Outdoor transformer installations
The concern for fire hazards here is reduced because of the outdoor location; however, the hazard is not eliminated, and you must take the following precautions.
Less-flammable liquid-insulated transformers. The requirements for these installations can be found in Sec. 450-23. Transformers meeting the less-flammable class requirements can be installed outdoors attached to, adjacent to, or on the roof of Type I and Type II buildings, as shown in Fig. 3. (Type I and II building constructions are classified as noncombustible construction and can be further investigated in NFPA/ANS1220-1995, Types of Building Construction. Local building codes such as BOCA, ICBO, SBCCI, etc. also may influence the determination of building construction type.)
Less-flammable liquid-insulated transformers have requirements for additional safeguards if they are installed outdoors on, attached, or adjacent to buildings not meeting Type I or Type II constructions, or if they are adjacent to combustible materials. These additional safeguards are not clearly spelled out in the NEC, but some guidance is given. You should discuss this with the local authority having jurisdiction. Fire barriers, space separation, and compliance with the liquid listing requirements are all recognized safeguards in the NEC.
Fire barriers generally consist of 1-hr fire-rated materials and may be one-, two-, three-, or four-sided, depending upon the arrangements of the transformer to the occupancy. [ILLUSTRATION FOR FIGURE 4 OMITTED].
Space separation, as shown in Fig. 5, is a requirement based on the relative separation of the transformer from the building or combustible materials. To determine the proper space separation, you have to evaluate the amount of liquid and its particular heat-producing characteristics. Factor Mutual (FM) has performed such evaluations and provides recommended clearances for the various types of transformers.
Compliance with the liquid listing requirements: Basic details regarding the listing agency requirements are discussed later.
The NEC also requires that similar safeguards to the ones discussed above be taken if the transformer is located adjacent to fire escapes or door/window openings. The intent with this precaution is to ensure that adequate means of egress from the building is provided if the transformer is in a failure mode.
Sec. 450-24 covers this class of transformer for outdoors installations as well. No special requirements exist for these transformers installed outdoors. They must be designed and constructed to absorb any gases generated by arcing inside the tank, or the pressure relief vent must be vented to an environmentally safe area.
Oil-insulated transformers. Sec. 450-27 of the NEC is specifically dedicated to these transformers installed outdoors. The NEC does not provide any special requirements for these transformers if they are installed adjacent to, attached to, or on the roof of a building of noncombustible construction (except when installed close to doors, windows, or means of egress). However, good engineering judgment should be used when installing in these locations.
Oil-filled transformers can have failures resulting in a transformer fire, and the potential impact of that fire on the building should be evaluated. The heat convection and radiation rates of the oil should be reviewed and compared with the ability of the building construction to handle the heat released during a fire. Some guidance to this type of evaluation is provided in the "Listing Requirements" section of this article, on page 80. Also, you should reference IEEE 979-1992, Guide For Substation Fire Protection.
Additional information can be obtained from insurers for guidance. FM, for instance, gives a number of reasonable guidelines for these transformers where they are installed adjacent to a building.
For other situations, the NEC requires that "combustible materials, combustible buildings, parts of buildings, fire escapes, and door and window openings shall be safeguarded from fires originating in oil-insulated transformers installed on roofs, attached to, or adjacent to a building or combustible material."
The recognized safeguards, as shown in Fig. 6 (on page 79), are space separations, fire-resistant barriers, automatic water spray systems, and enclosures that confine the oil of a ruptured tank.
(by Loyd, Richard E)
to be continue...
Indoor transformer installations
Transformers installed interior to a building require special consideration for their placement because of the potential hazard should a catastrophic failure occur. The objective of the following rules is the practical safeguarding of people and property.
Less-flammable liquid-insulated transformers. The specific NEC requirements for these transformers can be found in Sec. 450-23. Transformers qualifying for placement in this category must contain a liquid with a fire point not less than 300 [degrees] C. The flow chart in Fig. 1 (on page 75) describes an overview of the requirements for this section.
Nonflammable fluid-insulated transformers.The specific NEC requirements for these transformers can be found in Sec. 450-24. Transformers in this class must have a nonflammable dielectric fluid that does not have a flash or fire point and is not flammable in air. The flow chart in Fig. 2 describes the requirements for this section.
Askarel-insulated transformers. NEC requirements for these transformers can be found in Sec. 450-25. Transformers in this class are insulated with Askarel fluid. If the transformer is rated over 25 kVA, it must be provided with a pressure-relief vent. If installed in a poorly ventilated area, the transformer must be provided with a method to absorb any gases generated by arcing inside the case, or the pressure relief vent must be vented to the outside of the building.
As with less- and non flammable liquid-filled transformers, those filled with Askarel are not required to be installed in a vault unless rated greater than 35kV. The requirements in this section have remained unchanged for many years, since no new installations have been made in recent years.
Oil-insulated transformers. The specific NEC requirements for these transformers can be found in Sec. 450-26. In general, these transformers always must be installed in a vault. Exceptions to the vault requirements are as follows.
* If the total transformer capacity is 112 1/2kVA or less, the vault may be constructed of 4-in. reinforced concrete.
* If the nominal voltage is 600V or less, the vault may be omitted if arrangements are made to prevent a transformer oil fire from igniting other materials, and the total transformer capacity does not exceed 10kVA in a section of a building classified as combustible or 75kVA in a section of a building classified as fire-resistant construction.
* Electric furnace transformers can be installed without a vault where the total rating does not exceed 75kVA, and arrangements are made to prevent a transformer oil fire from igniting other materials. These transformers are very specific to applications involving electric furnaces, and since many precautions must be taken for the electric furnace itself, the vault requirement is relaxed.
* Transformers are permitted to be installed in a detached building that does not comply with the vault requirements if neither the building nor its contents presents a fire hazard to any other building or property, and if the building is used only in supplying electric service, and the interior is accessible only to qualified persons.
* The vault may be omitted for transformers used in portable and mobile mining equipment with additional conditions specified.
(by Loyd, Richard E)
to be continue...
Knowing NEC, NESC, insurer, and listing agency installation requirements will help you select the best type of insulating medium for the application.
Increasing concerns over fire safety in and around buildings can result in questions about transformer installations, specifically for liquid-filled transformers. Also, installation requirements per the National Electrical Code (NEC) and the National Electrical Safety Code (NESC) as well as insurer and listing requirements can influence your decision as to the type of transformer specified. The following will answer these questions and help you make informed decisions.
A variety of requirements may be applied to a transformer installation, but each one must be considered for the application. We'll focus our attention on the following:
* The NEC (1993 and 1996 editions), which is generally enforced by local authorities responsible for building and/or electrical codes;
* Listing requirements, which are based on third-party evaluation of the transformer or components and are specific to the product and manufacturer;
* Insurer requirements, since the failure of a transformer can result in property damage, loss of life, and loss of revenue (due to downtime) for the business affected by the failure; and
* Local amendments, which the local code enforcing body may have adopted, additional requirements above and beyond the basic installation Code.
Transformer installation requirements in the 1993 NEC
In order to evaluate the specifics of NEC requirements on transformer installations, you should review the requirements for each transformer type. To show the differing requirements related to various transformer types, we'll cover the specifics for less-flammable liquid-, non flammable liquid-, Askarel-, and oil-filled transformers.
Vaults. In determining the type and location of a transformer in a design, the requirement to have a transformer vault plays a key role in the cost and safety of an indoor installation. The expected construction costs and space impacts of a vault must be considered before selecting the particular transformer to use. So that you can understand the magnitude of the vault issue, the following requirements for transformer vaults are summarized from Part C of Article 450 in the NEC.
Walls, roofs, and floors shall be constructed of materials providing a minimum fire resistance rating of 3 hrs. Typical of this rating is 6-in.-thick reinforced concrete.
Floors in contact with the earth shall be 4-in.-thick concrete minimum. If located with space below, the floor shall have structural strength for the expected load and have a fire resistance rating of 3 hrs.
Doorways leading to the interior of a building from the vault shall have a 3-hr construction. A door sill or curb must be provided that will confine the oil from the largest transformer within the vault. Minimum sill height is 4 in.
Doors shall be equipped with locks and accessible only to qualified personnel. Doors shall swing out and be equipped with panic bars, pressure plates, or other devices that are normally latched.
Ventilation (per specifics in Sec. 450-45): The vault must be ventilated to remove the heat generated by the transformers during operation so as not to create a temperature rise beyond the transformer rating.
Drainage: Vaults containing more than 100kVA of transformer capacity shall be provided with a drain or other means that will carry off any accumulation of oil or water in the vault unless local conditions make this impracticable. The floor shall be pitched to the drain where provided.
Note: If the transformer is protected with an automatic sprinkler, water spray, carbon dioxide, or halon, the entire vault construction is permitted to be of a 1-hr rating.
As you can see, there's a substantial investment in construction costs and physical space when a transformer vault is needed. However, by utilizing the following additional safeguards, a vault may not be necessary.
(by Loyd, Richard E)
to be continue...
7. Precision Top-Ups and Drain and Fills
Once the bulk storage system is properly set up, one should consider the method for transporting oil and filling machines. The best top-up method utilizes a proper top-up container, one that is sealed from the environment, has a built in spout, hand pump, etc. If short cuts are taken at this stage, all of the time and effort spent building and designing the bulk storage system and ensuring the quality of the bulk oil with filtration will have been wasted. Too many times oil is highly contaminated from the time it is dispensed into the top-up container to the time it is added to the machine.
Using washable and re-usable top-up containers allow for easy cleaning and maintenance. Typically, non-sealable top-up containers that are re-used introduce large amounts of containments to the system, which could counteract any effort of removing or excluding contaminants, and also can have a slight lubricant cross-contamination effect.
For top-ups of larger sump volumes, such as large gearboxes, circulating system reservoirs, etc., the use of filter carts is the preferred method for transferring the new oil from the storage container to the machine.
8. Proper Top-Up Container and Grease Gun Storage
Storage for top-up containers, grease guns, rags, etc., is another important step to ensure contaminants are not introduced to the lubricants as a result of poor housekeeping. These tools should have their own dedicated fire-proof storage cabinets for easy access and organization.
Grease storage is simpler than oil storage but also must not go overlooked. Open grease tubes and drums are magnets for attracting airborne contaminants such as lint and dust. Securing used grease tubes that will be re-used in sealable washable containers is considered the best practice. The containers will hold one tube of grease and allow for great contaminant exclusion. Used drums of grease are at an even higher risk of contamination. These drums are often opened and used over a greater period of time, leading to more and more opportunities for contaminants to enter. If not using a sealed air style grease dispensing unit for drums of grease to fill grease guns, some of the best methods for contaminant exclusion are to use Velcro style covers or snap-on caps. Using these types of contaminant exclusion devices will keep the grease cleaner and prolong its life.
Grease guns should be stored in a clean, dry and controlled environment. They are precision tools that must be taken care of in order for them to provide the maximum degree of accuracy and reliability. Grease guns should be regularly cleaned and inspected for proper function and an annual calibration should be performed. This calibration will ensure the same volume of grease is still being dispensed with one shot as when the gun was new. The best method for grease gun calibration is to use a postal scale to measure how much grease is dispensed with one pump.
Lubrication tools should be stored in a fire-proof storage cabinet for easy access and organization.
(by Stephen Sumerlin)
to be continue...
3. New Oil Receiving
Oftentimes, improper receiving techniques do nothing but promote higher risks of contamination ingression, mixing of lubricants, etc. Proper written receiving procedures should be in place to ensure the highest level of consistency and cleanliness is maintained. Proper receiving techniques should include filtration of incoming oils. Many times new oils may be dirtier than your defined particle target cleanliness level. Meaning, if you define your particle target cleanliness level and spend time, money, manpower, etc., to achieve these levels of in-service lubricant cleanliness, the last thing you want to do is contaminate it with “dirty” new oils. 4. Quality Control
Quality control of lubricants delivered from lube suppliers must be verified to ensure the correct product is being delivered and that the cleanliness of the delivered lubricant are up to current target particle and moisture cleanliness levels.
To help ensure your lubricants are meeting their standards, the use of oil analysis is a powerful tool and will reveal the following:
- Quality of base stocks
- Additive quality and concentration
- Lubricant performance properties
- Thickener performance properties (grease)
5. Presence of Mixed or Contaminated Lubricants
Oil analysis results and other quality assurance variables, such as damaged containers, rusted containers and any other quality issue, should be well documented and cataloged.
Items to note in the documentation phase are:
- Delivery date and date of oil sample taken
- Inspection results of storage containers
- Labels depicting results of oil analysis test
- Itemized checklist for sampling test
- Periodic decontamination with filtration
Whichever storage container is chosen, it is best to filter the new oil while filling the storage container. Doing so will reduce the amount of contamination that is delivered with the new oil, but periodic filtration and agitation should be performed to maintain certain ISO cleanliness levels and prevent additive settling. Periodic filtration is a good practice to ensure clean, fresh oil will be used to perform top-ups and drain and fills. There are two primary methods for filtration of bulk stored oils: hard plumbed filtration system or filter cart. The hard plumbed filtration system works best in conjunction with a rack mounted system.
Each container should be fitted with a breather, sight glass, filter, lubricant label, quick connect fittings and dedicated dispensing line. This system will help ensure the lubricants are at optimal condition when they are needed and the right product for the application is dispensed.
Periodic filtration for drum storage also is easy with the use of a filter cart once the drums are equipped with quick couplers. No matter how large or small the storage container, periodic decontamination should be a priority to maintain the quality of the stored lubricant. 6. Dispensing Options for Stored Oils
When stored oil is transferred from the bulk storage system to the top-up container, it is best to filter the dispensing oil. This can be made very easy with the use of a hard plumbed filtration system and a rack mounted storage system fitted with dedicated dispensing nozzles. If using 55-gallon drums, they can be fitted with quick connect fittings, a hand pump, an inline filter manifold breather and sight glass to achieve the same goal.
Improper dispensing of new oils into top-up containers is a primary cause of self-induced contamination. Proper techniques and tools must be used to ensure your new, filtered oil is transferred to the top-up container with minimal exposure to atmospheric conditions. Not using proper techniques here could be a waste of time to the filtration efforts, storage and in-service lubriation cleanliness.
(by Stephen Sumerlin)
to be continue...
"Our oil analysis results often show levels of water present in the oil. We are considering the purchase of portable equipment suitable for the removal of water from lube and hydraulic oil systems. I have also been told by some people that some separators can only remove water down to the water saturation level of the oil. Is there a preferred method for removing water from oil in a lube or hydraulic circulating system? How much water can be removed by these methods?"
Water in any lubrication system is bad news. In hydraulic systems, it can result in vaporous pump cavitation, corrosion and valve stiction, while in circulating lube oil systems it can cause oil film strength loss, rusting and other serious mechanical problems.
The effects of water on the oil are often overlooked. Excessive water contamination can result in premature oil oxidation and promote the buildup of sludge and varnish. In ester-based fluids, it can result in the hydrolytic destruction of the base fluid resulting in the formation of corrosive acids. In some circumstances, water can also strip additives from the oil through water washing or hydrolysis resulting in premature oil degradation.
For these reasons, the best strategy when it comes to water is to monitor and control the root cause of the water ingression. This can be achieved by ensuring that all seal and breathers are in good shape (consider using desiccant style breathers), lube tank hatches are closed and sealed properly and that top-up oil is stored and handled properly.
Water can exist in three phases in an oil, free, emulsified and dissolved. Free and emulsified water cause the most damage so a good rule of thumb is to keep moisture levels below the saturation point so that all the water is in the dissolved state. For typical mineral-based industrial oils, this is typically 200-300 ppm.
The most effective way of achieving this is to use a vacuum dehydration unit
. These systems are capable of removing free and emulsified water as well as up to 70-80% of the dissolved water. For a typical hydraulic fluid, this can mean water levels as low as 30-50 ppm (0.003-0.005%). Alternatively, many companies are reporting success with vapor extraction devices mounting on tank tops. Some of these devices work similar to air conditioners in removing humid air from tank headspaces.
There are several jobs that the lube oil is designed to perform. Lubrication of moving parts, cooling, cleaning, corrosion control, and etc. The oil companies work diligently to produce oils to meet engine manufacture's ever increasing requirements, creating better and better oils each year. Over the years, using vastly improved oils, the engine manufacture's have increased their recommended oil drain intervals for their engines, but we are still draining the oil on a routine basis. When most maintenance personnel are asked, "why does one have to change the oil?" Their answer is usually one of the following: "Because it breaks down" or " Because it wears out."
The concept that oil "breaks down" or "wears out" is not correct. Just look at what has happened over the past fifteen years, in regards to oil drain intervals. Fifteen years ago, typical recommended oil drain intervals for a 300 horsepower H.D. diesel was around 8,000 to 10,000 miles in an over the road truck. Today, the same trucks typically have 425 to 450 horsepower engines, yet the oil drain intervals have increased to 15,000 to 25,000 miles. The same quality crude oil base stocks that were used 15 years ago are used to make oils of today. So why does the same oil today last twice as long as it did fifteen years ago? The answer can be found within the additive package of today's oil. The petroleum base of oil lube does not wear out, rather it is the additives within the oil that become depleted, due to the presence of contamination. Therefore, it makes common and technical sense that if one could remove these contaminants, we could then run the oil for a longer period of time, but for how long?
New Engines - New Problem:
One of the major contaminants facing the new oils of today is Soot contamination. Soot is a four letter word to diesel engines. In recent years engine manufacturers have had to develop engines to meet EPA emission standards. Therefore, contamination that once was "Going Up In Smoke," is remaining in our engines and winding up in the lube oil. These newer engines emit less contamination through the exhaust, therefore higher carbon soot levels are being detected within the engine. Several SAE papers have shown how Soot contributes to diesel engine wear. One of these papers points out just how severe the problem of Soot in today's engines is. According to COMO paper EX1, Soot will enter the lubrication oil at the rate of .0048 oz for every gallon of fuel burned. A truck will burn 1,786 gallons of fuel every 12,500 miles, at 7 mpg. During this 12,500 mile interval, more than half a pound (8.75oz) of Soot will enter the oil.
The majority of Soot particles generated within the engine are 10 microns or SMALLER. Most engines are only equipped with full flow filters that, at best, remove and control particles 15 microns and LARGER. Full flow filters are now designed to protect the engine from large particles that could damage vital parts. These filters must be porous enough to allow high flow rates of oil to the engine for lubrication of parts. The typical flow rate for a full flow filter within a diesel engine is 15 to 20 quarts per minute. Therefore, they are not designed to remove small contamination. Full flow filters do little to control Soot contamination within the oil.
Soot & The Next Millennium:
This problem of Soot contamination in today's engines will soon become a larger problem by the year 2004. EPA emission requirements for the year 2004 will force the diesel industry to deal with a three letter word, EGR (exhaust gas re-circulation). In March 1998, at API's Lubricants Committee meeting in San Francisco , as reported in "Lubes & Greases" magazine (May '98), John Graham of Cummins Engine Co. had the following comments about the impact of EGR on diesel: "Diesel engine manufacturers face the prospect of having to REDUCE their drain interval recommendations significantly because of increasing levels of Soot, caused by the need to introduce EGR." In an effort to reduce nitrogen oxide (NOx) emissions in the year 2004, it will be necessary to incorporate EGR for diesel engines. EGR exhaust is cooled and re-circulated though the engine in order to reduce oxygen concentrations within the cylinder thereby lowering flame temperature and nitrogen oxide (NOx). Soot and fuel sulfur oxides are critical issues with EGR. In his opinion, Graham noted a dramatic decrease in oil change intervals to, say, around 10,000 miles would be needed. Instead of trying to solve this problem of higher Soot levels by adding additional filtration, the engine manufacturers and oil companies are relying on those "NEW" oils to solve this problem and if the oil companies can come up with new oils to contend with EGR Soot, the only option will be to shorten oil drain intervals, or is this the only option?
There is a very common sense approach to the dilemma facing the engine and oil manufacturers. Soot is not a gas or liquid, it is a solid particulate. One can greatly extend present routine lube oil drains by installing additional depth type by-pass filters. The By-Pass Oil Filter only filters about 10% of the oil each minute through a very dense element. It does not supply the engine with oil for the purpose of lubrication. Its sole purpose is to clean the oil. By-Pass filters can control the higher levels of Soot and other solid Contamination within today's engines, as well as ones into the future, without the need to go to a higher tech oil.
Other than Soot , there are several other types of contamination that must be dealt with in order to extend lube oil drains. In order to greatly extend and/or eliminate the process of routine oil drains one must install additional filtration and establish the proper service intervals for these filters to deal with contamination missed by the full-flow filters and other types of contamination generated within the engine.
There are three basic types of contamination that must be dealt with: "Solid", "Moisture" and "Condition Caused" contamination. The following information will fully explain these types of contamination and how additional By-Pass filtration will effectively control these areas.
Soot and Other Solid Contamination: It is generally recognized, backed by numerous tests and studies over the last 40 years, that contamination generated in an engine that is responsible for the majority of "normal" wear, is within the 1 - 15 micron range. Also this small solid contamination contributes to accelerating Condition Caused Contaminants such as Oxidation, Nitration, Acid formation and more. Consequently, it is imperative that this contamination be removed from the system as fast as possible. The typical factory full-flow filter cannot control 1-15 micron particles due its porous design to supply the engine with a high flow rate of oil. One must use UF filtration that is capable of controlling solids in the 1-15 micron ranger and smaller.
Moisture Contamination: Moisture contamination within the lube oil will cause viscosity increase, VI polymer decrease, TBN decrease, acid formation, accelerated sludge formation, and corrosion of parts. To safely eliminate routine oil drains, one must use additional filtration that utilizes an adsorbent filter media which can remove suspended moisture from the lube oil.
Condition Caused Contamination: There are three MAJOR Condition Caused Contaminations that are formed within the lube oil during normal use: Oxidation, Nitration, and Acid. These contaminants are formed when solid and moisture contamination are present, and certain operating conditions exist within the engine. These Condition Caused Contaminants can be controlled by the use of additional filtration and adding new make-up oil at the service of the UF by-pass filter.
There are three basic types of contamination that must be dealt with: “Solid”, “Moisture” and “Condition Caused” Contamination. The following information will fully explain these types of contamination and how adding additional By-Pass filtration will effectively control these areas.
a) Oxidation: Oxidation occurs when the hydrocarbon constituents (and other products) of lube oil combined chemically with oxygen. Lube oil in engines will combine with available oxygen under certain conditions to form a wide variety of oxidation products. Many of these direct or primary oxidation products combine with other materials such as wear metals, solid contamination, and moisture, to form second and third derivative products. As with most chemical reactions, oil oxidation is accelerated by heat and pressure. Heat in particular will speed up the oxidation process. Various studies have shown that lube oxidation (with many variables such as the type lubricant and additive package in the lubricant) that the oxidation rate can be doubled for every 15 to 20 degrees increase over 180 degrees F. Also, engine load, which will dictate the levels of oxygen and pressure within the engine can be seen in the form of accelerated acid formation, corrosion, oil thickening, deposit formation, and accelerated wear.
All top quality lube oils have an additive package that contains oxidation inhibitors to slow the oxidation process and alkaline detergents that will neutralize acids formed by oxidation. Normally these additives will only last a certain length of time before they are depleted and the oil must be drained. GCF, Inc. has established the correct means by which to control oxidation within engines. As we have seen, oxidation is greatly stimulated by the contamination solids and moisture. Solids tend to hold heat, thereby increasing the lube oil temperature around the solid contamination. This condition acts to accelerate oxidation. Combine this effect with the presence of moisture (H2O) from normal condensation, and the oxidation process accelerates even faster. When moisture is present in the lubrication system, the level of oxygen available to mix with hydrocarbons in the lube oil is raised dramatically. The presence of normal solid and moisture contamination, combined with maximum operating load of the equipment, will produce high oil oxidation rates, even with normal oil temperatures. In order to control the oxidation process, the GCF PM Program recommends By-Pass filtration products that can control the levels of moisture, wear metals and other solid contamination. By removing this contamination, the oil will offer a better seal between the rings and liners and therefore reduce the amount of blow-by during the combustion process. Blow-by contributes to the amount of oxygen and moisture within the engine.
Once we have removed the contamination which acts as catalyst to accelerate the oxidation process and have offered a cleaner oil to seal the engine, then we are left with MINIMAL OXIDATION for the additive package of the oil to contend with. The engine will use a certain amount of oil each operating day. Combine this amount of new oil with the amount added at the time the By-Pass Filter is serviced, and the engine will maintain a sufficient amount of active additives to keep oxidation in check indefinitely.
b) Nitration: The combustion chambers of engines provide one of the few environments where there is sufficient heat and pressure to break the atmospheric nitrogen molecule down to two atoms that can react with oxygen to form nitrous oxides (NOx). When nitrogen oxide products enter the lube oil through normal blow-by, they react with moisture present in the lube and become very acidic and rapidly accelerate the oxidation rate of the oil. Proper By-Pass Filters can control the effects of nitration in the same ways it controls oxidation. By delivering cleaner oil to offer as a seal between the ring and liner, blow-by of NOx components are kept to a minimum. Also, the GCF Filter keeps the oil chemically dry and prevents the mixing of NOx and moisture, which controls NOx acid formation and accelerated oxidation of the oil.
c) Acid Formation: Acids are formed within the lube by several sources. We have already covered two of them in the form of acids formed from oxidation and nitration. In most all forms of fuel for internal combustion engines, trace amounts of sulfur are present. Sulfuric acid is formed within the lube oil when sulfur molecules react with oxygen in the combustion chamber to form sulfur oxides. These sulfur oxides are then blown past the rings and enter the oil. Here the sulfur oxides mix with moisture to form the highly corrosive sulfuric acid. It is next to impossible to remove trace amounts of sulfur from fuels by filtration. However, it takes two components to make the sulfuric acid, sulfur oxides and water. By using UF By-Pass filters that utilize absorbent type filter media, such as cellulose (paper) or cotton, the TBN (Total Base Number) of the oil stays up and the TAN (Total Acid Number) remains low.
After taking a look at all of the types of contamination and the effects they can have on an engine if left unchecked, I think that you can now see why the use of UF By-Pass filters is so important. When using these filters, one can remove and control contamination within the engine. Once this contamination is removed from the system, lube oil drain intervals can be greatly extended.
After understand above facts, we recomend our TYA vacuum lube oil purifier machine, which can solve the oil "wear out" problem, it is more economical compare with replacing new lube oil, because oil cost is higher everyday.
To improve transformer oil, insulating oil dielectric strength, making less trace moisture content, gas content, dielectric loss factor and other indicators, before pumping transformer oil into the tank must be preceded by a rigorous treatment, the effective removal of oil in the water, gas and impurities. In practice applications, we have for different types of transformer oil, insulating oil using different forms of oil filter for targeted treatment, results were better.
1. For the general transformer are impurities, water and dust contaminated transformer oil, you can use the JL pressure transformer oil filter, through a series loop filter, is usually able to meet the requirements. Its principle is to use oil filtering paper to absorb moisture, filter impurities. Advantage is a subtle effect of impurity removal is good, its simple structure, convenient maintenance, reliable operation, easy handling, so widely used. The disadvantage is that water filters are not thorough; it only applies to low-voltage level of transformer oil, insulating oil filtration.
2. Now generally used a vacuum oil purifier (there are ZY single stage vacuum transformer oil purifier machine ZYD double stages vacuum transformer oil purifier), it can not only completely remove the oil water and gas, but also can effectively remove small impurities. The process is: when dealing with coarse filtration of transformer oil → → → heating oil fine filtration vacuum degassing → Absolute dehydration. Coarse metal mesh filter and strong magnets, fine filtration is usually 1 ~ μm micro-filter impurities. At present many different types of fine filters, sintered metal powder material, metal microporous materials, ceramic filter media and the use of special structure of filter paper filter core and so on.
Transformer oil heating degassing vacuum dehydration. The principle is that the vacuum inside the tank, the heating of transformer oil with the formation of oil mist spray approach, leaving the oil in the gas and water escape. Oil temperature around 60 ℃ in general, not too high so as to prevent aging of transformer oil. This approach dehydration degassing effect is better, is more commonly used methods.
If the oil is sprayed into the oil has a certain diameter beads, the beads due to higher oil interfacial tension, making the oil water and gas within the beads difficult to bring into full play. To this end, the diameter of injection holes to choose appropriate, and generally taking the time to be in the tank set up with a few baffles the mouth to prevent the transformer oil is pumped vacuum.
At present, foreign and domestic has also adopted a more advanced membrane dehydration degassing method is to make the oil into the tank, through a degassing components formed after the thin oil film, and has always been to film the entire process of degassing state of complete dehydration , thus making the water in oil and gas easier to remove.
3. Badly contaminated transformer oil filter/oil regeneration (Choose our BZ oil regeneration device).Contaminated transformer oil (commonly known as dirty oil), is being mixed with very small impurities and oil molecules combine to form a colloidal contaminated transformer oil, and after years of used transformer oil, the general product release for the repairing of oil (This oil has a very low pH value). Of such waste oil must be used in order to improve the absorption approach to oil targets. Were more commonly used silica (SiO2) or activated alumina (A12O3) as adsorbent. Waste oil processing system in order to ensure full access to silicone and transformer oil, and to facilitate replacement of silica gel, silica gel tank set up in a number of partitions, the silica gel into a small cloth bag within the rotation, not in bulk. After the heating of the transformer oil into the gel tank, do a certain time cycle to its full absorption effect, and then injected into the Absolute through the oil filter tank. In the process should be regularly monitored to determine the absorption effect, when the absorption effect is not apparent that it should consider replacing the silica gel. General silicone oil consumption by weight or about 3% ~ 5%. Waste oil processing system with the new oil-processing systems should be separated to avoid cross-contamination. Loading used waste oil cans, containers, etc. must be thoroughly cleaned before be used for the normal production of the oil system.
The Double-horizontal vacuum evaporation vessels can enlarge evaporation area efficiently. The heater, being places in the vacuum vessels, becomes an evaporator. Thus the evaporation areas of Double-horizontal vacuum vessels are three times more than of the common vacuum vessel. This innovation can dehydrate and degas effectively and separately. This optimal structure of the dehydration (degas) system enlarge the surface area of oil exposed to the vacuum system and extends the flowing distance of the oil in the vacuum system. Thus there has sufficient time to remove the moisture and gas from the oil by vaporization.
The filtering materials with variable apertures are made of specialized glass fiber.the sizaes of the filtering fiber and aperture dwindle gradually in the different filtering stages. The impurities with different particulate sizes are filtered step by step.the capability of removing particulate matters is improved greatly by this method.
The filtering system has stable and perfect filter fineness. The filter fineness has several grades. Including 126.96.36.199.5.6.10. μm etc.
The filtering system is equipped with reverse rinse and filth device.it improves the effectiveness filtering and extends the lifetime of filter awfully
Electrical apparatus controlling system
The main components of the electrical apparatus made by Siemens, Schneider company ensure the safety of the controlling system .having interlocked protective system, pressure protective device which will avoid overload,over voltage,blank pumping,blank heating,oil leak and electricity leak etc.
Oil heating system
The unique effective electric heater structure heats the oil uniformly
Oil heater system assures less than 1.0w/cm2.during the heating process, the deterioration of the oil cuased by overheating is avoided.
The oil temperature can be adjusted between 0℃ to 100℃.the heater is controlled manually or automatically .the heater will stop automatically when the oil temperature reaches a certain degree
Being installed with safety protection devices, the heating system is secure and reliable.the heater will stop operation automatically when the oil volume of inlet is too much to avoid the damages of the heater
Oil-level controlling system
The oil-level floating ball and double-infrared liquid level automatic controller system are installed in the vacuum vessel to control the oil level so as to avoid the oil leaking in the operation.
The new innovation of eliminating forth can avoid the oil ejecting and gushing during the process.
High quality components
The main component parts of our products such as vavuum pump ,oil pump, motor and electric apparatus are from SIEMENS, ABB, SCHNEIDER, LEYBOLD and AMICO etc. They ensure our products high quality and reliability.
Structure and apparatus of oil purifier
Our products adopt ship-shape chasis-mount structure to ensure oil leak proof and protect the environment from pollution.
The whole equipment is characterized by small size.light weight and convenient to move around.various sizes and configurations (alloy shield) available
Vailable in mobile or stationary options
Automatic vacuum oil purifier or anti-explosion vacuum oil purifier is both available according to customers' need.
Cooler, medium condenser system
The system is composed of cooler .condenser,water receiver etc.
The vapor and other gas ,which is evaporated from vacuum separator, first drop in temperature and are rid of moisture in condenser, then are condensed again in cooler which has retarded exchange media .the reductive condensed water are discharged by water receiver,the dry gas ,which are condensed and rid of moisture twice,are discharged to air by vacuum pump so that it protects vacuum pump.
The plant is characterized by small size,light weight,rich color, and our company can produce trail car type and closed type (alloy shield) according to the customer's requirement.
In order to make sure that the stable of oil purifier plant which can work long time and extend the life of the machine, the oil purifier's main parts such as electric control parts, electric motor, vacuum pump,oil pump are imported from SIEMENS,LEYBOLD,ABB etc.
People love “do’s and don’ts” lists. A quick Google search will yield 10.9 million hits for what to do and not do. A quick scan through the endless supply of D&D lists will show that many of the subjects people feel the need on which to provide unsolicited consulting really don’t have a defined method of approach beyond common sense. For example, the do’s and don’ts of air travel barely stretch outside the realm of common sense. Advice such as “Do not place your firearm in your carry-on luggage” or “Do not smoke while in the aircraft” goes without saying. Then there are the do and do-not-do lists for topics that are highly subjective such as fashion (Don’t wear white after Labor Day).
Thankfully, in the realm of oil analysis and machinery lubrication, few do’s and don’ts can be considered subjective. In this case, we’re talking about what to do and not do related to oil sampling for analysis. These simple rules will make or break the integrity of your sample, which is meant to drive your maintenance and reliability decisions.
Oil analysis is a condition monitoring tool designed to monitor:
- fluid properties, or the condition of the oil and the additives;
- fluid contamination; and,
- machine wear.
However, the analysis of a sample greatly depends on the quality of the sample itself. A high-quality sample translates into one that is rich with data and free from noise. The content of this article is nothing new. Dozens (if not hundreds) of articles, papers and books have had some advice for us to follow when extracting a sample of oil from a machine for analysis. However, as an industry, we don’t seem to get it right.
The same rules for oil sampling still apply, just like they always did. Here is the most recent do and do-not-do list for oil sampling from my perspective.
1) DO sample from running machines. DO NOT sample “cold” systems.
This rule goes beyond simply starting the machine to take the sample. The ideology behind oil analysis is to capture a “snapshot” of the system at the time of sampling. The timing of the sampling should be when the system is under the greatest amount of stress. Typically, the best time to sample a system is when the system is under normal working load and normal conditions. This can be a tricky task when sampling from a system that continuously cycles during normal production, such as the hydraulic system on an injection molding machine. It’s under these conditions that we’ll capture a sample that best represents the machine conditions most likely to cause accelerated wear.
2) DO sample upstream of filters and downstream of machine components.
Filters are designed to pull out wear debris and contaminants, so sampling downstream of these data-strippers provides no value. However, taking a sample before and after a filter for a simple particle count will allow you to see how well the filter is currently operating. Obviously, we expect the particle count before the filter to be higher than after the filter. If it’s not, it’s time to change the filter. Condition-based filter changes can be very important for sensitive systems and expensive filters.
3) DO create specific written procedures for each system sampled. DO NOT change sampling methods or locations.
Everything we do in oil analysis and machinery lubrication should have a detailed procedure to back up the task. Each maintenance point in the plant should have specific and unique procedures detailing who, what, where, when and how. Oil sampling procedures are no different. We need to identify the sample location, the amount of flush volume, the frequency of sampling, the timing within a cycle to sample, and indicate what tools and accessories to use on that specific sample point based on lubricant type, pressure and amount of fluid required.
4) DO ensure that sampling valves and sampling devices are thoroughly flushed prior to taking the sample. DO NOT use dirty sampling equipment or reuse sample tubing.
Cross-contamination has always been a problem in oil sampling. The truth of the matter is that flushing is an important task that is often overlooked. Failure to flush the sample location properly will produce a sample with a high degree of noise. Flushing prior to sampling needs to account for the amount of dead space between the sample valve and the active system multiplied by a factor of 10. If there is a run of pipe 12 inches long between the sample valve and the active system that holds one fluid ounce of oil, you need to flush a minimum of 10 fluid ounces before taking the sample for analysis. Flushing the dead space also will flush your other accessories such as your sample valve adapter and new tubing.
5) DO ensure that samples are taken at proper frequencies. DO NOT sample “as time permits.”
Many of those responsible for taking oil samples rarely see the results of the analysis. One of the most powerful aspects of oil analysis is identifying a change in the baseline of a sample and understanding the rate at which the change has occurred. For example, a sample of new oil should have zero parts per million (ppm) of iron when tested as the baseline. As regular sampling and analysis continues, we may see the iron level increase. An increase of 10 or 12 ppm per sample may be considered critical; however, if the frequency is not consistent, what is considered normal becomes very subjective. If our frequency of sampling is 12 months, a rise in iron of 12 ppm isn’t a major cause of concern. If our frequency is weekly, a rise in iron of 12 ppm is very concerning. Setting up the appropriate sampling frequency and adhering to it will allow for precise analysis and sound maintenance decisions.
6) DO forward samples immediately to the oil analysis lab after sampling. DO NOT wait more than 24 hours to send samples out.
As mentioned earlier, oil sampling is much like taking a snapshot of your system at a point in time. The health of a lubricated system can change dramatically in a very short period of time. If a problem is detected in a system, the earlier it is detected, the less catastrophic potential it may have. Jumping on a problem early will not only allow you time to plan for a repair, but the repair will potentially be less significant.