow the dish to cool to room temperature in a desiccators and reweigh to the nearest milligram.

7.4. Specific Gravity at 25oC 

7.4.1. Procedure
Heat about 100g of sample slowly in the melting pot to between 60°C to 70°C above the softening point. Until the sample is completely fluid stir continuously to avoid local overheating. Pour the fluid into the mould avoiding the inclusion of air bubbles. Allow the mould and the material to cool up to the room temperature. Suspend the molded specimen from the hook on a balance using a suitable length of nylon thread and weigh it to the nearest milligram. Place the beaker fill with water at 25°C. Place the beaker on the bridge across the balance pan. Suspend the molded specimen from the hook on the balance so that is fully immersed in the water in the beaker about 25mm from the bottom of the beaker. Carefully remove all air bubbles adhering to the specimen and the tread. Weigh the specimen into the water to the nearest milligram.

CONCLUSION: 

The following report covered the methods of production and testing of lubricating oil, transformer oil, asphalt air-blowing and asphaltic membrane.

It provided the information about lubricating oil, its properties, composition, functions and most importantly that how it is manufactured in industries through blending with additives. The lubricating oil section also provided the basic functions of different additives used in lub oil manufacturing. It also described the lube blending process in which blending is done by three ways i.e. by passing air through the kettle, by an agitator and by circulation of oil.

The report also covered the basic information about transformer oil, its uses and properties of oil. It described the method of production and testing of transformer oil. The stages involved in production process are mixing, settling, separation, filter press, and dehydration or filtration unit to the storage and packaging. Generally few tests have been done for the assurance of desired quality of oil which are dielectric test, tangent delta test, and moisture content.

The air blowing of asphalt have been discussed also which consist of mainly three important operating stages in the asphalt air-blowing process are the rate of air injection, the system temperature and the amount of time that the asphalt is kept in contact with the air. Phosphorous sesquisulfide, phosphorous pentasulfide and ferric chloride (FeCl3) are known asphalt air-blowing catalysts. Test which have been used for asphalt quality are softening point, penetration and volatile matter presence.

The last portion is about the modified bituminous membrane locally used for water proofing, damp proofing of civil structures, buildings, and canal lining. Plastomat and elastomate are the two types of membrane. the asphalt is coated on the both sides of the sheet and the excess amount of asphalt which is coated on the sheet is passed through two paddles parallel to each other. Here the polyethylene film is coated at the lower and upper surface of the asphalt coated sheet for Plastomat membrane. For Elastomat membrane siliconized released paper is coated at the lower surface and polythene is coated at the lower surface and the polythene film at the upper surface. The membrane passes through series of chilled hollow cylinders and its temperature gradually decreases. The prepared membrane is then sent for finishing.

The report concluded on laboratory testing of lubricating oil sample carried out in industry which includes its pour point, viscosity index, specific gravity and flash point.

Nomenclature

• PHOL Pak Hy-Oil ltd 
• API American Petroleum Institute 
• ASTM American Society for Testing and Materials 
• SAE Society of Automotive Engineers 
• NHVI Number High Viscosity Index 
• MVI Medium Viscosity Index 
• BSHVI Base Stock High Viscosity Index 
• ISO International Standards Organization