typical hydraulic pump efficiency factory

In a condition-based maintenance environment, the decision to change out a hydraulic pump or motor is usually based on remaining bearing life or deteriorating efficiency, whichever occurs first.

Despite recent advances in predictive maintenance technologies, the maintenance professional’s ability to determine the remaining bearing life of a pump or motor, with a high degree of accuracy, remains elusive.

Deteriorating efficiency on the other hand is easy to detect, because it typically shows itself through increased cycle times. In other words, the machine slows down. When this occurs, quantification of the efficiency loss isn’t always necessary. If the machine slows to the point where its cycle time is unacceptably slow, the pump or motor is replaced. End of story.

In certain situations, however, it can be helpful, even necessary, to quantify the pump or motor’s actual efficiency and compare it to the component’s native efficiency. For this, an understanding of hydraulic pump and motor efficiency ratings is essential.

There are three categories of efficiency used to describe hydraulic pumps (and motors): volumetric efficiency, mechanical/hydraulic efficiency and overall efficiency.

Volumetric efficiency is determined by dividing the actual flow delivered by a pump at a given pressure by its theoretical flow. Theoreticalflow is calculated by multiplying the pump’s displacement per revolution by its driven speed. So if the pump has a displacement of 100 cc/rev and is being driven at 1000 RPM, its theoretical flow is 100 liters/minute.

Actualflow has to be measured using a flow meter. If when tested, the above pump had an actual flow of 90 liters/minute at 207 bar (3000 PSI), we can say the pump has a volumetric efficiency of 90% at 207 bar (90 / 100 x 100 = 90%).

Its volumetric efficiency used most in the field to determine the condition of a hydraulic pump - based on its increase in internal leakage through wear or damage. But without reference to theoretical flow, the actual flow measured by the flow meter would be meaningless.

A pump’s mechanical/hydraulic efficiency is determined by dividing thetheoretical torque required to drive it by the actual torque required to drive it. A mechanical/hydraulic efficiency of 100 percent would mean if the pump was delivering flow at zero pressure, no force or torque would be required to drive it. Intuitively, we know this is not possible, due to mechanical and fluid friction.

Table 1. The typical overall efficiencies of hydraulic pumps, as shown above, are simply the product of volumetric and mechanical/hydraulic efficiency.Source: Bosch Rexroth

Like theoretical flow, theoretical drive torque can be calculated. For the above pump, in SI units: 100 cc/rev x 207 bar / 20 x p = 329 Newton meters. But like actual flow, actual drive torque must be measured and this requires the use of a dynamometer. Not something we can - or need - to do in the field. For the purposes of this example though, assume the actual drive torque was 360 Nm. Mechanical efficiency would be 91% (329 / 360 x 100 = 91%).

Overall efficiency is simply the product of volumetric and mechanical/hydraulic efficiency. Continuing with the above example, the overall efficiency of the pump is 0.9 x 0.91 x 100 = 82%. Typical overall efficiencies for different types of hydraulic pumps are shown in the Table 1.

System designers use the pump manufacturers’ volumetric efficiency value to calculate the actual flow a pump of a given displacement, operating at a particular pressure, will deliver.

As already mentioned, volumetric efficiency is used in the field to assess the condition of a pump, based on the increase in internal leakage due to wear or damage.

When calculating volumetric efficiency based on actual flow testing, it’s important to be aware that the various leakage paths within the pump are usually constant. This means if pump flow is tested at less than full displacement (or maximum RPM) this will skew the calculated efficiency - unless leakage is treated as a constant and a necessary adjustment made.

For example, consider a variable displacement pump with a maximum flow rate of 100 liters/minute. If it was flow tested at full displacement and the measured flow rate was 90 liters/minute, the calculated volumetric efficiency would be 90 percent (90/100 x 100). But if the same pump was flow tested at the same pressure and oil temperature but at half displacement (50 L/min), the leakage losses would still be 10 liters/minute, and so the calculated volumetric efficiency would be 80 percent (40/50 x 100).

The second calculation is not actually wrong, but it requires qualification: this pump is 80 percent efficient at half displacement. Because the leakage losses of 10 liters/minute are nearly constant, the same pump tested under the same conditions will be 90 percent efficient at 100 percent displacement (100 L/min) - and 0 percent efficient at 10 percent displacement (10 L/min).

To help understand why pump leakage at a given pressure and temperature is virtually constant, think of the various leakage paths as fixed orifices. The rate of flow through an orifice is dependant on the diameter (and shape) of the orifice, the pressure drop across it and fluid viscosity. This means that if these variables remain constant, the rate of internal leakage remains constant, independent of the pump"s displacement or shaft speed.

Overall efficiency is used to calculate the drive power required by a pump at a given flow and pressure. For example, using the overall efficiencies from the table above, let us calculate the required drive power for an external gear pump and a bent axis piston pump at a flow of 90 liters/minute at 207 bar:

As you’d expect, the more efficient pump requires less drive power for the same output flow and pressure. With a little more math, we can quickly calculate the heat load of each pump:

No surprise that a system with gear pumps and motors requires a bigger heat exchanger than an equivalent (all other things equal) system comprising piston pumps and motors.

Hydraulic pumps convert mechanical energy into hydraulic energy. A high-performance piston pump can convert mechanical energy into hydraulic energy with an efficiency of 92 percent.

If the pump drives a piston motor, the motor is able to convert this hydraulic energy back into mechanical energy with an efficiency of 92 percent. The overall efficiency of this hydraulic drive, without considering flow losses, is 85 percent (0.92 x 0.92 x 100 = 85).

The inefficiencies or losses in a hydraulic drive can be divided into two categories: hydraulic-mechanical, which comprise flow and mechanical friction losses, and volumetric, which comprise leakage and compressibility losses (Figure 1).

The advantages of a hydraulic drive, which include high-power density (high-power output per unit mass), variable speed control, simple overload protection and both rotary and linear motion, are possible from a single system.

As Table 1 shows, a key disadvantage of a hydraulic drive is that it is far less efficient than a mechanical drive. What’s worse, the wear process decreases a hydraulic drive’s volumetric efficiency (and therefore total efficiency) causing the drive to slow down and more energy to be given up to heat.

The hydraulic pump is usually the hardest working component of a hydraulic system. As the pump wears in service, internal leakage increases and therefore the percentage of theoretical flow available to do useful work (volumetric efficiency) decreases. If volumetric efficiency falls below a level considered acceptable for the application, the pump will need to be overhauled.

In a condition-based maintenance environment, the decision to change-out the pump is often based on remaining bearing life or deterioration in volumetric efficiency, whichever occurs first.

Volumetric efficiency is the percentage of theoretical pump flow available to do useful work. In other words, it is a measure of a hydraulic pump’s volumetric losses through internal leakage and fluid compression. It is calculated by dividing the pump’s actual output in liters or gallons per minute by its theoretical output, expressed as a percentage. Actual output is determined using a flow-tester to load the pump and measure its flow rate.

Because internal leakage increases as operating pressure increases and fluid viscosity decreases, these variables should be included when stating volumetric efficiency. For example, a hydraulic pump with a theoretical output of 100 GPM, and an actual output of 94 GPM at 5,000 PSI and 46 cSt is said to have a volumetric efficiency of 94 percent at 5,000 PSI and 46 cSt.

In practice, fluid viscosity is established by noting the fluid temperature at which actual pump output is measured and reading the viscosity off the temperature/viscosity graph for the grade of fluid in the hydraulic system.

When calculating the volumetric efficiency of a variable displacement pump, internal leakage must be expressed as a constant. Consider this example: I was recently asked to give a second opinion on the condition of a large, variable displacement pump. My client had been advised that its volumetric efficiency was down to 80 percent and based on this advice, he was considering having the pump overhauled.

The hydraulic pump in question had a theoretical output of 1,000 liters per minute at full displacement and maximum rpm. Its actual output was 920 liters per minute at 4,350 PSI and 46 cSt. When I advised my client that the pump’s volumetric efficiency was in fact 92 percent he was alarmed by the conflicting assessments. To explain the disparity, I asked to see the first technician’s test report.

The technician had limited the pump’s displacement to give an output of 400 liters per minute (presumably the maximum capacity of his flow-tester) at maximum rpm and no load. At 4,350 PSI the recorded output was 320 liters per minute. From these results, volumetric efficiency had been calculated to be 80 percent (320/400 x 100 = 80).

To help understand why this interpretation is incorrect, think of the various leakage paths within a hydraulic pump as fixed orifices. The rate of flow through an orifice is dependent on the diameter (and shape) of the orifice, the pressure drop across it and fluid viscosity. This means that if these variables remain constant, the rate of internal leakage remains constant, independent of the pump’s displacement.

Note that in the above example, the internal leakage in both tests was 80 liters per minute. If the same test was conducted with pump displacement set to 100 liters per minute at no load, pump output would be 20 liters per minute at 4,350 PSI - all other things equal.

This means that this pump has a volumetric efficiency of 20 percent at 10 percent displacement, 80 percent at 40 percent displacement and 92 percent at 100 percent displacement. As you can see, if actual pump output is measured at less-than-full displacement (or maximum rpm), an adjustment needs to be made when calculating volumetric efficiency.

In considering whether it is necessary to have this hydraulic pump overhauled, the important number is volumetric efficiency at 100 percent displacement, which is within acceptable limits. If my client had based his decision on volumetric efficiency at 40 percent displacement, his company would have paid thousands of dollars for unnecessary repairs.

Studies reveal that efficiencies of industrial hydraulic systems range from <9% to 60% efficient, and average efficiency was 22%. So on average, the cost of wasted energy is $24.3 billion. Improving efficiency of industrial hydraulics by just an additional 10% would result in savings of approximately $3 billion per year.

Efficiency is the ratio of output power to input power. For example, if a hydraulic components and system can transmit 100 hp out for some work process, but because of inefficiencies in the system it requires 125 hp of input from a prime mover, then the hydraulic system is 80% efficient.

The good news is there are many opportunities to improve efficiency and garner substantial energy and cost savings. Start with an understanding of the system operation and by reviewing schematics. Ask yourself, what areas are inefficient in their use of energy during operation? The key is analyzing the design’s required output power versus input power.

Reservoirs. Beware of rules of thumb that result in sizing the reservoir too large. Standard practice is three times the pump flow. But the primary reason given is to remove heat, which is a myth. The reservoir is not an effective heat sink and requires an extremely large size to dissipate typical heat, unless duty cycle is low.

Prime movers. Review the current electric-motor design and decide if the return on investment for energy savings would justify replacing the current unit with a premium high-efficiency motor. And it may be better for overall operation of the system to retrofit with a variable-speed drive. Except for applications where the pump-motor combination runs continuously at a constant speed, a VFD can often quickly pay for itself with sizable energy savings.

The Energy Independence and Security Act of 2007 (EISA) raised to a premium level the mandatory minimum nominal full-load efficiency for general-purpose motors rated below 1,000 V and up to 200 hp. For example, the previous standard efficiency for a 10 hp motor was 86.7% and the new minimum efficiency level is 92.2%. Minimum efficiency for motors greater than 200 hp is 96%. However, keep in mind that a 1% increase in efficiency for a 100 hp motor will result in more cost savings than a 9% increase in efficiency of a 10 hp motor.

The flow source (pump).Depending on the design and operation, efficiency can vary significantly from one type of pump to another. Analyze the overall efficiency of the hydraulic pump and the control method used, and evaluate your ROI to determine if it is justified to change to a more-efficient system.

Analyze dwell times, if any exist, and determine how to minimize energy use during this time. Among the possibilities: add an accumulator, unload the pump, select a variable-speed drive, or upgrade the pump controls. Using RMS power calculations helps determine if the prime mover can be downsized, which will reduce overall energy consumption during dwell times. Also, analyze pump displacement and determine if it is properly sized for the energy demand.

Evaluate the fluid.Determine fluid requirements, for example the viscosity, based on the application and system components. Two areas that primarily impact pumps and motors are volumetric efficiency and hydromechanical efficiency. There is a viscosity range where fluid friction, mechanical friction and volumetric losses are minimized and optimal for hydraulic system performance. This is the viscosity range where the hydraulic system will operate most efficiently — the highest ratio of output power to input power.

A study published in Machinery Lubrication magazine showed that by using high Viscosity Index fluids, typical cost savings per vane pump in mobile hydraulic systems was approximately $400 per year. Mobil Corp. conducted a study on a typical ISO VG 46 fluid versus a high VI fluid at the same viscosity grade and showed efficiency improvements of 3 to 6% due to the fluid alone.

In-plant savings would be typically less as the temperature of fluids used in industrial systems is much more regulated and consistent, although during cold start-ups or high temperature operations, savings would be realized in industrial systems through high VI fluids.

Fluid conductor sizing.Pressure drop caused by frictional losses in fluid conductors is a significant source of wasted energy in a typical hydraulic system. Designers attempt to balance pressure drop against the cost of conductors and, in most cases, reduce the size of conductors to lower initial system cost without regard to total operating cost due to wasted energy.

So circuit designers should avoid extra fittings, sharp bends and undersized inner diameters of conductors — especially for pump inlets to avoid cavitation. In the pump inlet line, it is recommended that a straight length of at least 10 times the inner diameter of the fluid conductor be established directly prior to the pump inlet to allow for a transition back to laminar flow and minimize potential cavitation.

Undersized valves can also lead to increased energy loss due to throttling effects and friction (heat). Improperly sized pressure controls can have excessive pressure override which also results in energy waste and reduces efficiency.

Contamination control. To ensure a high-performing and reliable hydraulic system, engineers should determine the target cleanliness level, evaluate the contamination control system, and sample fluid regularly and look for evidence of oxidation.

Proper filtration and contamination control is essential for energy efficient systems. Improper contamination control leads to many consequences, none of them good. It results in increased component wear, with more internal leakage and wasted energy. It changes fluid viscosity which impacts efficiency as described previously.

Heat is also a contaminant, as it accelerates degradation (oxidation) of the fluid and impacts system efficiency. Lack of contamination control can result in valves partially opening and increasing throttling losses. Likewise, excessive air is another contaminant in the fluid, and it can affect heat transfer rates and damage pumps.

Actuator selection. Evaluate seal choice because internal friction results in energy loss. Different materials, types and designs can have a noticeable impact on dynamic seal performance and efficiency. Also evaluate the condition of internal seals, as damaged seals permit leakage which generates heat and wastes energy.

Look for the presence of a heat exchanger, and analyze its size compared to a typical unit based on size of the system. A cooler rated at higher than 30% of overall system horsepower could be indicator of energy inefficiencies that should be addressed.

Which pump you choose for your power unit affects the nature of your HPU builds. Pump choice usually depends on cost, complexity, and performance. There are three major types of pumps to select from: the gear pump, the piston pump, and the vane pump. Below, we’ll get into the specifics of each pump to help you make the best decision for your system.

Gear pumps are usually very economical but hold lower efficiency values. Their efficiency typically drops over time. However, they are quite durable. A pump’s job is to convert incoming mechanical energy into hydraulic energy. The more efficient the pump, the smaller the motor you can choose. Efficiency saves you the most money over time. Traditional spur gear pumps an average of about 80% efficiency, which puts you at a disadvantage over time.

Vane pumps fall between gear pumps and piston pumps when it comes to practicality. They’re more efficient than gear pumps but less efficient than piston pumps. Vane pumps are known for being very quiet, making them ideal for industrial applications. They’re also available with a myriad of control options, like pressure compensation, displacement control, and load sensing. However, Vane pumps usually can’t handle high-pressure circuits.

Piston pumps account for the premium end of the range. These pumps are capable of supporting very high pressure and have infinite methods of control, including pressure compensation, servo control, load sensing, horsepower control, and more. Piston pumps are also incredibly efficient, with many designs being capable of 95% efficiency. The biggest downside to choosing a piston pump is cost. The initial investment will be pricey, and service or repair can be costly as well.

If you’d like more information about choosing the best pump for your HPU design, contact GCC, Inc. today! Our team of experts is ready to help you find a pump that suits your needs.

If you have read news about pumps and motors in the last 10 years, you know there is increasing pressure to create more efficient pumps. The pump energy saving initiatives are similar to what has transpired over the last 15 years with alternating current (AC) electric motor design.

Starting in 2011, and coming to fruition in 2020, the United States Department of Energy (DOE) placed requirements (regulations) on centrifugal water pumps to meet minimum efficiency levels. Some of this work started in the 1990s, but the regulations (“Energy Conservation Standards for Pumps”) came years later.

The Hydraulic Institute (HI) has initiated numerous programs, ranging from public awareness to in-depth training and management guides. As their website states, “HI has taken a leading role in representing the pump industry in negotiating fair and appropriate regulations designed to achieve energy savings goals.”

I was recently contacted by an engineering college for my input on designing more efficient pumps. I eagerly prepared for the meeting, but the project was canceled due to the COVID-19 pandemic. Afterwards, like a really bad marketing jingle, I couldn’t get the topic of pump efficiency out of my brain. Ideas for improving efficiency replayed in my head in a pedantic voice burned into my cortex by my paternal grandmother: “Easier said than done,” and “You can’t get something for nothing,” played in a continuous loop.

For the record, I think higher efficiency is both a commendable goal and a high priority in my work. In conflict with this goal, my personal opinion is that if you don’t design the associated pumping system correctly and operate the pump properly, it doesn’t matter if the pump is efficient or not. The pump and the system must work together—one needs the other.

The basic definition of efficiency is a simple formula. Efficiency is the ratio of output divided by the input and then multiplied by 100 to express it as a percentage.

If your vehicle has a gasoline engine, it is about 20 percent efficient; if the engine is diesel, it may improve to 30 percent or more. The efficiency of a coal-fired or nuclear power plant can approach 38 percent. Gas-fired power plants with a combined cycle can approach 60 percent. Modern AC induction motors have recently approached 99 percent efficiency, but most often are 91 percent to 95 percent at near full load conditions.

Centrifugal pumps can approach 94 percent efficiency, but typical efficiencies are 55 percent for small pumps and 70 percent for large pumps. The amount of electrical energy used by the pumps in an average industrial facility will vary by plant type. A typical pulp and paper mill will use 30 percent of their energy usage to drive pumps. A chemical plant may use 27 percent and a petroleum refinery may use 60 percent. Over a short time, the cost of the energy to drive the pump will exceed the initial purchasing and installation costs. Over a 20-year period, it is common for the energy costs of a typical 100-horsepower pump to exceed 20 times the initial cost of the pump, including installation.

Pump efficiency is the “water horsepower” divided by the “brake horsepower” and multiplied by 100 to present it as a percentage (see formulas in Image 1).

Water horsepower is a system design tool and is the power that the pump would require to accomplish the hydraulic conditions if it was 100 percent efficient. The efficiency of the pump is not a factor in the water horsepower equation. Water horsepower defines the lowest boundary for the power requirements. Or, think of it as the minimum power required to move the fluid (water). This is handy information to have in the early stages of a plant design. Note that the specific gravity should be used when doing this calculation.

Brake horsepower (BHP) is the shaft horsepower the pump requires to meet the load. Brake horsepower takes pump efficiency into account, but not the motor efficiency. This data is used to size the driver. Pump input horsepower and efficiency can be calculated from the basic BHP formula, but when preparing the performance curves, the manufacturer will measure the speed and torque of the motor shaft input to the pump. The pump efficiency is a simple calculation once you have the speed and torque data.

Wire-to-water efficiency is the amount of energy that is imparted to the pumped fluid (water) divided by the energy that was introduced by the electrical system—or the work completed divided by the work applied. When using fractions or decimals, we can multiply in lieu of dividing, and so the wire-to-water efficiency is the pump efficiency multiplied by the motor efficiency. This information allows us to properly size the electrical service to the motor. (Wire-to-water efficiency is referred to as wire-to-liquid efficiency if the fluid is not water.)

For example, a motor that is 90 percent efficient that is driving a 70 percent efficient pump produces a real efficiency of 63 percent (0.90 x 0.70 = 0.63 or 63 percent efficient). Note: it is not the average efficiency of the two factors, which is a common mistake. Wire-to-water efficiency becomes a major factor and is an important tool when calculating the power cost for pumping a specific amount of liquid.

Some factors preventing the pump from obtaining higher efficiency are noise, vibration, recirculation and heat. Other impediments to pump efficiency include:

Mechanical efficiency factors, which are mostly frictional losses from bearings, packing, mechanical seals, impeller/rotor imbalance, couplings and driver misalignment.

Volumetric efficiency is the sum of the losses from leakage across wear rings, impeller clearance to casing, interstage bushings, balance drums, warm-up/bypass lines and internal flow back to the stuffing box/lantern ring.

Hydraulic efficiency factors are the largest hindrance. This is the sum of all the fluid friction losses in the pump, including disc friction and hydraulic shock losses. Shock losses are due to the rapid acceleration and deceleration of the fluid, which are greater at low flow rates and are a function of impeller geometry. The shock factor is why high specific speed impellers will typically be more efficient.

Calculation of preliminary cooler capacity: Heat dissipation from hydraulic oil tanks, valves, pipes and hydraulic components is less than a few percent in standard mobile equipment and the cooler capacity must include some margins. Minimum cooler capacity, Ecooler = 0.25Ediesel

At least 25% of the input power must be dissipated by the cooler when peak power is utilized for long periods. In normal case however, the peak power is used for only short periods, thus the actual cooler capacity required might be considerably less. The oil volume in the hydraulic tank is also acting as a heat accumulator when peak power is used.

The system efficiency is very much dependent on the type of hydraulic work tool equipment, the hydraulic pumps and motors used and power input to the hydraulics may vary considerably. Each circuit must be evaluated and the load cycle estimated. New or modified systems must always be tested in practical work, covering all possible load cycles.

Hydraulic pumps are mechanisms in hydraulic systems that move hydraulic fluid from point to point initiating the production of hydraulic power. Hydraulic pumps are sometimes incorrectly referred to as “hydrolic” pumps.

They are an important device overall in the hydraulics field, a special kind of power transmission which controls the energy which moving fluids transmit while under pressure and change into mechanical energy. Other kinds of pumps utilized to transmit hydraulic fluids could also be referred to as hydraulic pumps. There is a wide range of contexts in which hydraulic systems are applied, hence they are very important in many commercial, industrial, and consumer utilities.

“Power transmission” alludes to the complete procedure of technologically changing energy into a beneficial form for practical applications. Mechanical power, electrical power, and fluid power are the three major branches that make up the power transmission field. Fluid power covers the usage of moving gas and moving fluids for the transmission of power. Hydraulics are then considered as a sub category of fluid power that focuses on fluid use in opposition to gas use. The other fluid power field is known as pneumatics and it’s focused on the storage and release of energy with compressed gas.

"Pascal"s Law" applies to confined liquids. Thus, in order for liquids to act hydraulically, they must be contained within a system. A hydraulic power pack or hydraulic power unit is a confined mechanical system that utilizes liquid hydraulically. Despite the fact that specific operating systems vary, all hydraulic power units share the same basic components. A reservoir, valves, a piping/tubing system, a pump, and actuators are examples of these components. Similarly, despite their versatility and adaptability, these mechanisms work together in related operating processes at the heart of all hydraulic power packs.

The hydraulic reservoir"s function is to hold a volume of liquid, transfer heat from the system, permit solid pollutants to settle, and aid in releasing moisture and air from the liquid.

Mechanical energy is changed to hydraulic energy by the hydraulic pump. This is accomplished through the movement of liquid, which serves as the transmission medium. All hydraulic pumps operate on the same basic principle of dispensing fluid volume against a resistive load or pressure.

Hydraulic valves are utilized to start, stop, and direct liquid flow in a system. Hydraulic valves are made of spools or poppets and can be actuated hydraulically, pneumatically, manually, electrically, or mechanically.

The end result of Pascal"s law is hydraulic actuators. This is the point at which hydraulic energy is transformed back to mechanical energy. This can be accomplished by using a hydraulic cylinder to transform hydraulic energy into linear movement and work or a hydraulic motor to transform hydraulic energy into rotational motion and work. Hydraulic motors and hydraulic cylinders, like hydraulic pumps, have various subtypes, each meant for specific design use.

The essence of hydraulics can be found in a fundamental physical fact: fluids are incompressible. (As a result, fluids more closely resemble solids than compressible gasses) The incompressible essence of fluid allows it to transfer force and speed very efficiently. This fact is summed up by a variant of "Pascal"s Principle," which states that virtually all pressure enforced on any part of a fluid is transferred to every other part of the fluid. This scientific principle states, in other words, that pressure applied to a fluid transmits equally in all directions.

Furthermore, the force transferred through a fluid has the ability to multiply as it moves. In a slightly more abstract sense, because fluids are incompressible, pressurized fluids should keep a consistent pressure just as they move. Pressure is defined mathematically as a force acting per particular area unit (P = F/A). A simplified version of this equation shows that force is the product of area and pressure (F = P x A). Thus, by varying the size or area of various parts inside a hydraulic system, the force acting inside the pump can be adjusted accordingly (to either greater or lesser). The need for pressure to remain constant is what causes force and area to mirror each other (on the basis of either shrinking or growing). A hydraulic system with a piston five times larger than a second piston can demonstrate this force-area relationship. When a force (e.g., 50lbs) is exerted on the smaller piston, it is multiplied by five (e.g., 250 lbs) and transmitted to the larger piston via the hydraulic system.

Hydraulics is built on fluids’ chemical properties and the physical relationship between pressure, area, and force. Overall, hydraulic applications allow human operators to generate and exert immense mechanical force with little to no physical effort. Within hydraulic systems, both oil and water are used to transmit power. The use of oil, on the other hand, is far more common, owing in part to its extremely incompressible nature.

Pressure relief valves prevent excess pressure by regulating the actuators’ output and redirecting liquid back to the reservoir when necessary. Directional control valves are used to change the size and direction of hydraulic fluid flow.

While hydraulic power transmission is remarkably useful in a wide range of professional applications, relying solely on one type of power transmission is generally unwise. On the contrary, the most efficient strategy is to combine a wide range of power transmissions (pneumatic, hydraulic, mechanical, and electrical). As a result, hydraulic systems must be carefully embedded into an overall power transmission strategy for the specific commercial application. It is necessary to invest in locating trustworthy and skilled hydraulic manufacturers/suppliers who can aid in the development and implementation of an overall hydraulic strategy.

The intended use of a hydraulic pump must be considered when selecting a specific type. This is significant because some pumps may only perform one function, whereas others allow for greater flexibility.

The pump"s material composition must also be considered in the application context. The cylinders, pistons, and gears are frequently made of long-lasting materials like aluminum, stainless steel, or steel that can withstand the continuous wear of repeated pumping. The materials must be able to withstand not only the process but also the hydraulic fluids. Composite fluids frequently contain oils, polyalkylene glycols, esters, butanol, and corrosion inhibitors (though water is used in some instances). The operating temperature, flash point, and viscosity of these fluids differ.

In addition to material, manufacturers must compare hydraulic pump operating specifications to make sure that intended utilization does not exceed pump abilities. The many variables in hydraulic pump functionality include maximum operating pressure, continuous operating pressure, horsepower, operating speed, power source, pump weight, and maximum fluid flow. Standard measurements like length, rod extension, and diameter should be compared as well. Because hydraulic pumps are used in lifts, cranes, motors, and other heavy machinery, they must meet strict operating specifications.

It is critical to recall that the overall power generated by any hydraulic drive system is influenced by various inefficiencies that must be considered in order to get the most out of the system. The presence of air bubbles within a hydraulic drive, for example, is known for changing the direction of the energy flow inside the system (since energy is wasted on the way to the actuators on bubble compression). Using a hydraulic drive system requires identifying shortfalls and selecting the best parts to mitigate their effects. A hydraulic pump is the "generator" side of a hydraulic system that initiates the hydraulic procedure (as opposed to the "actuator" side that completes the hydraulic procedure). Regardless of disparities, all hydraulic pumps are responsible for displacing liquid volume and transporting it to the actuator(s) from the reservoir via the tubing system. Some form of internal combustion system typically powers pumps.

While the operation of hydraulic pumps is normally the same, these mechanisms can be split into basic categories. There are two types of hydraulic pumps to consider: gear pumps and piston pumps. Radial and axial piston pumps are types of piston pumps. Axial pumps produce linear motion, whereas radial pumps can produce rotary motion. The gear pump category is further subdivided into external gear pumps and internal gear pumps.

Each type of hydraulic pump, regardless of piston or gear, is either double-action or single-action. Single-action pumps can only pull, push, or lift in one direction, while double-action pumps can pull, push, or lift in multiple directions.

Vane pumps are positive displacement pumps that maintain a constant flow rate under varying pressures. It is a pump that self-primes. It is referred to as a "vane pump" because the effect of the vane pressurizes the liquid.

This pump has a variable number of vanes mounted onto a rotor that rotates within the cavity. These vanes may be variable in length and tensioned to maintain contact with the wall while the pump draws power. The pump also features a pressure relief valve, which prevents pressure rise inside the pump from damaging it.

Internal gear pumps and external gear pumps are the two main types of hydraulic gear pumps. Pumps with external gears have two spur gears, the spurs of which are all externally arranged. Internal gear pumps also feature two spur gears, and the spurs of both gears are internally arranged, with one gear spinning around inside the other.

Both types of gear pumps deliver a consistent amount of liquid with each spinning of the gears. Hydraulic gear pumps are popular due to their versatility, effectiveness, and fairly simple design. Furthermore, because they are obtainable in a variety of configurations, they can be used in a wide range of consumer, industrial, and commercial product contexts.

Hydraulic ram pumps are cyclic machines that use water power, also referred to as hydropower, to transport water to a higher level than its original source. This hydraulic pump type is powered solely by the momentum of moving or falling water.

Ram pumps are a common type of hydraulic pump, especially among other types of hydraulic water pumps. Hydraulic ram pumps are utilized to move the water in the waste management, agricultural, sewage, plumbing, manufacturing, and engineering industries, though only about ten percent of the water utilized to run the pump gets to the planned end point.

Despite this disadvantage, using hydropower instead of an external energy source to power this kind of pump makes it a prominent choice in developing countries where the availability of the fuel and electricity required to energize motorized pumps is limited. The use of hydropower also reduces energy consumption for industrial factories and plants significantly. Having only two moving parts is another advantage of the hydraulic ram, making installation fairly simple in areas with free falling or flowing water. The water amount and the rate at which it falls have an important effect on the pump"s success. It is critical to keep this in mind when choosing a location for a pump and a water source. Length, size, diameter, minimum and maximum flow rates, and speed of operation are all important factors to consider.

Hydraulic water pumps are machines that move water from one location to another. Because water pumps are used in so many different applications, there are numerous hydraulic water pump variations.

Water pumps are useful in a variety of situations. Hydraulic pumps can be used to direct water where it is needed in industry, where water is often an ingredient in an industrial process or product. Water pumps are essential in supplying water to people in homes, particularly in rural residences that are not linked to a large sewage circuit. Water pumps are required in commercial settings to transport water to the upper floors of high rise buildings. Hydraulic water pumps in all of these situations could be powered by fuel, electricity, or even by hand, as is the situation with hydraulic hand pumps.

Water pumps in developed economies are typically automated and powered by electricity. Alternative pumping tools are frequently used in developing economies where dependable and cost effective sources of electricity and fuel are scarce. Hydraulic ram pumps, for example, can deliver water to remote locations without the use of electricity or fuel. These pumps rely solely on a moving stream of water’s force and a properly configured number of valves, tubes, and compression chambers.

Electric hydraulic pumps are hydraulic liquid transmission machines that use electricity to operate. They are frequently used to transfer hydraulic liquid from a reservoir to an actuator, like a hydraulic cylinder. These actuation mechanisms are an essential component of a wide range of hydraulic machinery.

There are several different types of hydraulic pumps, but the defining feature of each type is the use of pressurized fluids to accomplish a job. The natural characteristics of water, for example, are harnessed in the particular instance of hydraulic water pumps to transport water from one location to another. Hydraulic gear pumps and hydraulic piston pumps work in the same way to help actuate the motion of a piston in a mechanical system.

Despite the fact that there are numerous varieties of each of these pump mechanisms, all of them are powered by electricity. In such instances, an electric current flows through the motor, which turns impellers or other devices inside the pump system to create pressure differences; these differential pressure levels enable fluids to flow through the pump. Pump systems of this type can be utilized to direct hydraulic liquid to industrial machines such as commercial equipment like elevators or excavators.

Hydraulic hand pumps are fluid transmission machines that utilize the mechanical force generated by a manually operated actuator. A manually operated actuator could be a lever, a toggle, a handle, or any of a variety of other parts. Hydraulic hand pumps are utilized for hydraulic fluid distribution, water pumping, and various other applications.

Hydraulic hand pumps may be utilized for a variety of tasks, including hydraulic liquid direction to circuits in helicopters and other aircraft, instrument calibration, and piston actuation in hydraulic cylinders. Hydraulic hand pumps of this type use manual power to put hydraulic fluids under pressure. They can be utilized to test the pressure in a variety of devices such as hoses, pipes, valves, sprinklers, and heat exchangers systems. Hand pumps are extraordinarily simple to use.

Each hydraulic hand pump has a lever or other actuation handle linked to the pump that, when pulled and pushed, causes the hydraulic liquid in the pump"s system to be depressurized or pressurized. This action, in the instance of a hydraulic machine, provides power to the devices to which the pump is attached. The actuation of a water pump causes the liquid to be pulled from its source and transferred to another location. Hydraulic hand pumps will remain relevant as long as hydraulics are used in the commerce industry, owing to their simplicity and easy usage.

12V hydraulic pumps are hydraulic power devices that operate on 12 volts DC supplied by a battery or motor. These are specially designed processes that, like all hydraulic pumps, are applied in commercial, industrial, and consumer places to convert kinetic energy into beneficial mechanical energy through pressurized viscous liquids. This converted energy is put to use in a variety of industries.

Hydraulic pumps are commonly used to pull, push, and lift heavy loads in motorized and vehicle machines. Hydraulic water pumps may also be powered by 12V batteries and are used to move water out of or into the desired location. These electric hydraulic pumps are common since they run on small batteries, allowing for ease of portability. Such portability is sometimes required in waste removal systems and vehiclies. In addition to portable and compact models, options include variable amp hour productions, rechargeable battery pumps, and variable weights.

While non rechargeable alkaline 12V hydraulic pumps are used, rechargeable ones are much more common because they enable a continuous flow. More considerations include minimum discharge flow, maximum discharge pressure, discharge size, and inlet size. As 12V batteries are able to pump up to 150 feet from the ground, it is imperative to choose the right pump for a given use.

Air hydraulic pumps are hydraulic power devices that use compressed air to stimulate a pump mechanism, generating useful energy from a pressurized liquid. These devices are also known as pneumatic hydraulic pumps and are applied in a variety of industries to assist in the lifting of heavy loads and transportation of materials with minimal initial force.

Air pumps, like all hydraulic pumps, begin with the same components. The hydraulic liquids, which are typically oil or water-based composites, require the use of a reservoir. The fluid is moved from the storage tank to the hydraulic cylinder via hoses or tubes connected to this reservoir. The hydraulic cylinder houses a piston system and two valves. A hydraulic fluid intake valve allows hydraulic liquid to enter and then traps it by closing. The discharge valve is the point at which the high pressure fluid stream is released. Air hydraulic pumps have a linked air cylinder in addition to the hydraulic cylinder enclosing one end of the piston.

The protruding end of the piston is acted upon by a compressed air compressor or air in the cylinder. When the air cylinder is empty, a spring system in the hydraulic cylinder pushes the piston out. This makes a vacuum, which sucks fluid from the reservoir into the hydraulic cylinder. When the air compressor is under pressure, it engages the piston and pushes it deeper into the hydraulic cylinder and compresses the liquids. This pumping action is repeated until the hydraulic cylinder pressure is high enough to forcibly push fluid out through the discharge check valve. In some instances, this is connected to a nozzle and hoses, with the important part being the pressurized stream. Other uses apply the energy of this stream to pull, lift, and push heavy loads.

Hydraulic piston pumps transfer hydraulic liquids through a cylinder using plunger-like equipment to successfully raise the pressure for a machine, enabling it to pull, lift, and push heavy loads. This type of hydraulic pump is the power source for heavy-duty machines like excavators, backhoes, loaders, diggers, and cranes. Piston pumps are used in a variety of industries, including automotive, aeronautics, power generation, military, marine, and manufacturing, to mention a few.

Hydraulic piston pumps are common due to their capability to enhance energy usage productivity. A hydraulic hand pump energized by a hand or foot pedal can convert a force of 4.5 pounds into a load-moving force of 100 pounds. Electric hydraulic pumps can attain pressure reaching 4,000 PSI. Because capacities vary so much, the desired usage pump must be carefully considered. Several other factors must also be considered. Standard and custom configurations of operating speeds, task-specific power sources, pump weights, and maximum fluid flows are widely available. Measurements such as rod extension length, diameter, width, and height should also be considered, particularly when a hydraulic piston pump is to be installed in place of a current hydraulic piston pump.

Hydraulic clutch pumps are mechanisms that include a clutch assembly and a pump that enables the user to apply the necessary pressure to disengage or engage the clutch mechanism. Hydraulic clutches are crafted to either link two shafts and lock them together to rotate at the same speed or detach the shafts and allow them to rotate at different speeds as needed to decelerate or shift gears.

Hydraulic pumps change hydraulic energy to mechanical energy. Hydraulic pumps are particularly designed machines utilized in commercial, industrial, and residential areas to generate useful energy from different viscous liquids pressurization. Hydraulic pumps are exceptionally simple yet effective machines for moving fluids. "Hydraulic" is actually often misspelled as "Hydralic". Hydraulic pumps depend on the energy provided by hydraulic cylinders to power different machines and mechanisms.

There are several different types of hydraulic pumps, and all hydraulic pumps can be split into two primary categories. The first category includes hydraulic pumps that function without the assistance of auxiliary power sources such as electric motors and gas. These hydraulic pump types can use the kinetic energy of a fluid to transfer it from one location to another. These pumps are commonly called ram pumps. Hydraulic hand pumps are never regarded as ram pumps, despite the fact that their operating principles are similar.

The construction, excavation, automotive manufacturing, agriculture, manufacturing, and defense contracting industries are just a few examples of operations that apply hydraulics power in normal, daily procedures. Since hydraulics usage is so prevalent, hydraulic pumps are unsurprisingly used in a wide range of machines and industries. Pumps serve the same basic function in all contexts where hydraulic machinery is used: they transport hydraulic fluid from one location to another in order to generate hydraulic energy and pressure (together with the actuators).

Elevators, automotive brakes, automotive lifts, cranes, airplane flaps, shock absorbers, log splitters, motorboat steering systems, garage jacks and other products use hydraulic pumps. The most common application of hydraulic pumps in construction sites is in big hydraulic machines and different types of "off-highway" equipment such as excavators, dumpers, diggers, and so on. Hydraulic systems are used in other settings, such as offshore work areas and factories, to power heavy machinery, cut and bend material, move heavy equipment, and so on.

Fluid’s incompressible nature in hydraulic systems allows an operator to make and apply mechanical power in an effective and efficient way. Practically all force created in a hydraulic system is applied to the intended target.

Because of the relationship between area, pressure, and force (F = P x A), modifying the force of a hydraulic system is as simple as changing the size of its components.

Hydraulic systems can transfer energy on an equal level with many mechanical and electrical systems while being significantly simpler in general. A hydraulic system, for example, can easily generate linear motion. On the contrary, most electrical and mechanical power systems need an intermediate mechanical step to convert rotational motion to linear motion.

Hydraulic systems are typically smaller than their mechanical and electrical counterparts while producing equivalents amounts of power, providing the benefit of saving physical space.

Hydraulic systems can be used in a wide range of physical settings due to their basic design (a pump attached to actuators via some kind of piping system). Hydraulic systems could also be utilized in environments where electrical systems would be impractical (for example underwater).

By removing electrical safety hazards, using hydraulic systems instead of electrical power transmission improves relative safety (for example explosions, electric shock).

The amount of power that hydraulic pumps can generate is a significant, distinct advantage. In certain cases, a hydraulic pump could generate ten times the power of an electrical counterpart. Some hydraulic pumps (for example, piston pumps) cost more than the ordinary hydraulic component. These drawbacks, however, can be mitigated by the pump"s power and efficiency. Despite their relatively high cost, piston pumps are treasured for their strength and capability to transmit very viscous fluids.

Handling hydraulic liquids is messy, and repairing leaks in a hydraulic pump can be difficult. Hydraulic liquid that leaks in hot areas may catch fire. Hydraulic lines that burst may cause serious injuries. Hydraulic liquids are corrosive as well, though some are less so than others. Hydraulic systems need frequent and intense maintenance. Parts with a high factor of precision are frequently required in systems. If the power is very high and the pipeline cannot handle the power transferred by the liquid, the high pressure received by the liquid may also cause work accidents.

Even though hydraulic systems are less complex than electrical or mechanical systems, they are still complex systems that should be handled with caution. Avoiding physical contact with hydraulic systems is an essential safety precaution when engaging with them. Even when a hydraulic machine is not in use, active liquid pressure within the system can be a hazard.

Inadequate pumps can cause mechanical failure in the place of work that can have serious and costly consequences. Although pump failure has historically been unpredictable, new diagnostic technology continues to improve on detecting methods that previously relied solely on vibration signals. Measuring discharge pressures enables manufacturers to forecast pump wear more accurately. Discharge sensors are simple to integrate into existing systems, increasing the hydraulic pump"s safety and versatility.

Hydraulic pumps are devices in hydraulic systems that move hydraulic fluid from point to point, initiating hydraulic power production. They are an important device overall in the hydraulics field, a special kind of power transmission that controls the energy which moving fluids transmit while under pressure and change into mechanical energy. Hydraulic pumps are divided into two categories namely gear pumps and piston pumps. Radial and axial piston pumps are types of piston pumps. Axial pumps produce linear motion, whereas radial pumps can produce rotary motion. The construction, excavation, automotive manufacturing, agriculture, manufacturing, and defense contracting industries are just a few examples of operations that apply hydraulics power in normal, daily procedures.

Even the best-performing hydraulic pumps from top hydraulic gear pump suppliers need to be replaced eventually. Because work and environmental conditions are different on every work site, it can be difficult to place an exact timeframe on how long a pump will last. In order to stay on top of the condition and remaining lifespan of hydraulic pumps, and hydraulic systems overall, it’s important to consider two things: 1) remaining seal life 2) how fast a pump’s efficiency is deteriorating.

Efficiency is the easier of these two criteria to keep track of. If a pump’s performance has been steadily deteriorating or has suddenly declined, then it is probably reaching the end of its lifespan and will need to be replaced to sustain a reliable hydraulic system. The easiest way to judge the deterioration in a pump’s performance is to monitor and compare cycle times (i.e., the speed at which the machine operates).

However, sometimes it is necessary to take exact measurements of a pump’s performance efficiency, which can be quantified by three different categories: volumetric efficiency, mechanical/hydraulic efficiency, and overall efficiency:

• Volumetric flow: Determined by dividing the actual flow delivered by a pump at a given pressure by its theoretical flow. Actual flow is measured using a flow meter. To calculate theoretical flow, multiply the pump’s displacement per revolution by its driven speed. The result will give you the volumetric efficiency at a particular pressure so it will be necessary to take these readings over a range of pressures as the pump may be very efficient at low pressure but very inefficient at higher pressures.

• Mechanical/hydraulic efficiency: Determined by dividing theoretical torque required to drive the pump by the actual torque required to drive the pump. Theoretical torque is measured in Newton meters. Measuring actual drive torque requires a dynamometer.

Volumetric efficiency helps assess the pump’s condition in the field. If there is wear or damage increasing internal leakage, this measurement can help identify whether pump maintenance is required. In addition to mechanical performance, overall efficiency helps determine if hydraulic pump replacement is necessary. To help calculate the drive power the pump requires at a given flow and pressure, you need to know its overall efficiency. If the drive power required increases or decreases, the pump is probably operating less efficiently.

A hydraulic pump system must be properly maintained to ensure it remains reliable, but there are other factors that impact reliability. These include temperature; a hydraulic pump is most stable in cooler temperatures. Overheated hydraulic oil will lose its lubricity and become oxidized, causing increased wear on metal parts and potentially hydraulic pump overheating. The ambient temperature of the operating environment needs to be considered as well and regulated using equipment such as forced-air coolers or a liquid-to-liquid cooler.

Any hydraulic pump installation requires a clean environment. Particle contamination is a common cause of equipment failure; high-pressure flow can impact particles in a way they ordinarily wouldn’t react. Therefore, specialized filtration systems are required, such as kidney-loop filtration systems that circulate oil through a filter to maintain a particulate-free flow. Water contamination is another threat; water intrusion and even the slightest amount of moisture and humidity can affect hydraulic fluid and components. Desiccant breathers, absorbent filters, and vacuum dehydrators may be used in a plant to control moisture levels.

For more information on maintaining hydraulic pumps and motors, or to order hydraulic pumps, and other hydraulic component supplies, contact White House Products Ltd. today at +44 (0) 1475-742500.

Pumps tend to be one of the biggest energy consumers in industrial operations. Pump motors, specifically, require a lot of energy. For instance, a 2500 HP triplex pump used for frac jobs can consume almost 2000 kW of power, meaning a full day of fracking can cost several thousand dollars in energy costs alone!

So, naturally, operators should want to maximize energy efficiency to get the most for their money. Even a 1% improvement in efficiency can decrease annual pumping costs by tens of thousands of dollars. The payoff is worth the effort. And if you want to remotely control your pumps, you want to keep efficiency in mind.

In this post, we’ll point you in the right direction and discuss all things related to pump efficiency. We’ll conclude with several tips for how you can maintain pumping efficiency and keep your energy costs down as much as possible.

In simple terms, pump efficiency refers to the ratio of power out to power in. It’s the mechanical power input at the pump shaft, measured in horsepower (HP), compared to the hydraulic power of the liquid output, also measured in HP. For instance, if a pump requires 1000 HP to operate and produces 800 HP of hydraulic power, it would have an efficiency of 80%.

Remember: pumps have to be driven by something, i.e., an electric or diesel motor. True pump system efficiency needs to factor in the efficiency of both the motor AND the pump.

Consequently, we need to think about how electrical power (when using electric motors) or heat power (when using combustion engines) converts into liquid power to really understand pump efficiency.

Good pump efficiency depends, of course, on pump type and size. High-quality pumps that are well-maintained can achieve efficiencies of 90% or higher, while smaller pumps tend to be less efficient. In general, if you take good care of your pumps, you should be able to achieve 70-90% pump efficiency.

Motor efficiency is also an important factor here. Motor efficiency depends on the fuel type, whether electricity or hydrocarbon, which in turn depends on availability and cost.

AC motors can achieve 90%+ efficiency when converting electrical to mechanical energy. Combustion engines are much less efficient, with typical efficiency ratings coming in at ~20% for gasoline and ~40% for diesel. Your choice of engine or motor type will depend on the availability and cost of fuel or electricity in your area.

Now that we have a better understanding of the pump efficiency metric, let’s talk about how to calculate it. The mechanical power of the pump, or the input power, is a property of the pump itself and will be documented during the pump setup. The output power, or hydraulic power, is calculated as the liquid flow rate multiplied by the "total head" of the system.

Remember: we’re trying to find the ratio of power in to power out. Since rations require equal units on both sides, we"ll have to do some conversions to get our hydraulic power units in HP. You"ll see how this is done in the example below.

IMPORTANT: to calculate true head, you also need to factor in the work the pump does to move fluid from the source. For example, if the source water is below the pump, you need to account for the extra work the pump puts in to draw source water upwards.

*Note - this calculation assumes the pump inlet is not pressurized and that friction losses are minimal. If the pump experiences a non-zero suction pressure, or if there is significant friction caused by the distance or material of the pipe, these should be factored in as well.

You"ll notice that the elevation head is minimal compared to the discharge pressure, and has minimal effect on the efficiency of the pump. As the elevation change increases or the discharge pressure decreases, however, elevation change will have a greater impact on total head.

Obviously, that’s a fair amount of math to get at the pump efficiency, considering all of the units conversions that need to be done. To avoid doing these calculations manually, feel free to use our simple pump efficiency calculator.

Our calculations use static variables (pump-rated horsepower and water source elevation) and dynamic variables (discharge flow and pressure). To determine pump efficiency, we need to measure the static variables only once, unless they change.

If you want to measure the true efficiency of your pump, taking energy consumption into account, you could add an electrical meter. Your meter should consist of a current transducer and voltage monitor (if using DC) for electrical motors or a fuel gauge for combustion. This would give you a true understanding of how pump efficiency affects energy consumption, and ultimately your bank account.

Up until this point, we’ve covered the ins and outs of how to determine pump efficiency. We’r