Dry Hydraulics Water Absorber? The 192 Top Answers

Hydraulic Oil Explained – A Simple Guide If you’ve ever felt the pressure to choose the right hydraulic oil for your machines, you know all too well the minefield of information that can be found in books or on the internet. Instead of getting lost in the world of hydraulic fluids, hydraulic fluids or hydraulic lubricants, take a look at our easy-to-follow guide to hydraulic oils. Everything you need to know about hydraulic oils! Alternatively call us on 0330 123 1444 to place an hydraulic oil order with us. Available for delivery nationwide within 48 hours of purchase, we’ll have your business up and running in no time.

What is hydraulic oil? Hydraulic oil is an incompressible fluid used to transmit power in hydraulic machinery and equipment. Also known as hydraulic fluid, hydraulic oil can be synthetic or mineral based. As a hydraulic oil supplier, Crown Oil trades 99% in mineral oil-based hydraulic oils. Although this useful fluid is commonly used in power transmission, hydraulic fluid can act as a sealant, coolant, and lubricant in machinery and equipment. The main difference between synthetic and mineral hydraulic oil The majority of the oils produced are either mineral or synthetic. Mineral-based hydraulic oils are derived from crude oil fractions, while synthetic hydraulic oils are made from chemically manufactured base fluids. Synthetic oils can be formulated to impart superior physical properties compared to mineral oils, such as high temperature performance, biodegradability, and oxidative stability.

How do hydraulic systems work? The key role of hydraulic oil in a hydraulic system is to transmit power from one end of that system to the other through the various hydraulic components. When an external force is applied to the incompressible hydraulic fluid – usually from a piston in a cylinder – the oil is forced through the hydraulic system, eventually creating a force on another part of the system. This leads to a movement or action. Normally, the application of force to material results in compression, so you may be wondering whether or not hydraulic oil is compressible, but a key property of hydraulic fluids is that they need not be compressible. “Incompressible” means that the liquid cannot be compressed. Liquids are compressible to some degree, but it’s incredibly negligible and won’t be considered for our guide. Gases, on the other hand, are compressible and are therefore not used in hydraulics.

What is hydraulic oil used for? Hydraulic fluids are used in many applications across all industries. To give you an idea of ​​the many uses of hydraulic fluid and why industrial hydraulic fluid is so important, here are 10 examples of equipment and machines that use hydraulic fluid: Forklifts – The hydraulic system in forklifts and stackers is important to help, the incredible to power powerful forks that need to lift some super heavy goods. Log Splitter – The ram mechanism of a hydraulic oil log splitter requires hydraulic fluid inside to give it the immense power that can split wood with ease. Log splitters are also known as log splitters! Car Jacks – Car lifts (jacks, car jacks, etc.) require hydraulic jack oil to support their impressive power range! This type of machine relies heavily on reliable hydraulic oil for both safety and performance. Hydraulic fluid for a lift tends to have a higher viscosity grade for high pressure. Wright Standers – A Wright Stander is a stand-on lawnmower that is typically good for cemeteries and other restricted lawns. The hydraulic part of these machines requires hydraulic oil for power supply. Snow Plows (Snow Plows) – Hydraulic oil for snow plows and plow equipment is essential for the powerful operation of the hydraulic lifting, tilting and angling movements of the snow plow blade. The cold weather conditions associated with using a plow mean that the hydraulic fluid used in a snow plow is mixed with anti-freeze additives. Skid Steer Loader (Skid Steer Loader and Skid Steer Loader) – Skid steer loader hydraulic oil is as versatile as the machine it works with. Hydraulic oil plays a major role at all times in the many tasks that this machine can handle with ease. Aircraft (Aviation) – In the aviation sector, it is imperative that aircraft hydraulic oil is reliable as it is used for flight control systems, aircraft hangar doors, aircraft jacks and aircraft controls. Air Tools – Air tools and air compressors require high-pressure hydraulic oil that contains anti-wear additives for protection. Tractors – Tractor hydraulic oil is required to operate hydraulic brakes and hydraulic systems on agricultural vehicles and machinery. For your tractor hydraulic oil supply, you should go with a reputable manufacturer to ensure your expensive machinery and vehicles are well looked after and protected. Cruise Ships and the Shipping Industry – If you’ve been lucky enough to ride aboard a cruise ship, you’ll have felt the comfort of being at sea. Hydraulic oil is used for the stabilizers on board many seagoing vessels. The stabilizers reduce roll, which can affect the ship’s balance and cause unfriendly seasickness. This is just one of many other applications on ships that require hydraulic oil.

Hydraulic Fluid Properties The properties and characteristics of any hydraulic fluid are critical to your hydraulic system’s ability to perform under the operating conditions in which you must use it. This is especially true for industrial or commercial hydraulic oils. For a hydraulic oil to be useful, it must have the following properties: Incompressible

Thermally stable over a range of operating temperatures

fire resistance

Non-corrosive to his system

Wear-resistant for his system

Low tendency to cavitation

Water compatibility (resistance to water pollution)

Total water repellency

Constant viscosity, independent of temperature

Long life

Inexpensive Few, if any, liquids meet the above criteria perfectly. However, there is a comprehensive range of hydraulic oils that specialize in meeting the above properties for the conditions in which they must operate. These conditions can range from low temperature operation (winter hydraulic oil), high temperature operation, and a variety of others.

The ingredients of hydraulic oil Hydraulic oil is made from a variety of different ingredients with a base fluid. These ingredients can often be mixed depending on the type of oil you want. Hydraulic fluids generally consist of: Mineral oil

ester

glycol

silicone

ether

ester

Some other chemicals that are hard to pronounce! For the diverse applications of hydraulic fluid, mixers mix the base oil with additives of different types to give the oil different properties.

Hydraulic Oil Additives Depending on how you use our hydraulic oil, there are additional additives that help it perform under different conditions. Various additives for hydraulic fluids include: Anti-wear – helps extend the life of equipment and machinery, you will see this in Type AW hydraulic fluids.

Cold Flow – additives that enable use in extremely cold weather conditions

Defoamer – A hydraulic oil defoamer reduces foaming in the fluid that can be caused by cleaning agents. This foaming can reduce the lubricity of the product and cause damage.

Antioxidant – Allows longer run times without oil changes while reducing sludge build-up.

Rust Prevention – Forms a protective layer that reduces the risk of rust damage from exposure to oxygen. These additives are used individually and together in various mixtures created for different purposes. The properties of hydraulic oils can be altered depending on the additives used, but the typical properties are usually high viscosity index and incompressibility. Below is a list of common uses for hydraulic oil and the types of additives that can be added to the oil to help it perform at its best. Winter Hydraulic Oil Hydraulic power is needed in some of the coldest places on earth. In these cases, antifreeze additives are used to prevent the liquid from freezing or growing. Low temperature hydraulic oil is commonly used to refer to fluids that must be used in freezing conditions. Hydraulic Oil for High Temperature Applications In high heat, oil becomes less viscous and flows more easily, which means it can leak or lose its required properties. Additives are used to maintain the viscosity of fluids used in applications that are exposed to higher temperatures. Hydraulic Oil for Heavy-Duty Use Heavy-duty hydraulic oil is required for high-pressure environments where the fluid must withstand heavy loads. The hydraulic oil additives used here typically contain anti-wear properties. Anti-wear hydraulic oil is one of the most commonly used blends in industry and construction. Environmentally Friendly Hydraulic Oil Biodegradable hydraulic oil is used in applications where an oil spill or leak could potentially contaminate the environment. The typical base oil for biodegradable versions of hydraulic oils is canola oil and some other vegetable oils. Environmentally friendly hydraulic oil is a strong consideration for those who use hydraulic machinery on farms, forests or similar environmentally sensitive locations. This is because the oil is made from a biodegradable base liquid and will therefore naturally degrade in the event of a spill.

Water and oil don’t mix – that’s a well-known saying in the lubricants industry. But what exactly does that mean? Yes, water pollution can be a problem, but how can water be measured? Can it be controlled? What are the best ways to remove it? This article provides an overview of the adverse effects that water contamination can have on hydraulic and other lubrication systems and discusses ways to measure, control, and remove water.

Figure 1. Saturation curve for a typical turbine lubricating oil

states of water

Water can exist in hydraulic fluids and other lubricants either as dissolved, emulsified, or free water. The point at which the liquid cannot hold any more dissolved water is called the saturation point. If there is more dissolved water than the liquid can hold, the excess water (or free water) can exist either as a separate water phase or as an emulsion.

Typically, supersaturated liquids appear cloudy. How much water a fluid can hold at saturation is highly dependent on the type of fluid base stock, additive package, temperature and pressure. For example, highly refined mineral oils with few additives hold little water before becoming saturated, around 100 parts per million (ppm) at 70°F.

On the other hand, ester-based hydraulic fluids used in rolling mill applications can have saturation levels in excess of 3,000 ppm at 70°F and even higher at higher temperatures.

A saturation curve for a typical turbine lubricating oil (Figure 1) illustrates the relationship between temperature and degree of saturation: if a system is operating at 100°F and the fluid contains only dissolved water (100 ppm), then a drop to ambient temperature (≈70°F), such as during a shutdown, would result in the presence of free water in the system since the saturation level is less than 100 ppm at ambient conditions.

On the other hand, warm water intrusion can also lead to the presence of free water if the saturation level is reached or exceeded (at 100°F this would be 200 ppm).

Figure 2. Bearing relative fatigue life1

water sources

Water can come from different sources. Examples of environmental leakage include rain leakage into external reservoirs, seepage through reservoir covers, access hatches, vents or deteriorated seals, and condensation from the air in reservoirs and other system areas. Water can also enter the fluid system from the process side, from leaking heat exchangers or chillers, or through direct ingress of process water such as cooling water, rinse water, or steam.

Water intrusion can be minimized with clever system design and good housekeeping, but eliminating all water sources entirely is difficult (and costly).

The Effect of Water

The presence of water in hydraulic fluids and lubricants can have far-reaching effects on system components. Surface corrosion, probably the most obvious effect, is directly related to the presence of free water. Accelerated metal surface fatigue, such as B. in camps, can be promoted even if all the water present in the liquid is dissolved. This was investigated in 1977 by Cantley1 who studied the effect of dissolved water on the fatigue life of tapered roller bearings.

Cantley developed an equation that relates relative bearing life and the water content of the lubricant used in the tests, an SAE 20 fluid with rust and antioxidant additives. He showed that bearing life could be extended by a factor of five if the bearing lubricant contained as little as 25 ppm dissolved water compared to 400 ppm, which is near the saturation level at the 150°F test temperature. Figure 2 shows an adaptation of the Cantley results and illustrates the strong correlation between water content and relative bearing life.

Figure 3. Capacitive water sensing technology

Other effects of water on fluid systems are reduced lubricating properties (film thickness, load carrying capacity, etc.) caused by the presence of water, which can lead to increased component wear2, and component seizing due to ice crystal formation at low temperatures.

Water not only affects the components of a hydraulic or lubrication system, it can also physically and chemically alter the fluid itself. The physical properties most affected by the presence of water include:

viscosity

Lubricity and load carrying properties

Power transmission properties (compressibility), especially in hydraulic systems

The chemical properties that even small amounts of water can have a measurable impact on are:

Thermo-oxidative stability. The reaction of oxygen with liquid basestock forms oxygenated compounds and is accelerated by heat and the presence of water. Metals in the form of abrasion often act as a catalyst. 3 Oxidation ultimately leads to higher viscosity and deposits, e.g. B. polymeric compounds or slurries.

Oxidation ultimately leads to higher viscosity and deposits such as polymeric compounds or sludge. Hydrolysis, the breakdown of ester-based fluids by heat and water, results in acids and alcohols, resulting in increased corrosivity.

Deposit behavior (soot, coking)

Premature additive depletion and additive precipitation affecting fluid performance

Table 1. Comparison of vacuum dewatering process

Measurement of water content in liquids

There are two methods commonly used to express water content in hydraulic and lubricating fluids: Absolute ppm, which expresses water content in parts per million (ppm) either by weight or by volume. This method is typically used for water content data. Relative content, expressed as a percentage of saturation, gives the content of liquid water relative to its degree of saturation at a given temperature. There is a clearer warning of the impending formation of free water.

There are a variety of techniques to measure the amount of water in hydraulic fluids and lubricants. The final choice depends on whether a quick assessment or a precise measurement is required. Some of the techniques typically employed include the following:

Of these, only Karl Fischer titration and the use of capacitive water sensors to monitor water content are useful as these are more accurate quantitative methods.

The classic method of monitoring water content is to take a representative sample and send it to a laboratory for analysis, usually Karl Fischer titration. Although this is a reliable and accurate method, the main disadvantage is the time lag between sampling and analysis results.

Capacitive water sensor

A capacitive water sensor, on the other hand, offers real-time monitoring and can be used as a control device. This device is a further development of the humidity sensor. It consists of a capacitive cell formed by inserting a dielectric polymer between electrodes (Figure 3). The lower electrode is deposited on a moisture-impermeable ceramic substrate, while the upper capacitor plate – a dielectric polymer – allows the transfer of water molecules.

Water molecules migrate in or out of this layer depending on the moisture of the polymer relative to the fluid. This changes its dielectric constant and thus the capacitance of the capacitor. This change in capacitance is then converted to a signal proportional to the degree of saturation of the liquid over a percentage range of zero to 100, where 100 percent saturation corresponds to the solubility limit of water in the liquid at the given temperature.

The water saturation values ​​can be related to the absolute water concentration (ppm) via an algorithm using liquid parameters determined for the specific brand of liquid in conjunction with the liquid temperature via a calibration curve.

Karl Fischer titration

The reference for this conversion is the Karl Fischer method for determining the absolute water content in liquids.4 This conversion requires the liquid temperature to be measured at the water sensor, which is achieved using an integrated resistance temperature detector (RTD). Sensor. Note that the white dots in Figure 3 represent the porosity of the gold layer.

Figure 4. Choosing the right level of control

Adjusting the water control levels

For most industrial hydraulic and lubrication systems, a properly set control level, typically recommended at 50 percent saturation or less, will minimize the deleterious effects of water contamination. If possible, the control stage should be selected at the lowest system temperature to be expected, e.g. B. in a cold environment during a shutdown.

As shown above, most liquids can hold less water at lower temperatures. To prevent free water formation at any given system condition, the control level should be set at least to the saturation level at the lowest expected temperature. However, this does not account for water intrusion, so it is recommended to set the control level at 50 percent saturation as this will protect against surface corrosion or loss of fluid properties (e.g. lubricity, compressibility) due to the presence of free water.

In addition, this also keeps the absolute water content reasonably low, slowing down any chemical reactions that depend on water as one of the reactants (e.g., liquid hydrolysis and component surface degradation). Figure 4 illustrates this methodology.

Figure 5. Spray Nozzle Mass Transfer Cleaner

Water Removal Methods

An integral part of effective water control is the ability to efficiently remove water from the hydraulic or lubrication system. Some of the water removal methods are discussed below.

Drain: Most hydraulic and lubrication systems have reservoirs sized to promote the removal of contaminants; Air rising to the free surface and water falling to the ground. Draining the tank regularly is an inexpensive way to remove free water and automatic drain valves are available to reduce maintenance time.

Centrifuges separate water from liquids by centrifugal force, using differences in specific gravity between the liquid and the water for the separation. They remove free and some of the emulsified water (depending on the relative stability of the emulsion), but do not remove dissolved water. Centrifugal separation is suitable for continuous decontamination of liquids, but requires excellent water demulsibility (oil/water separation). High investment and maintenance costs as well as high energy requirements are some of the disadvantages of this technology.

Coalescers separate water droplets from the liquid stream by stopping them on or near the surface of a filter or screen, causing the droplets to fuse (coalesce) together and grow to a size that allows them to fall to the bottom of the vessel where they can be extracted. Coalescers cannot separate dissolved water. Because coalescers rely on the interfacial tension between the water and the liquid phase, they tend to become ineffective in the presence of surfactants in the liquid. They also require fine upstream filtration to remove any particulate contamination that could clog the coalescer and render it ineffective.

Absorbent filters remove free and emulsified water through super absorbent polymers impregnated into the filter matrix. Absorptive water removal is not well suited when large amounts of water are present in the liquid and no dissolved water or highly emulsified water is removed.

Vacuum dewatering cleaners are used to dry hydraulic fluids and lubricants by subjecting them to a partial vacuum. Two technologies are available, flash distillation, vacuum dehydration and mass transfer vacuum dehydration. While both processes use the concentration gradient between the liquid and the evacuated air to evaporate the water from the liquid, flash distillation technology also applies heat to boil off more water and operates at a higher vacuum. This makes flash distillation more efficient as it removes more water from the liquid than a mass transfer device. Table 1 highlights the main differences between the two technologies.

The high temperature and high vacuum used in flash stills can result in the loss of lower boiling basestock fractions and volatile additives, and can lead to thermo-oxidative degradation of the liquid – serious disadvantages when liquid integrity must be preserved.

Mass transfer cleaners are recommended due to their minimal effect on the chemical and physical properties of fluids. A typical unit is shown in Figure 5. The liquid is directed into the vacuum chamber where it is spread into a thin film to reduce the path length for the water to reach the free surface and so be transferred to the air. This can be done in a number of ways.

In Figure 5, an aerosol mist is created by pumping the liquid through spray nozzles. Alternative technologies commonly used divert the fluid via stacked rings or onto a rotating disc. The vacuum in the vessel is about 20 percent atmospheric pressure and the air expands to about five times its original volume.

Therefore, when the air is at 100 percent relative humidity (100 percent saturation), the evacuated air flowing through the liquid mist is at 20 percent relative humidity and absorbs the water vapor from the liquid until the liquid and air contain water in equilibrium. Depending on the vacuum, mass transfer cleaners can remove all of the free water and up to 80 percent of the dissolved water from the liquid.

In combination with a water sensor, mass transfer purifiers can be used to continuously control the water in hydraulic and lubrication systems; but not to the low percent saturation levels achieved with cleaners. (Vacuum) pressure is the main factor.

Conclusions

Water is a significant contaminant in hydraulic and lubricating fluid systems, leading to system component and fluid deterioration.

Significant cost savings can be achieved by operating with dry liquids. Recommended saturation level: 50 percent or less for typical petroleum based fluids.

Water monitoring techniques must be accurate, repeatable and real-time so that an increase in water content can be promptly corrected. Online monitoring of water via a capacitive water sensor offers an optimal and cost-effective solution for monitoring.

Because of the minimal effect on fluid properties, mass transfer vacuum dewatering cleaners are recommended for water removal from hydraulic fluids and lubricants.

Read more about water-in-oil contamination:

How to measure water in oil

Options for removing water from oil

Removal of water contamination from oil

Best ways to test for water in oil

references

CONCERNING. Cantley. “The Effect of Water in Lubricating Oil on Bearing Fatigue Life.” ASLE Transactions, American Society of Lubrication Engineers, Vol. 20, No. 3, p. 244-248, 1977; from a presentation at the 31st ASLE Annual Meeting, Philadelphia, Penn. J Fitch and S Jaggernauth. “Moisture, the Second Most Destructive Lubricant Contaminant and Its Impact on Bearing Life.” P/PM technology, p. 50-53, 1994. M. Weinschelbaum. “A study of the invisible but measurable particulate contamination in hydraulic systems.” Proceedings of the National Conference on Fluid Power, Volume XXIII, p. 265-277, 1969. K. . Farooq and R. Fowler. “Comparison of water measurement results in polyol ester based lubricating fluids by the coulometric Karl Fischer method and a thin film polymer capacitive water sensor.” JOAP International Condition Monitoring Conference, 3.-6. April 2000.

About the author

About the author

By Josh Cosford, Contributing Editor

Most hydraulic fluids are oil based, so let’s not forget the adage that oil and water don’t mix well. However, when it comes to the energy transfer of the hydraulic oil in your hydraulic system, there is much more at stake. Whether free or saturated, the potential damage from water is more damaging than just pooling at the bottom of your reservoir.

Almost every beneficial property of hydraulic oil is reduced or impaired when it is contaminated with water. Water contaminates hydraulic oil in two ways; either as free water or as saturated water. Free water is what exists as pockets or bubbles of individual water droplets. Saturated water is the dissolved kind – it shares the space within the oil itself. Hydraulic oil, like air, can be moist and it is almost impossible to remove all of the moisture from the oil, but you want to keep it to a minimum.

At water relative humidity levels below 99%, the water remains fully dissolved, but temperature differences cause free water to “rain” out of the liquid. Even if you could keep the water saturation just under 100%, the excess water gives the oil a telltale milky appearance. Milk oil is terrible under any circumstances.

Oil contaminated with water reduces the lubricity of the hydraulic oil. The viscosity and shear strength of the oil creates a film barrier between two wear surfaces. Water contamination reduces both viscosity and shear strength, allowing metal-to-metal contact to occur. Although water-saturated oil can still provide full film lubrication under pressure, it loses this protection in low-pressure areas.

A lesser-known fact about “wet” oil is its accelerated rate of oxidation. Oil oxidation rate increases with heat, which is common in many hydraulic systems. The increased oxidation causes oil molecules to break up, which in turn creates varnish when the separated atoms stick together and contain additives in the oil. (The oxidation discussed here affects the oil itself, not the metal components exposed to it.)

It’s easy to associate oxidation with the rusting of metal components that also occurs in water-contaminated hydraulic systems. Water-based hydraulic fluids use rust-inhibiting additives, but since hydraulic oil is inherently rust-inhibiting, highly saturated oil offers little such protection. The case is exacerbated when free pools of water form in steel or ironwork, particularly during downtime. Of course; You must avoid excessive water pollution at all costs.

If your home heating system runs on oil, rely on your oil tank to safely store and protect that oil. Unfortunately, oil tanks are not impenetrable, so there are times when water can seep into your tank.

How to tell if you have water in your tank

It is not always easy to determine if there is water in your oil tank. Since oil rises from the water, looking into the top of your tank doesn’t tell you much. It’s especially difficult if you have an underground tank. If water in your tank goes undetected for a long time, you may notice when you have problems with your heating system. To avoid these problems, take preventive measures by properly maintaining your tank and checking it regularly for water.

If you are concerned you may have a water problem, or are just doing a routine check, the easiest way to test the inside of your tank is with a water test paste. This method is easy and reliable – just make sure to check the manufacturer’s directions for the specific water-seeking paste you’re using. Generally, however, you simply coat the underside of a probing rod or string with the paste and lower it to the bottom of your tank. It is important that you make sure it reaches the bottom as that is where water will settle if it is present. When the paste detects water, it takes on a color, e.g. B. yellow or red. The color can also indicate the amount of water detected. If you find a large amount of water, you should contact a professional technician immediately.

How and why water gets into your oil tank

Oil tanks are designed to keep water out, so you may be wondering how this problem arises in the first place. The reality is that water is a natural part of our atmosphere and oil tanks are not completely waterproof. The water found in oil tanks likely comes from one of two sources – rainwater or condensation. Understanding which of these is the cause of your tank’s water problem will be helpful for future prevention.

Rainwater: Outdoor tanks are more exposed to the elements and can therefore be more vulnerable to water. If a lid or tank cap is not completely closed, rainwater can easily enter the tank. Most above-ground tanks are placed close to home, where gutters can also be a problem. Overflow from gutters can get into any opening in your tank. Even if you make sure your tank is properly capped, you could still have a problem due to the condition of the tank itself. For example, age or lack of maintenance can cause your tank’s seals to deteriorate, its vents to become damaged, or your tank’s body to rust or crack. Any of these problems can cause water to enter the tank.

Condensation: Indoor and outdoor tanks are equally prone to condensation. Condensation can occur whenever a partially filled vessel is prone to condensation. Condensation can occur whenever the vents of a partially filled tank let in moist air. When the internal temperature of the tank is cooler than the ambient outside temperature, the humid air inside the tank cools, causing the water vapor in the air to become water droplets. These water droplets then stick to the inner walls of the tank and eventually settle to the bottom of the tank. A few drops of water are not a big problem, but condensation can accumulate significantly over time.

Also note that with an underground oil tank, groundwater can seep in through perforations. If water gets in this way, it can also mean that oil is leaking out, which is a serious problem. If your underground tank is damaged in any way, you should seek professional help to repair or replace it

How to remove the water from your oil tank

If a test shows that you do indeed have water in your tank, you should address the issue immediately. The most effective way to get water out of your tank depends on the type of tank and the amount of water inside. In general, if there is more than a few inches of water at the bottom of your tank, you should rely on professional help to remove water. For small amounts of water, however, you can often use it yourself. You will also need to seek professional help if due to a problem with your tank, e.g. B. a broken seal or perforation, water could penetrate. This is especially important because openings that let water in can also let oil out. Let’s look at a few ways you can remove water from your heating oil tank:

Drain: If you have a metal oil tank, look for a mud valve at the bottom of the tank. You can drain water by opening this valve. You may not get every break out this way, but at least it’s a good start. Runoff water also contains some oil, so you need to be careful about how you collect and dispose of it. Don’t let it spill on the floor and definitely don’t throw it down the drain. Your local authority should be able to direct you to the correct disposal site, where the contaminated water is likely to be diverted to a tank intended for waste oil.

Don’t let it spill on the floor and definitely don’t throw it down the drain. Your local authority should be able to direct you to the correct disposal site, where the contaminated water is likely to be diverted to a tank intended for waste oil. Pump It: If you have a plastic tank that doesn’t come with a mud valve, you can siphon the water out with a hand pump. You may be able to handle small amounts on your own, but you should rely on a professional to pump large amounts. Again, this method may not get all of the water out, but it should greatly reduce it.

Absorb: For smaller amounts of water, you can use substances that naturally absorb water to extract it from your oil tank. There are a few different ways you can do this.

Alcohol Based Dispersants: One way to absorb water is by using a water dispersant additive. These oil tank additives are typically alcohol based and inherently absorb water. To use it, simply pour the additive into your tank and let it work. Some additives are designed not only to absorb water, but also to break up sludge. If you use any of these additives, be aware that they can clog your oil filter. This can happen if the broken-up deposits get into your oil lines. Water Absorbing Sock: Another way to soak up water is to put an absorbent material in your tank for a prescribed time and then remove it. These devices vary somewhat in shape and size, but they are typically made of cloth and chemically treated to be extra absorbent. Some water-absorbent socks can soak up about two cups of water. If you have more water but not so much that you should pump it out instead, you may need to buy more than one sock or find one that’s reusable. You can tell when you’ve fully saturated one, which lets you know you’ll either have to reuse it or insert another one to complete the job.

Whichever method you use, you may not be done after just getting the water out of your tank. After the water is removed, the boiler feed line may need to be flushed and the fuel filters replaced. In most cases, you should contact a professional to get this job done.

Possible damage if the water is not removed from the tank

Water may seem harmless, but it can wreak havoc on your heating system. Let’s look at some problems that water can cause in your oil furnace or tank:

Rust: If water is left in your tank long enough, internal corrosion can occur. Most steel oil tanks are more likely to rust from the inside out than from the outside in. This rust can lead to further complications such as leaks and an overall drop in the efficiency of your system. Your furnace or fuel pump can also be damaged if your tank is rusty on the inside. Rust, water and oil at the bottom of the tank form a sludge that can contaminate your stove’s fuel supply.

ply to your oven. Freezing: Because oil has a low freezing point, cold temperatures are not a problem for oil unless they are extreme. However, water freezes at only 32 degrees Fahrenheit. So if you have water in an outdoor tank and it’s exposed to cold temperatures, it can freeze. Freezing can cause blockages in the oil supply line and stop oil flow. This can lead to total heat loss, which is a real crisis in winter when trying to keep your home warm.

Because oil has a low freezing point, cold temperatures are not a problem for oil unless they are extreme. However, water freezes at only 32 degrees Fahrenheit. So if you have water in an outdoor tank and it’s exposed to cold temperatures, it can freeze. Freezing can cause blockages in the oil supply line and stop oil flow. This can lead to total heat loss, which is a real crisis in winter when trying to keep your home warm. Bacteria: Water in your tank creates a breeding ground for bacteria. The bacterial growth turns into a sludge that settles at the bottom of the tank. The real problem with these bacteria is that they release acid that can cause corrosion in your tank, fuel lines, burners, and filters. This corrosion can cause leaks and other serious problems that can bring your system to a standstill.

This will prevent water from getting into your oil tank

Once you’ve taken care of your current water problem, you should take steps to prevent the same problem from happening again. Let’s discuss nine steps you can take to keep your heating oil system running while protecting against the damaging effects of water in your tank.

Close the lids of your tank: This may seem obvious, but it is important that you ensure that the lid or filler cap of outdoor tanks is not open or even loose. Keep these openings to your tank properly sealed to prevent rainwater from entering. Give your tank a one-time check: Make it a habit to visually inspect your tank yourself on a regular basis. At the very least, look for signs of oil leaking from the tank. Also look for signs of aging like light rust or paint chipping, as well as more serious problems like heavy rust, calcification or perforations. Perforations are an immediate problem, and heavy rust and scale indicate the metal is thinning. If you have an underground tank, keep an eye on its surroundings. Wilting plants indicate that there could be an oil leak due to a perforation in your tank. Make it a habit to visually inspect your tank yourself on a regular basis. At the very least, look for signs of oil leaking from the tank. Also look for signs of aging like light rust or paint chipping, as well as more serious problems like heavy rust, calcification or perforations. Perforations are an immediate problem, and heavy rust and scale indicate the metal is thinning. If you have an underground tank, keep an eye on its surroundings. Wilting plants indicate this is due to a perforation in your tank. Have your tank checked: In addition to your more frequent self-checks, you should have your tank checked thoroughly. This check should be done before the cold weather sets in to ensure your heating system is in good condition and ready to keep your home warm during the cold season. In addition to your more frequent self-checks, you should have your tank thoroughly inspected by an experienced technician at least once a year. This check should be done before the cold weather sets in to ensure your heating system is in good condition and ready to keep your home warm during the cold season. Test Your Tank: Since catching water in your tank early can save your tank from numerous complications and excessive costs of repairing or replacing your damaged tank, it is wise to check for water regularly. Using a water detection paste to perform routine checks will give you peace of mind when you see your tank is out of water, or alert you to the problem if water is ever present. Outdoor buried tanks also allow you to test for soil contamination. Oil in the ground around your tank indicates a leak that is an environmental hazard and may allow groundwater to enter your tank and contaminate the oil within. This is not an uncommon problem – according to the EPA, over half of regulated underground tanks are leaking. Absorb water from your tank: Another way to be sure you’re on top of water issues is to always have a water-absorbent sock in your tank. Check the manufacturer’s instructions to see how long you can leave it, but it can probably sit for a few months before it needs changing. When you take them off, you can tell from the sock whether it has absorbed water, so it can also serve as an endurance test. Be sure to dispose of these socks carefully as they are contaminated with oil. Keeping water absorbent socks in your oil tank ensures that water cannot settle to the bottom of your tank, which protects your tank from water-related damage. Change the temperature of your tank: Because condensation is caused by temperature differences between the inside of a tank and the outside air, there are a few things you can do to reduce this problem. In general, outdoor tanks will have less condensation if placed in the shade rather than in the sun. This is relevant information to consider when choosing a spot for your outdoor storage tank. If the location of your tank is already determined, you may wish to paint your tank with reflective aluminum paint so that it reflects the sun’s rays. You can also build a structure around your tank to provide shade in the summer and serve as a heated enclosure in the winter. Keeping your tank heated during the winter will keep your oil from gelling and water in it from freezing. Replace Your Tank: If your tank is showing signs of wear, either from the corrosive effects of water or simply from age and use, it may be time to replace it. Typically oil tanks, possibly more common depending on the harsh environment. When moving into a new apartment with oil heating, you should inquire about the age of the oil tank. Even if your aquarium is relatively young, you should replace your aquarium if you have an ongoing water problem that is otherwise unavoidable. If your tank is showing signs of wear, either from the corrosive effects of water or simply from age and use, it may be time to replace it. Oil tanks typically need to be replaced every 15 to 20 years, possibly more frequently depending on the harsh environment. When moving into a new apartment with oil heating, you should inquire about the age of the oil tank. Even if your aquarium is relatively young, you should replace your aquarium if you have an ongoing water problem that is otherwise unavoidable. Clean your tank: Having your tank cleaned professionally on a regular basis will help remove water and bacterial sludge from your tank. This is not a job you can do alone as you will have to pump out the entire tank. Instead, contact your oil supplier to give your tank a thorough cleaning. You’ll also likely pour alcohol-based additives into your tank to further protect it. Experts recommend having the tank cleaned at least every five years. Having your tank professionally cleaned regularly can remove water and bacteria-laden sludge from your tank. This is not a job you can do alone as you will have to pump out the entire tank. Instead, contact your oil supplier to give your tank a thorough cleaning. You’ll also likely pour alcohol-based additives into your tank to further protect it. Experts recommend getting your tank cleaned Keep your tank full: Leaving your outdoor area can cause condensation in the tank. This applies in particular to fluctuating outside temperatures and humid air. For this reason, you should not leave your tank underfilled for long periods of time. Test your oil level and have the oil delivered to your home before it almost runs out. Leaving your heating oil tank outdoors at a low level can result in condensation inside the tank. This applies in particular to fluctuating outside temperatures and humid air. For this reason, you should not leave your tank underfilled for long periods of time. Test your oil level and have the oil delivered to your home before it almost runs out.

As you can see, there are many ways you can prevent water problems in the future. The most important thing is to be aware of what is going on in and around your tank to catch problems early. It’s important to take care of the problem before it has time to get out of hand. Remember that water can only cause serious damage when it accumulates and eventually causes corrosion, freezes, or breeds bacteria.

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It was not until the beginning of the Industrial Revolution that a British mechanic named Joseph Bramah applied the principles of Pascal’s Law to develop the first hydraulic press. In 1795 he patented his hydraulic press known as the Bramah Press. Bramah found that if a small force on a small area would produce a proportionately larger force on a larger area, the only limit to the force a machine can apply is the area over which the pressure is applied.

What is a hydraulic system?

Hydraulic systems can be found in a wide range of applications today, from small assembly processes to integrated applications in steel and paper mills. By applying Pascal’s law, which states: Hydraulics allow the operator to perform significant work (lifting heavy loads, turning a shaft, drilling precision holes, etc.) with a minimal investment in a mechanical linkage.

“Pressure exerted at any point on an enclosed liquid is transmitted unabated in all directions through the liquid and acts on every part of the enclosed container at right angles to its internal surfaces and equally on equal areas (Figure 1).”

Figure 1 – Pascal’s Law

By applying Pascal’s law and Brahma’s application, it is evident that an input force of 100 pounds per 10 square inches develops a pressure of 10 pounds per square inch throughout the confined vessel. This print supports a weight of 1000 pounds when the area of ​​the weight is 100 square inches.

The principle of Pascal’s law is realized in a hydraulic system through the hydraulic fluid used to transfer the energy from one point to another. Because hydraulic fluid is nearly incompressible, it can transmit power instantly.

Hydraulic system components

The main components that make up a hydraulic system are the reservoir, pump, valve(s) and actuator(s) (motor, cylinder, etc.).

reservoir

The purpose of the hydraulic reservoir is to hold a volume of fluid, transfer heat out of the system, allow solid contaminants to settle, and facilitate the release of air and moisture from the fluid.

pump

The hydraulic pump converts mechanical energy into hydraulic energy. This happens through the movement of liquid, which is the transmission medium. There are different types of hydraulic pumps including gear, vane and piston pumps. All these pumps have different sub-types dedicated to specific applications such as: B. a bent axis piston pump or a vane pump with variable displacement. All hydraulic pumps work on the same principle which is to displace volume of fluid against a resistive load or pressure.

valves

Hydraulic valves are used in a system to start, stop, and direct the flow of fluid. Hydraulic valves consist of disks or slides and can be operated pneumatically, hydraulically, electrically, manually or mechanically.

actuators

Hydraulic actuators are the bottom line of Pascal’s law. Here the hydraulic energy is converted back into mechanical energy. This can be done by using a hydraulic cylinder that converts hydraulic energy into linear motion and work, or by using a hydraulic motor that converts hydraulic energy into rotary motion and work. As with hydraulic pumps, hydraulic cylinders and hydraulic motors come in several different sub-types, each intended for specific design applications.

Important lubricated hydraulic components

There are several components in a hydraulic system that are considered vital due to repair costs or criticality of use, including pumps and valves. Several different pump configurations need to be considered individually from a lubrication point of view. Regardless of pump configuration, however, the lubricant selected should prevent corrosion, meet viscosity requirements, be thermally stable, and be easily identifiable (in the event of a leak).

vane pumps

There are many variations of vane pumps available between manufacturers. They all work on similar design principles. A slotted rotor is coupled to the drive shaft and rotates within a cam ring that is offset or eccentric to the drive shaft. Vanes are inserted into the rotor slots and follow the inner surface of the cam ring as the rotor spins.

The vanes and the inner surface of the cam rings are in constant contact and are subject to high wear. As the two surfaces wear, the vanes continue to come out of their slot. Vane pumps deliver a steady flow at a high cost. Vane pumps operate within a normal viscosity range of between 14 and 160 cSt at operating temperature. Vane pumps may not be suitable for critical, high-pressure hydraulic systems where contamination and fluid quality are difficult to control. The performance of the anti-wear additive in the fluid is very important in vane pumps in general.

piston pumps

Piston pumps, like all hydraulic pumps, are available in fixed and variable displacement designs. Generally the most versatile and robust type of pump, piston pumps offer a range of options for any type of system. Piston pumps can operate at pressures in excess of 6000 psi, are highly efficient and produce comparatively little noise. Many piston pump designs also tend to resist wear better than other pump types. Piston pumps operate within a normal fluid viscosity range of 10 to 160 cSt.

gear pumps

There are two common types of gear pumps, internal and external. Each type has a variety of subtypes, but all develop flow by transporting fluid between the teeth of an intermeshing gear set. Although generally less efficient than vane and piston pumps, gear pumps are often more tolerant of fluid contamination.

Internal gear pumps generate pressures of up to 3000 to 3500 psi. These types of pumps offer a wide range of viscosities up to 2200 cSt depending on the flow rate and are generally quiet. Internal gear pumps have high efficiency even with low liquid viscosity. External gear pumps are common and can handle pressures of up to 3000 to 3500 psi. These gear pumps provide cost effective medium pressure, medium volume, and fixed displacement delivery to a system. Viscosity ranges for these types of pumps are limited to less than 300 cSt.

hydraulic fluids

Today’s hydraulic fluids serve multiple purposes. The primary function of a hydraulic fluid is to provide energy transfer through the system, allowing work and movement to be performed. Hydraulic fluids are also responsible for lubrication, heat transfer, and contamination control. When choosing a lubricant, consider viscosity, seal compatibility, base material, and additive package. Three common types of hydraulic fluid found on the market today are petroleum based, water based and synthetic.

Petroleum or mineral based fluids are the most common fluids today. These fluids offer a cost effective, high quality and readily available choice. The properties of a mineral fluid depend on the additives used, the quality of the original crude oil and the refining process. Additives in a mineral fluid offer a number of specific performance characteristics. Common additives for hydraulic fluids include rust and oxidation inhibitors (R&O), corrosion inhibitors, demulsifiers, antiwear agents (AW) and extreme pressure agents (EP), VI improvers and defoamers. Additionally, some of these lubes contain brightly colored dyes that allow you to easily spot leaks. Because hydraulic leaks are so costly (and common), this ancillary property plays a huge role in extending the life of your equipment and saving your facility money and resources. Water-based fluids are used for fire protection due to their high water content. They are available as oil-in-water emulsions, water-in-oil (invert) emulsions and water-glycol blends. Water-based fluids can provide suitable lubricating properties but must be closely monitored to avoid problems. Because water-based fluids are used in applications where fire resistance is required, these systems and the atmosphere around the systems can be hot.

Elevated temperatures cause the water in the liquids to evaporate, increasing viscosity. Occasionally distilled water needs to be added to the system to correct the fluid balance. Whenever these fluids are used, several system components must be checked for compatibility, including pumps, filters, piping, fittings, and gasket materials.

Water-based fluids can be more expensive than traditional petroleum-based fluids and have other disadvantages (e.g., lower wear resistance) that must be weighed against the benefit of fire resistance. Synthetic fluids are man-made lubricants and many offer excellent lubricating properties in high pressure and high temperature systems. Some of the advantages of synthetic fluids can include fire resistance (phosphate esters), lower friction, natural detergency (organic esters and ester-fortified synthesized hydrocarbon fluids), and thermal stability.

The disadvantage of these fluids is that they are typically more expensive than traditional fluids, can be easily toxic and require special disposal, and are often not compatible with standard gasket materials.

liquid properties

When choosing a hydraulic fluid, consider the following properties: viscosity, viscosity index, oxidation stability, and wear resistance. These properties determine how your fluid performs in your system. Fluid property testing is performed in accordance with either the American Society of Testing and Materials (ASTM) or other recognized standards organizations.

Viscosity (ASTM D445-97) is a measure of a fluid’s resistance to flow and shear. A higher viscosity liquid will flow with more resistance compared to a lower viscosity liquid. Too high a viscosity can contribute to high liquid temperature and higher energy consumption. Too high or too low a viscosity can damage a system and is therefore the key factor when choosing a hydraulic fluid. The viscosity index (ASTM D2270) indicates how the viscosity of a liquid changes with a change in temperature. A high VI fluid will maintain its viscosity over a wider temperature range than a low VI fluid of the same weight. High VI fluids are used where extreme temperatures are expected. This is particularly important for hydraulic systems that operate outdoors. Oxidation stability (ASTM D2272 and others) is the fluid’s resistance to heat-induced degradation caused by a chemical reaction with oxygen. Oxidation significantly shortens the life of a fluid, leaving by-products such as sludge and varnish. Paint impairs valve function and can restrict flow paths. Wear resistance (ASTM D2266 and others) is the ability of the lubricant to reduce the rate of wear in frictional boundary contacts. This is achieved when the liquid forms a protective film on metal surfaces to prevent abrasion, abrasion and contact fatigue on component surfaces.

Aside from these basic properties, visibility is another property to consider. If there ever is a hydraulic leak, you want to catch it early so you don’t damage your equipment. Choosing a colored lubricant can help you identify leaks quickly and effectively protect your system from machine failure.

Ten steps to check the optimal viscosity range

When selecting lubricants, make sure that the lubricant will work efficiently at the operating parameters of the system pump or motor. It is useful to have a defined procedure to follow the process. Consider a simple system with a fixed displacement gear pump driving a cylinder (Figure 2).

Gather all relevant data for the pump. This includes collecting all design limitations and optimal operating characteristics from the manufacturer. What you are looking for is the optimum operating viscosity range for the specific pump. The minimum viscosity is 13 cSt, the maximum viscosity is 54 cSt and the optimal viscosity is 23 cSt. Check the actual operating temperature conditions of the pump during normal operation. This step is extremely important as it provides a reference point for comparing different fluids during operation. The pump normally operates at 92°C. Record the temperature-viscosity properties of the lubricant used. The ISO viscosity rating system (cSt at 40°C and 100°C) is recommended. The viscosity is 32 cSt at 40 °C and 5.1 cSt at 100 °C. Obtain an ASTM D341 Standard Viscosity-Temperature Chart for Liquid Petroleum Products. This table is widely used and can be found in most industrial lubricant product guides (Figure 3) or from lubricant suppliers. Using the lubricant’s viscosity properties found in Step 3, start at the temperature (x-axis) axis of the chart and scroll along until you find the 40 degree C line. Walk up the 40°C line until you find the line that corresponds to your lubricant’s viscosity at 40°C, as published by your lubricant manufacturer. When you find the appropriate line, make a small mark at the intersection of the two lines (red lines, Figure 5). Repeat step 5 for the lubricant properties at 100°C and mark the intersection (dark blue line, Figure 5). Connect the markers by drawing a line through them with a straight edge (yellow line, Figure 5). This line represents the viscosity of the lubricant at different temperatures. Using the manufacturer’s specifications for the optimal operating viscosity of the pump, determine the value on the vertical viscosity axis of the chart. Draw a horizontal line across the page until it meets the lubricant’s yellow viscosity-temperature line. Now draw a vertical line (green line, Figure 5) to the bottom of the graph from the yellow Viscosity vs. Temperature line, where it is intersected by the horizontal line of optimal viscosity. Where this line intersects, the temperature axis is the pump’s optimum operating temperature for that particular lubricant (69°C). Repeat step 8 for the maximum continuous and minimum continuous viscosity of the pump (brown lines, Figure 5). The range between the minimum and maximum temperature is the minimum and maximum allowable operating temperature of the pump for the selected lubricant product. Use the heat gun scan performed in step 2 to determine the pump’s normal operating temperature from the chart. If the value is within the minimum and maximum temperatures given in the table, the fluid is suitable for use in the system. If this is not the case, you will have to change the fluid to a higher or lower viscosity grade accordingly. As shown in the table, the pump’s normal operating conditions are outside the appropriate range (brown area, Figure 5) for our particular lubricant and must be modified.

Consolidation of hydraulic fluids

The purpose of hydraulic fluid consolidation is to reduce complexity and inventory. Care must be taken to consider all of the critical fluid properties required for each system. Therefore, fluid consolidation must begin at the system level. Consider the following when consolidating liquids:

Determine the specific requirements for each device. Consider all normal operating limitations of your equipment.

Talk to your preferred Lubricants representative. You can collect and share important information about the lubrication needs of your equipment. This ensures that your supplier has all the products you need. Don’t sacrifice system requirements to achieve consolidation.

Also observe the following hydraulic fluid handling procedures.

Implement a procedure for labeling all incoming lubricants and labeling all containers. This minimizes cross-contamination and ensures critical performance requirements are met.

Use a first-in, first-out (FIFO) method in your lubricant storage. A properly designed FIFO system reduces confusion and bearing-related lubricant failure.

Hydraulic systems are sophisticated fluid-based systems for transferring energy and converting that energy into useful work. Successful hydraulic operation requires careful selection of hydraulic fluids that meet system requirements. Viscosity selection is central to proper fluid selection.

There are other important parameters to consider as well, including viscosity index, wear resistance, and oxidation resistance. Liquids can often be consolidated to reduce complexity and material storage costs. Care must be taken not to sacrifice fluid performance to achieve fluid consolidation.

Read more about how to make hydraulics more reliable:

How do you know if you are using the right hydraulic oil?

The benefits of hydraulic fluids with maximum efficiency

The seven most common mistakes in hydraulic equipment

Symptoms of common hydraulic problems and their causes

When oil breaks down, a variety of problems can arise, including gelation. This is when the oil is no longer liquid and resists flowing.

As you can imagine, this leads to poor lubrication and potential machine failure. By understanding what causes gelation and which oils are most susceptible to this process, you can help prevent it and ensure your equipment is running as efficiently as possible.

define gelation

According to ASTM International, oil gelation is defined as a rheological state of an oil characterized by a significant increase in flow resistance beyond the normal exponential increase in viscosity with decreasing temperature, particularly at lower shear stresses and temperatures. ASTM D5133 is a method that can be used to analyze susceptibility to oil gelation.

In this test, a candidate oil is heated and then gradually cooled while measuring viscosity at various temperatures.

The gelation index is a result of this test. As the oil cools, its viscosity increases. This value can be represented in a diagram. The slope of the viscosity line versus temperature is analyzed for changes. If the slope increases rapidly at a certain temperature, this must be taken into account.

Once the test is complete, the entire chart can be analyzed and the gelation index developed. The temperature at which the viscosity thickens rapidly is known as the gelation index temperature.

This information becomes important when temperatures drop, especially if the unit is operating in a cold environment like a freezer, or outside in cold climates. Oils that are most prone to gelation are typically motor oils, especially those with a higher wax content than others (paraffinic base oils).

This phenomenon occurs in colder conditions or in situations where the oil has undergone a gradual cooling. When viscosity increases due to lower temperatures, certain contaminants or conditions can be reached where viscosity increases rapidly and the oil gels.

gelation standards

The American Petroleum Institute (API) has established standards for the gelation index in motor oils. In most cases, the maximum acceptable gelation index is 12 with a maximum viscosity of 40,000 centipoise.

There is a certain point at which an oil simply cannot be pumped anymore due to gelation or too much viscosity. As viscosity increases, a limited flow condition can occur. This occurs when the amount of oil being drawn through the pump is less than is required to properly lubricate the engine.

If the oil gels or the viscosity gets too high, it can lead to another condition known as air-locking. In this condition, an air cavity is created within the oil in the sump. The oil is too thick to fill the cavity and therefore the pump only draws in air.

This has a negative impact on the health of the devices, as it can lead to marginal conditions, excessive wear and tear and eventually premature failure.

Other methods can also be used to test an oil’s cold properties. ASTM D3829 is the standard test method for predicting the limit pumping temperature of engine oil.

This test is about determining the temperature at which an engine oil can no longer be pumped. The test results can provide information as to whether a candidate oil remains fluid enough at certain temperatures or whether a different oil should be selected.

Gelation in gear oils

Gear sets are another area where the gelation or cold properties of an oil become important. Gear oils generally have a high initial viscosity, resulting in a significantly higher viscosity at low temperatures. Studies on gear oils used to lubricate wind turbine gears have shown that these oils can get quite cold several hundred feet off the ground and in cold climates.

The cold temperatures coupled with moisture contamination resulted in the formation of gels in some of the in-service gear oils. This condition can be just as detrimental to the health of the transmission as the engine oil condition discussed earlier.

gelation factors

Several factors should be considered when determining how well a lubricant will perform in colder temperatures and how likely it is to gel at those temperatures. These include the base oil, wax content, pour point and refining process of the base oil. All this significantly affects the gelation and cold properties of the lubricant.

If your equipment operates in extremely cold temperatures, you should consider the base oil used in the lubricant. Mineral base oils have a wide operating temperature range, but are often discarded in favor of comparable synthetic base oil lubricants.

Synthetic oils generally have a higher viscosity index, which means they remain more fluid in cold conditions and thicker in higher temperatures.

For machines that require mineral oils, consider the API base oil category or how refined the base oil is. Crude oils from the ground naturally contain some wax, which can negatively affect the oil’s tendency to gel in cold temperatures.

Most of this wax can be removed by refining. During the dewaxing process, the wax content is reduced or the wax structure is changed to another structure with better properties. The cold properties are also improved. Typically, the more refined a base oil, the higher the viscosity index and the better the low temperature properties.

API base oil groups II and III have lower volatility and lower pour points. If in doubt as to which API group a particular base oil falls into, contact the oil manufacturer or consult the technical data sheets.

The pour point of an oil is another property that should be analyzed before selecting a lubricant for use in cold environments. The pour point is the temperature at which the oil stops flowing due to gravity. When an oil is cooled, the waxes remaining in the oil begin to crystallize and solidify, causing the liquid to become more solid until it stops flowing.

Even oils that are virtually wax-free have a pour point associated with them. When choosing a lubricant for a machine that will operate in extremely cold environments and there are several oils with the same properties other than pour point, choose the one with the lowest pour point to avoid problems related to reduced flow at cold temperatures are.

Synthetic base oils are synthesized from various compounds and usually do not contain waxes. They also have a lower pour point than mineral oils and are often chosen for cold environments due to their higher viscosity index and lower pour points.

However, synthetic base oils are still at risk of gelling when contaminated with certain contaminants such as water and glycol. A routine oil analysis should be performed to look for these common culprits.

prevent gelation

When it is impossible to find an oil that will remain thin enough in cold environments, a common solution to avoiding the pitfalls of restricted flow or excessive viscosity is to install a lube oil heater. These types of heaters can keep the oil warm enough for it to flow and reduce overall system pressure when the oil would otherwise be too thick to pump.

Low wattage heaters, electric blankets and steam lines are popular heating accessories used to keep the oil at a constant temperature. If you plan to use a heater, make sure it doesn’t heat the oil too much as this can break down the oil and shorten its life. If steam is used, the oil should be routinely inspected for water ingress.

advantages of gelation

An oil’s tendency to gel at certain temperatures and with certain contaminants isn’t always a bad thing. In fact, this property has been used in cleaning up spilled oil, especially oils spilled in large bodies of water. The Environmental Protection Agency uses “gelling agents” to form gels in spilled oil without reacting with the water.

These agents are mixed into the oil slick by mechanical agitation or by the action of the waves in the body of water. Once the oil has gelled, the agents can be easily removed by skimming or any other form of separation.

While not all oils behave the same when faced with contamination and cold temperatures, most problems associated with lubricant thickening can be avoided with a good contamination control program and by selecting the right lubricant for the application.

Routine oil analysis can help identify problems related to oil gelation before significant machine damage occurs. If temperature control equipment such as heaters must be used, check them frequently for signs of failure.

Also check the oil temperature to avoid overheating. With the right attention and care, the lubes you use in cold temperatures can provide long service life with little if any trouble.

According to a recent survey on MachineryLubrication.com, 36% of lubricant professionals have seen the effects of oil gelation in machinery at their facility

About the author

Fluids play a key role in hydraulic systems. In fact, every operation requires hydraulic fluid within the hydraulic system.

These fluids can be affected by environmental changes such as temperature changes. Therefore, the entire hydraulic system can be affected.

As temperatures rise, hydraulic fluid can begin to evaporate. When temperatures drop, the liquid can freeze. This is one of the main concerns when we consider hydraulic fluids and climatic changes.

Hydraulic systems can power small objects like toys to large applications like airplanes or mechanical robotics.

In many of these cases there will be times when the applications will come into contact with sources of ignition and very hot surfaces.

Some examples of applications that come into contact with higher temperatures and sources of ignition are pig iron shears, coke oven door openers and furnace loaders and unloaders.

Such applications leave the question unanswered: what happens when the hydraulic fluid is exposed to high temperature situations and hydraulic fluid is flammable? Well, that generally depends on the type of hydraulic fluid used.

Hydraulic fluids are considered serious fire hazards due to their high ignition temperatures. If hydraulic oil is sprayed around an area, it can burn just as fiercely as other hydrocarbons.

Today we will discuss hydraulic fluid flammability and its safety in specific applications. Read on for more information on using such liquids.

What is a hydraulic system?

A hydraulic power system consists of hydraulic fluid and three important mechanical components. These are considered pressure generators or hydraulic pumps and can be powered by an electric motor or a manual pump/motor.

The system consists of valves, pipes, filters, where the motor can be hydraulic, a hydraulic cylinder or a hydraulic actuator.

Almost all aircraft use some form of hydraulic system. The hydraulic components of a general aviation aircraft are usually limited to its wheel brakes.

In larger aircraft, the hydraulic system can provide the motive power for other systems such as landing gear retraction and extension, nosewheel steering, flight controls actuation, emergency power generation, and more.

As you can imagine, the risk of fire from hydraulic fluids is a serious concern. A hydraulic fluid fire can result in the loss of an aircraft or machine and, in the worst case, loss of life.

Categories of hydraulic fluids

As previously mentioned, there are different categories of hydraulic fluids. These are:

mineral oils

Fire Resistant Liquids

water/oil emulsions

water glycol

phosphate ester

Petroleum-based hydraulic fluids, such as mineral oils, have a flash point in the 300 to 600 degree Fahrenheit range. The flash point is the lowest temperature at which vapors can ignite.

Water-based hydraulic fluids are flammable. However, a corrosion problem can arise when using these types of fluids. To test how flammable hydraulic fluids are, research is being done depending on the ISO 12922 specification.

Fire-resistant hydraulic fluids are typically classified as oil-water emulsions, water-free plastics, and water-polymer solutions.

Flame retardant hydraulic fluids that contain water have a water content of more than 35%. ISO 12922:2012 classifies these into:

HFAE

HFAS

HFB

HFC

HFDR

HFDU

HFAE – Hydraulic fluids in this category are considered oil-in-water emulsions. They have a milky to translucent emulsion appearance. These liquids contain more than 80% water and are resistant to aging. HFAE has applications in mine support, underground hydraulic strut extensions and hydrostatic drives.

HFAS – These are synthetic aqueous liquids that are transparent in appearance. These fluids are free of mineral oils and contain more than 80% water. The main applications of HFAS are mine support, press hydraulics, foundry engineering and many more.

HFB – HFB fluid is a water-in-oil emulsion containing more than 40% water. One application of this is in coal mining. The minimum ignition temperature (flash point) of HFB is 1,202 degrees Fahrenheit or 650 degrees Celsius according to ISO standards.

HFC – This is known as glycol solutions, polyalkylene glycol solutions, or water glycols. The flash point of this liquid is 1,112 degrees Fahrenheit or 600 degrees Celsius. It is a water-polymer solution containing more than 35% water.

It has applications where waterless hydraulics are not used. This includes the steel industry, foundries, coking plants, hardening shops, injection molding, press forming and more.

HFDR – This uses phosphoric acid esters. It tends to have poor viscosity as well as poor temperature properties. HFDR is considered a hazardous material because it can emit toxic gases in the event of a fire. One application that uses HFDR is the turbine control system.

HFDU – HFDU can be categorized into ester based and glycol based. Glycol-based HFDU generally has good viscosity, good temperature properties, shear stability, and is resistant to aging. It is a water soluble liquid with excellent anti-wear properties.

Mobile systems with high thermal load characteristics use glycol-based HFDU, while ester-based HFDU has a higher dirt-dissolving capacity.

So is hydraulic fluid flammable?

Hydraulic fluid is extremely flammable. It has been a factor in many fires over the years and if caught fire can greatly increase the extent of fire damage.

Hydraulic systems are under high pressure. This allows the flames of a hydraulic oil fire to spread over long distances.

In factory settings, these flames can easily reach cables and other combustible materials, which quickly catch fire and are quickly destroyed.

It is therefore important that you assess the risks associated with hydraulic oils so that you and others are protected at all times.

The risk of a hydraulic oil fire can actually be eliminated by converting non-flammable hydraulic fluids or by using electrically or pneumatically operated equipment instead.

in summary

Hydraulic fluid can be extremely flammable due to its high flash point. Some of these liquids are more susceptible to fire than others due to their properties and water content.

However, sufficient and appropriate care should be taken whenever hydraulic fluids are used or nearby. With preventive measures, catastrophic fires can be avoided.

Related:

If the hydraulic oil turns from the golden honey color of the new oil to a dark brown, does that mean it needs to be changed immediately? In this case, does the system suffer from loss of lubricating properties or gross contamination, or is this a normal aging feature that must be discarded as long as the oil analysis results are within acceptable parameters?

These types of questions are often asked when it comes to hydraulic fluid maintenance. Many people compare the oil in their industrial hydraulic systems to that in their car and assume that a dark brown oil needs changing as soon as possible, regardless of how long it has been in service.

It’s easy to forget that the oil in an industrial hydraulic system is kept in a very different environment than the oil in an internal combustion engine. A color change in the hydraulic oil is a good reason to be alert, but not a good reason to rush out to replace the oil skid. You must first determine why the oil changed color.

The two most common causes of oil darkening are thermal stress and oxidation, neither of which necessarily require an oil change. In the first step, a representative sample of the oil is taken and analyzed. I’ve seen hydraulic oil that has darkened badly but was still perfectly fine to stay in service. I’ve also seen hydraulic oil that retained its original color but failed to meet the parameters needed for adequate system protection. In short, a change in oil color alone is not indicative of the oil’s serviceability.

However, a darkening of the oil can alert you to potential problems that may need to be addressed. A system may have one or more ‘hot spots’ where the oil is greatly heated in a localized area, but the temperature drops again once it reaches the relatively cool reservoir.

I once found a valve that had failed and was forcing oil through a small orifice with a significant drop in pressure. This generated a relatively large amount of heat, but it was only localized in a very small amount of the system oil. The only symptom was a darkening of the oil.

When a sample of the oil was analyzed, it was found that the acid number and viscosity had not changed, ruling out the possibility of oil oxidation and suggesting that the color change was the result of thermal degradation. The inspection with an infrared camera localized the overheating valve in a very short time. The valve was replaced and significant varnish was found where the heat was generated.

Oil analysis showed that the oil was perfectly suitable for continued operation, but since there was no discernible change in system operation, if there had not been a color change in the oil, the valve failure might have gone unnoticed until system failure occurred.

While oxidation, the chemical union of oil and oxygen, is a common reason hydraulic oil stability is reduced, the extent of the color change is not a good indication of the degree of oxidation. Antioxidants react as they do their job, often creating colors ranging from bright yellow to deep black. There are a number of factors, including formulation, operating conditions and contaminants, any of which can cause a significant color change without significant oil degradation.

Although the color change can be alarming, the oil can still retain good antioxidant potential as a number of these reactions can occur before it is truly depleted. Here, too, the only way to reliably determine the degree of oxidation is to analyze the oil. Look for an increase in viscosity and acid number of the oil as an indication of oxidation.

The presence of metal catalyst particles, heat, oxygen and water all contribute to oil oxidation. As acidity increases, component corrosion becomes more likely. Viscosity increases as soluble contaminants mix with the oil. This leaves deposits of sludge, varnish and tar as a thin, insoluble film on the internal surfaces of the system. The degradation process accelerates with continued exposure to these elements.

Oxidation can be kept to a minimum through normal maintenance practices. The rate of all chemical reactions, including oxidation, will roughly double for every 10 degrees C (18 degrees F) increase in temperature. For most petroleum based hydraulic systems, the maximum recommended temperature is 60°C (140°F). Oil life is halved for every 15 degrees F (5 degrees C) above this temperature.

System pressure can also make a difference. As the pressure increases, the fluid viscosity also increases, leading to an increase in friction and heat generation. In addition, increased pressure leads to an increase in entrained air (and therefore oxygen). The extra oxygen speeds up the oxidation reaction of the oil. It is recommended that system pressure be kept as low as possible for maximum system efficiency and longevity of the oil and system components.

Impurities are another factor that can affect oxidation. A 1% concentration of sludge in the hydraulic fluid doubles the rate of oxidation compared to fluids without any sludge. Certain metals, especially copper, act as catalysts for oxidation reactions, especially in the presence of water. The presence of water and copper is common when a heat exchanger cracks.

If you find your hydraulic oil has changed color, don’t assume it needs to be replaced. It’s very likely that your liquid has years of service left in it. Get a good representative sample and have it analyzed. The most representative sample is taken immediately after the pump. The second best position is the exact center of the reservoir, obtained either during operation or immediately after shutdown.

If you’re just beginning a fluid removal program, every 13 weeks is a good place to start. Adjust sampling frequency based on analysis results. Retain analytics for at least a full year to compare and identify trends. Only then do you really know the condition and serviceability of your hydraulic fluid.

Read more about best practices for hydraulic systems:

10 Hydraulic Reliability Checks You Probably Don’t Do

The seven most common mistakes in hydraulic equipment

How do you know if you are using the right hydraulic oil?

Top 5 hydraulic errors and best solutions

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