mud pump performance charts free sample

*Liberty Process Equipment, Inc. is not affiliated with nor distributor for Seepex®, Allweiler®, Moyno®, Tarby®, Netzsch®, or Continental Inc.® All referenced product names, brands, models, or part numbers is solely for identification purposes. Seepex® is a registered trademark of Seepex®. Moyno® and Tarby® are registered trademarks of Robins and Myers® and NOV®, Netzsch® Incorporated is a registered trademark of the Netzsch® Group, Allweiler® is a registered trademark of Colfax® Corporations Continental® Pumps is a Trademark of Continental® Ultra Pumps.

Pumps are often installed in Parallel in systems which exhibit considerable variations in flow or when the system has variable flow requirements and when these requirements can be achieved by switching the parallel pumps on and off. Typically, pumps installed in parallel are of a similar type and size. The pumps however can be of a different size or the pumps can be speed-controlled which of course means the pump performance curves will be different.

Figure 1 provides an illustration of a system with two identical pumps installed in parallel. The image shows how non-return valves are installed in series and downstream of each pump. This is to prevent bypass circulation when a pump is not running.

The total system performance curve for parallel pumps can be determined by adding Q1 and Q2 for every value of head which is the same for both pumps, i.e. H1 = H2. As the pumps, in this case, are identical, the resultant composite pump curve has the same maximum head value, Hmax but the maximum flow Qmax is twice as large. So, for each value of the head, the flow is double that of a single pump in operation.

Pumps are sometimes installed in parallel in pressure booster systems for water supply and for water supply in large buildings. Operational advantages can be achieved by connecting two or more pumps in parallel instead of installing just one single large pump. The total pump output is usually only required for a limited period. If a single pump was used in this instance, it would operate at a comparatively lower efficiency.

When a number of smaller pumps are installed in parallel, the system can be controlled to optimise or minimize the number of pumps operating and the pumps which are on will operate at or close-to the BEP (best efficiency point). To operate at the most optimal point, one of the pumps installed in parallel must have variable speed control.

Many pumping applications require fluids to be transported over long distances and against high static heads or total heads which are well in excess of the head that can be developed by a single pump. Examples of such scenarios would be, pumping tailings, power station ash, underground fill and pumping concentrates. Centrifugal pumps are occasionally installed in series to increase the operating range and standby capacity of the plant. Multi-stage pumps can be considered as a series type installation of single-stage pumps. However, single stages in multi-stage pumps cannot be decoupled.

If one of the pumps in a series type installation is not operational, it causes considerable resistance to the system. In an effort to overcome this, a bypass with non-return valve could be installed as shown in Figure 3.

The head associated with a given flow rate for pumps installed in series is can be determined by adding the single heads vertically as shown in Figure 4.

Pump installed in parallel are typically identical pumps. There may however, be applications or scenarios where dissimilar pumps are installed. Figure 6 shows an example system which has a total of four pumps, three of which are operating.

Pump 10 and 11 are dissimilar pumps (two different sized pumps) installed in the system. The composite curve for any combination of pumps can be plotted in FluidFlow. Figure 7 shows the composite curve for pumps 10 and 11.

The 2,200-hp mud pump for offshore applications is a single-acting reciprocating triplex mud pump designed for high fluid flow rates, even at low operating speeds, and with a long stroke design. These features reduce the number of load reversals in critical components and increase the life of fluid end parts.

The pump’s critical components are strategically placed to make maintenance and inspection far easier and safer. The two-piece, quick-release piston rod lets you remove the piston without disturbing the liner, minimizing downtime when you’re replacing fluid parts.

A comprehensive range of mud pumping, mixing, and processing equipment is designed to streamline many essential but time-consuming operational and maintenance procedures, improve operator safety and productivity, and reduce costly system downtime.

Created specifically for drilling equipment inspectors and others in the oil and gas industry, the Oil Rig Mud Pump Inspection app allows you to easily document the status and safety of your oil rigs using just a mobile device. Quickly resolve any damage or needed maintenance with photos and GPS locations and sync to the cloud for easy access. The app is completely customizable to fit your inspection needs and works even without an internet signal.Try Template

When two (or more) pumps are arranged in serial their resulting pump performance curve is obtained by adding theirheads at the same flow rate as indicated in the figure below.

Centrifugal pumps in series are used to overcome larger system head loss than one pump can handle alone. for two identical pumps in series the head will be twice the head of a single pump at the same flow rate - as indicated with point 2.

With a constant flowrate the combined head moves from 1 to 2 - BUTin practice the combined head and flow rate moves along the system curve to point 3. point 3 is where the system operates with both pumps running

When two or more pumps are arranged in parallel their resulting performance curve is obtained by adding the pumps flow rates at the same head as indicated in the figure below.

Centrifugal pumps in parallel are used to overcome larger volume flows than one pump can handle alone. for two identical pumps in parallel and the head kept constant - the flow rate doubles compared to a single pump as indicated with point 2

Note! In practice the combined head and volume flow moves along the system curve as indicated from 1 to 3. point 3 is where the system operates with both pumps running

In practice, if one of the pumps in parallel or series stops, the operation point moves along the system resistance curve from point 3 to point 1 - the head and flow rate are decreased.

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.

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.

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’re now ready for the exciting stuff - how to improve pump efficiency!

One of the easiest ways to improve pump efficiency is to actually monitor pumps for signs of efficiency loss! If you monitor flow rate and discharge (output power) along with motor current or fuel consumption, you’ll notice efficiency losses as soon as they occur. Simply having pump efficiency information on hand empowers you to take action.

Another way to increase efficiency is to keep pumps well-maintained. Efficiency losses mostly come from mechanical defects in pumps, e.g., friction, leakages, and component failures. You can mitigate these issues through regular maintenance that keeps parts in working order and reveals impending failures. Of course, if you are continuously monitoring your pumps for efficiency drops, you’ll know exactly when maintenance is due.

You can also improve pump efficiency by keeping pumps lubricated at all times. Lubrication is the enemy of friction, which is the enemy of efficiency (“the enemy of my enemy is my friend…”).

A fourth way to enhance pump efficiency is to ensure your pumps and piping are sized properly for your infrastructure. Although we’re bringing this up last, it’s really the first step in any pumping operation. If your pumps and piping don’t match, no amount of lubricant or maintenance will help.

In this post, we’ve given you the full rundown when it comes to calculating and improving pump efficiency. You can now calculate, measure, and improve pump efficiency, potentially saving your business thousands of dollars annually on energy costs.

For those just getting started with pump optimization, we offer purpose-built, prepackaged solutions that will have you monitoring pump efficiency in minutes, even in hazardous environments.

The motor used to power a centrifugal pump needs to be able to produce enough torque to start the pump and bring it to an optimal operating speed. If a motor lacks enough torque to operate a pump, the pump may not start or may only operate at a reduced speed. The centrifugal pump suppliers at PumpWorks will guide you through the pump motor selection process.

A pump’s torque-speed curve is used to determine the appropriate motor to match with it. A pump’s torque-speed curve is produced by plotting the percentage of full load torque (FLT) vertically against the percentage of full load speed (FLS) plotted horizontally. An example is shown below.

The torque-speed curve is similar for all centrifugal pumps due to simple math: the pump torque varies as the square of its speed. However, when the pump is at rest—0% full load speed—the full load torque is never also 0%. Starting a rotating pump requires the motor to overcome the pump inertia and static friction.

To overcome pump inertia and static friction, approximately 20% of full load torque is required. As the pump’s speed increases, the required torque gradually declines. For example, at about 15% full load speed the required torque typically is around 5% or 10% full load torque. As shown below, the pump torque-speed curve follows the square law:

Like pumps, motors produce a torque-speed curve of their own. By overlaying the torque-speed curve of a pump and a motor, one can verify that the motor is producing enough accelerating torque to drive the pump to full speed, as shown below.

In this overlay the shaded area reflects the accelerating torque available from the motor to drive the pump. Where the two curves intersect is the point at which the motor’s torque is insufficient to drive the pump any faster. In other words, this is the point of maximum pump speed while powered by this motor.

Torque at zero flow is especially important for pumps with axial flow (or propeller) designs. The torque-speed curve of such pumps is such that the highest HP, and therefore the highest torque, is required at zero flow. An axial-flow pump must be paired with a motor with adequate HP to get the pump moving.

Another important factor in motor selection is the pump’s inertia value at the motor shaft. Inertia is a measure of an object’s resistance to movement change. The higher the pump inertia, the longer the motor will take to start the pump and bring it to full load speed.

This is significant because motors draw current to bring pumps up to speed. The longer a motor takes to overcome a pump’s inertia, the more heat it will generate. A motor must be sized to handle the pump’s inertia to avoid damaging the motor’s windings.

If a motor directly drives the pump, the values of the pump and pump-motor coupling inertias are the same regardless of pump speed.  If the pump is driven by a gearbox and motor, however, the gearbox can have a major impact on inertia values. In this application inertia can be expressed as:

A gearbox’s effect on inertia can be understood by analogy to a bicycle. When a bicycle is ridden at high speeds, the rider may change to a higher gear ratio (one greater than 1.0) to go faster. Such a ratio also requires the rider to put in more effort. Likewise, if a gearbox shifts to a higher gear ratio, the motor will have a higher load. The same logic applies if the gearbox is reducing the motor speed to drive the pump slower. When the gearbox ratio is less than 1.0, it will reduce the load requirements on the motor.

Selecting the right pump and motor for a specific application can be a complex job. The team at PumpWorks is dedicated to finding pump solutions that meet the exact needs of each customer.

In this 101 blog, we’ll show you how to read a positive displacement (PD) pump curve so you can base your pump selection on the specific needs of your application. A PD pump produces the same flow at a given speed (in revolutions per minute--RPM) no matter what the discharge pressure. Positive displacement pump curves give you the information you need to determine a pump"s ability to produce flow under the conditions that affect pump performance.

As RPM increases, the pump flow increases, from 0 gallons per minute or (GPM) at 0 RPM, to about 130 GPM at 500 RPM.Fig. 1. A PD pump curve indicates pump capacity, on the horizontal lines, in units per minute. In this example, the curve indicates gallons per minute (GPM)andliters per minute (LPM)in the left margin and the vertical lines indicates pump speed in revolutions per minute (RPM).

Positive displacement pumps deliver a constant flow of fluid at a given pump speed. When viscosity increases, however, resistance to flow increases, so to maintain system flow at higher viscosities, pumps require more horsepower.

Low viscosity also affects pump performance in the form of slip. Slip is the internal recirculation of low viscosity fluid from the discharge side of the pump back to the suction side of the pump.The amount of slip in a PD pump is influenced by the fluid’s viscosity and the discharge pressure.As discharge pressure increases, keeping viscosity constant, more fluid slips from the discharge side to the suction side of the pump, so the pump must spin at a higher RPM to maintain output.

In Fig. 2, a positive displacement pump curve shows the influence of viscosity on slip with a correction chart. With changes in viscosity and pressure, slip correction indicates that flow capacity drops from a high of about 7 GPM to a low of about 3.5 GPM. Once viscosity is over 1000 cPs, slip basically doesn’t occur in liquid sanitary pumps. If slip is not a factor, use the 0 PSI line to determine flow rate.

Because PD pumps generate flow to transport relatively high viscosity fluids, PD pump selection requires analysis of three key influences on fluid transfer:

The fluid’s dynamic viscosity, density, and response to shear.Fig. 2.Slip correction accounts for variations in pump performance while factoring fluid viscosity (resistance to flow) and discharge pressure.

Dynamic viscosity is a measure of a fluid’s resistance to flow. By common sense alone, we can imagine that water is less viscous, or resistant to flow, than corn syrup, so corn syrup has a higher viscosity than water. We measure internal resistance to flow as absolute viscosity (also referred to as dynamic viscosity). It is critical for the viscosity used to be consistent with “in pump” shear conditions, or shear rates of 800 or more s-1 (inverse seconds).As the following comparison shows, differences in viscosity vary dramatically by fluid:

Shear-sensitive liquids change viscosity when under stress,such as when they are hit by an impeller inside a pump. Some liquids become less viscous with increased force (called shear thinning), while others become more viscous with increased force (called shear thickening).

Continuing with the ketchup processing example, the next section discusses additional important information on pump curves: work horsepower (WHP), viscous horsepower (VHP), and Net Positive Suction Head required (NPSHr).

When you size a PD pump it will be important to select the correct brake horsepower. Brake horsepower (BHP) is the power the pump requires to overcome the discharge pressure. BHP is determined by adding the work horsepower (WHP) and the viscous (VHP) horsepower.

Work horsepower (WHP) is the horsepower required for the selected PD pump to achieve the desired flow rate considering the anticipated pressure drop from system components. Components like valves, heat exchangers, and filter/strainers, to name a few. WHP is sometimes called external horsepower.

To determine WHP find the intersection of anticipated differential pressure (PSI) and RPM, as shown in Fig. 3. Recall the required RPM was a result of flow required coupled with slip correction, if any.Fig. 3. Work horsepower (WHP), is the horsepower required to operate a Positive Displacement Pump. As pressure from the discharge side of the pump increases, the pump requires additional horsepower to operate. For example, at 300 RPM and with 150 PSI, the pump requires 6.7 working horsepower.

Maintaining pump capacity at various viscosities requires meeting horsepower minimums, as shown in Fig. 4. There is a certain minimum horsepower requirement to force the rotating parts of the pump to turn, considering the viscosity of the fluid in the pump. VHP is sometimes called internal horsepower.

Required HP is 6.7 + 4 = 10.7Fig. 4. Viscous Horsepower (VHP) is the power needed to turn rotating parts of the pump against the fluid inside the pump. At 300 RPM and a viscosity of 500 CPS, a pump requires 4 VHP.

Finally, curves show NPSHr, which stands for Net Positive Suction Head Required. NPSHr is the minimum amount of pressure required on the suction side of the pump to avoid cavitation.Cavitation is the formation of vapor filled cavities, or bubble, which can rapidly expand and collapse causing damage to the pump and/or process piping. NPSHr is determined by the pump.

Net Positive Suction Head Available (NPSHa), is determined by the process piping. You always want NPSHa to be greater than NPSHr. AS Fig. 5. Illustrates, the lower the speed of a PD pump, the lower the NPSHr.

Fig. 5. Without enough net positive suction, the pump will cavitate, which affects performance and pump life. NPSHr varies as a function of speed (RPM).

Head is defined as the height to which a pump can raise water straight up.While raising water straight up may not always be useful, based on the layout of process piping, water creates resistance at predictable rates, so we can calculate head as the differential pressure that a pump has to overcome in order to displace the water. Common units are feet of head and pounds per square inch. As Figure 6 illustrates, every 2.31 feet of head equals 1 PSI of pressure.The formula for PSI: Feet of head / 2.31 = PSI

Total Dynamic Head (TDH) is the amount of head or PSI of pressure on the suction side of the pump (also called static lift), plus the total of 1) height that a fluid is to be pumped plus 2) friction loss caused by internal pipe roughness or corrosion.

As you processor, you need a pump that transfers product safely and efficiently from point A to point B. But with such a large variety of pumps, motors, and applications, picking the right pump can be difficult.That"s where we come in!

CSI is known as the experts in the specification, sizing, and supplying of pumping technology for hygienic industry processes. Speak with our knowledgeable pump team today and be confident in your next pump purchase!

Central States Industrial Equipment (CSI) is a leader in distribution of hygienic pipe, valves, fittings, pumps, heat exchangers, and MRO supplies for hygienic industrial processors, with four distribution facilities across the U.S. CSI also provides detail design and execution for hygienic process systems in the food, dairy, beverage, pharmaceutical, biotechnology, and personal care industries. Specializing in process piping, system start-ups, and cleaning systems, CSI leverages technology, intellectual property, and industry expertise to deliver solutions to processing problems. More information can be found at www.csidesigns.com.

This guide is intended for engineers, production managers, or anyone concerned with proper pump selection for pharmaceutical, biotechnology, and other ultra-clean applications.

How to read a pump performance curve remains a topic of great interest across the food, dairy, beverage, and pharmaceutical processing industries, so in this post we provide important information on two of our most popular styles —

With manufacturing lead times growing, selecting the right pump the first time is more important than ever. At the same time, understanding the full range of each pump’s capabilities under specific operating conditions gives you a window to your options, so you’re not locked in to just a few choices during the selection process.

Also called a pump selection curve, pump efficiency curve, or pump performance curve, a pump curve chart gives you the information you need to determine a pump"s ability to produce flow under the conditions that affect pump performance. Reading pump curves accurately helps you choose the right pump based on application variables such as:

A pump has to produce enough pressure differential to overcome head loss created in pipe systems by friction, valves, and fittings. A pump curve shows the two performance factors on the X,Y axis so you can see the volume of fluids a pump can transfer under various pressure conditions.

For example, if you know the flow rate your application requires, you find the gallons per minute (or hour) rate along the bottom horizontal line of the curve and then draw a line up to the head/PSI you require. The curve will show you if the pump you have selected will perform in that application.

Centrifugal pump curves are useful because they show pump performance metrics based on head (pressure) produced by the pump and water-flow through the pump. Flow rates depend on pump speed, impeller diameter, and head.

Head is the height to which a pump can raise water straight up.Water creates pressure or resistance, at predictable rates, so we can calculate head as the differential pressure that a pump has to overcome in order to raise the water.

Common units are feet of head and pounds per square inch. (A pump curve calculator might offer different units such as Bar or meters of head). As Figure 1 illustrates, every 2.31 feet of head equals 1 PSI.

Flow is the volume of water a pump can move at a given pressure. Flow is indicated on the horizontal axis in units like gallons per minute, or gallons per hour, as shown in Figure 2.

Total Dynamic Head (TDH) is the amount of head or pressure on the suction side of the pump (also called static lift), plus the total of 1) height that a fluid is to be pumped plus 2) friction loss caused by internal pipe roughness or corrosion.

Let"s say you want to know the flow rate you can achieve from the pump in Figure 3 at 60 Hz when the design pressure is 80 PSI. In this case, the curve shows that the pump can achieve a flow rate of 1321 gallons per hour at 80 PSI of discharge pressure.

Because some centrifugal pumps operate across a range of horsepower, their curves will include additional information. Figure 4, for example, features a pump that can operate from 2 to 10 horsepower depending on desired performance.

Impeller size is another variable for meeting performance requirements. The curve above shows impeller trim sizes, at the right end of each curve, ranging from a minimum of 4.33" to a maximum of 6.42".

Reducing impeller size enables you to limit the pump to specific performance requirements. The curve above shows maximum pump performance with a full-trim impeller, minimum pump performance with a minimum-trim impeller, and performance delivered by the design-trim impeller, or the impeller trim closest to the design condition. Impellers are typically trimmed 0.20 inches (or 5mm) at a time.

In addition to pressure and flow, the curve at the bottom of Figure 4 indicates NPSHr, which stands for Net Positive Suction Head Required.NPSHr is the minimum amount of pressure required on the suction side of the pump to avoid cavitation, or the introduction of air into the fluid stream. NPSHr is determined by the pump. You always want NPSHa>NPSHr.

Good pump efficiency means that a pump is not wasting energy in order to maintain its performance point. No pump is 100% efficient, however, in the work it has to do to transfer liquids.

When selecting a pump and motor combination, consider not only the total current demand but future demand to ensure your selection has the capacity to meet changing requirements. To that end, sizing the pump for performance variables rather than peak efficiency is a common practice.

For example, while the middle of the pump efficiency curve is generally where a pump is operating at maximum efficiency in terms of pressure and flow rate, moving right on the curve above shows an increase in horsepower needed to maintain a flow rate as head increases. For example, 2 hp is required for a flow rate of 40 gpm with 80 feet of head, but maintaining 40 gpm of flow at 110 feet of head would require a 3 hp motor.

You can audit pumping systems using pump performance characteristics. Once you determine the best efficiency point (BEP) for your application, you can make adjustments to improve overall system efficiency, such as adding a variable frequency drive (VFD) and changing the diameter of the pump impeller. Controlling flow rate by adjusting pump speed via VFD instead of pressure valves can result in better efficiency and greater energy savings.

When using pumps in parallel, you can increase flow rate at the same rate of head.As figure 5 illustrates, using pumps in parallel gives you a flow rate that is the sum of pump A and pump B’s flow rates.

A positive displacement (PD) pump produces the same flow at a given speed (in revolutions per minute--RPM) no matter what the discharge pressure. Positive displacement pump curves give you the information you need to determine a pump"s ability to produce flow under the conditions that affect pump performance.

As RPM increases, the pump flow increases, from 0 gallons per minute or (GPM) at 0 RPM, to about 130 GPM at 500 RPM. Remember that some performance curve calculators might include units such as liters per minute (LPM), so check calculation units when using calculators.

Fig. 7. A PD pump curve indicates pump capacity, on the horizontal lines, in units per minute. In this example, the curve indicates gallons per minute (GPM)andliters per minute (LPM)in the left margin and the vertical lines indicates pump speed in revolutions per minute (RPM).

Positive displacement pumps deliver a constant flow of fluid at a given pump speed. When viscosity increases, however, resistance to flow increases, so to maintain system flow at higher viscosities, pumps require more horsepower.

Low viscosity also affects pump performance in the form of slip. Slip is the internal recirculation of low viscosity fluid from the discharge side of the pump back to the suction side of the pump.The amount of slip in a PD pump is influenced by the fluid’s viscosity and the discharge pressure.

As discharge pressure increases, keeping viscosity constant, more fluid slips from the discharge side to the suction side of the pump, so the pump must spin at a higher RPM to maintain output.

In Fig. 8, a positive displacement pump curve shows the influence of viscosity on slip with a correction chart. With changes in viscosity and pressure, slip correction indicates that flow capacity drops from a high of about 7 GPM to a low of about 3.5 GPM. Once viscosity is over 1000 cPs, slip basically doesn’t occur in liquid sanitary pumps. If slip is not a factor, use the 0 PSI line to determine flow rate.

Because PD pumps generate flow to transport relatively high viscosity fluids, PD pump selection requires analysis of three key influences on fluid transfer:

Dynamic viscosity is a measure of a fluid’s resistance to flow. By common sense alone, we can imagine that water is less viscous, or resistant to flow, than corn syrup, so corn syrup has a higher viscosity than water. We measure internal resistance to flow as absolute viscosity (also referred to as dynamic viscosity). It is critical for the viscosity used to be consistent with “in pump” shear conditions, or shear rates of 800 or more s-1 (inverse seconds). As the following comparison shows, differences in viscosity vary dramatically by fluid:

Shear-sensitive liquids change viscosity when under stress,such as when they are hit by an impeller inside a pump. Some liquids become less viscous with increased force (called shear thinning), while others become more viscous with increased force (called shear thickening).

Continuing with the ketchup processing example, the next section discusses additional important information on pump curves: work horsepower (WHP), viscous horsepower (VHP), and Net Positive Suction Head required (NPSHr).

When you size a PD pump it will be important to select the correct brake horsepower. Brake horsepower (BHP) is the power the pump requires to overcome the discharge pressure. BHP is determined by adding the work horsepower (WHP) and the viscous (VHP) horsepower.

Work horsepower (WHP) is the horsepower required for the selected PD pump to achieve the desired flow rate considering the anticipated pressure drop from system components. Components like valves, heat exchangers, and filter/strainers, to name a few. WHP is sometimes called external horsepower.

Fig. 9. Work horsepower (WHP), is the horsepower required to operate a Positive Displacement Pump. As pressure from the discharge side of the pump increases, the pump requires additional horsepower to operate. For example, at 300 RPM and with 150 PSI, the pump requires 6.7 working horsepower.

Maintaining pump capacity at various viscosities requires meeting horsepower minimums, as shown in Fig. 10. There is a certain minimum horsepower requirement to force the rotating parts of the pump to turn, considering the viscosity of the fluid in the pump. VHP is sometimes called internal horsepower.

Fig. 10. Viscous Horsepower (VHP) is the power needed to turn rotating parts of the pump against the fluid inside the pump. At 300 RPM and a viscosity of 500 CPS, a pump requires 4 VHP.

As you processor, you need a pump that transfers product safely and efficiently from point A to point B. But with such a large variety of pumps, motors, and applications, picking the right pump can be difficult.That"s where we come in!

CSI is known as the experts in the specification, sizing, and supplying of pumping technology for hygienic industry processes. Speak with our knowledgeable pump team today and be confident in your next pump purchase!

Central States Industrial Equipment (CSI) is a leader in distribution of hygienic pipe, valves, fittings, pumps, heat exchangers, and MRO supplies for hygienic industrial processors, with four distribution facilities across the U.S. CSI also provides detail design and execution for hygienic process systems in the food, dairy, beverage, pharmaceutical, biotechnology, and personal care industries. Specializing in process piping, system start-ups, and cleaning systems, CSI leverages technology, intellectual property, and industry expertise to deliver solutions to processing problems. More information can be found at www.csidesigns.com.

This guide is intended for engineers, production managers, or anyone concerned with proper pump selection for pharmaceutical, biotechnology, and other ultra-clean applications.

Cavitation is an undesirable condition that reduces pump efficiency and leads to excessive wear and damage to pump components. Factors that can contribute to cavitation, such as fluid velocity and pressure, can sometimes be attributed to an inadequate mud system design and/or the diminishing performance of the mud pump’s feed system.

When a mud pump has entered full cavitation, rig crews and field service technicians will see the equipment shaking and hear the pump “knocking,” which typically sounds like marbles and stones being thrown around inside the equipment. However, the process of cavitation starts long before audible signs reveal themselves – hence the name “the silent killer.”

Mild cavitation begins to occur when the mud pump is starved for fluid. While the pump itself may not be making noise, damage is still being done to the internal components of the fluid end. In the early stages, cavitation can damage a pump’s module, piston and valve assembly.

The imperceptible but intense shock waves generated by cavitation travel directly from the fluid end to the pump’s power end, causing premature vibrational damage to the crosshead slides. The vibrations are then passed onto the shaft, bull gear and into the main bearings.

If not corrected, the vibrations caused by cavitation will work their way directly to critical power end components, which will result in the premature failure of the mud pump. A busted mud pump means expensive downtime and repair costs.

To stop cavitation before it starts, install and tune high-speed pressure sensors on the mud suction line set to sound an alarm if the pressure falls below 30 psi.

Accelerometers can also be used to detect slight changes in module performance and can be an effective early warning system for cavitation prevention.

Although the pump may not be knocking loudly when cavitation first presents, regular inspections by a properly trained field technician may be able to detect moderate vibrations and slight knocking sounds.

Gardner Denver offers Pump University, a mobile classroom that travels to facilities and/or drilling rigs and trains rig crews on best practices for pumping equipment maintenance.

Severe cavitation will drastically decrease module life and will eventually lead to catastrophic pump failure. Along with downtime and repair costs, the failure of the drilling pump can also cause damage to the suction and discharge piping.

When a mud pump has entered full cavitation, rig crews and field service technicians will see the equipment shaking and hear the pump ‘knocking’… However, the process of cavitation starts long before audible signs reveal themselves – hence the name ‘the silent killer.’In 2017, a leading North American drilling contractor was encountering chronic mud system issues on multiple rigs. The contractor engaged in more than 25 premature module washes in one year and suffered a major power-end failure.

Gardner Denver’s engineering team spent time on the contractor’s rigs, observing the pumps during operation and surveying the mud system’s design and configuration.

The engineering team discovered that the suction systems were undersized, feed lines were too small and there was no dampening on the suction side of the pump.

Following the implementation of these recommendations, the contractor saw significant performance improvements from the drilling pumps. Consumables life was extended significantly, and module washes were reduced by nearly 85%.

Although pump age does not affect its susceptibility to cavitation, the age of the rig can. An older rig’s mud systems may not be equipped for the way pumps are run today – at maximum horsepower.