Vertiflo Pump Company

Excerpt from the September 2022 Pumps & Systems Article by the Hydraulic Institute

One common mining industry pump is a centrifugal slurry pump.

What types of pumps are used in the mining industry?

When mining ore to extract useful minerals from the earth, pump systems are depended on to make sure that day-to-day operation runs efficiently. There are numerous types of pumps that are utilized in the mining industry.

One common type of pump is a centrifugal slurry pump, which is suitable for pumping liquid containing solids. Slurry is a mixture of solids (specific gravity typically greater than in a liquid carrier, usually water.

The following are slurry characteristics:

• Slurries are often used to transport solids.
• Properties of the solids and the liquid, as well as the number of solids, are variable.
• The solids particle size may vary from a few micrometers to hundreds of millimeters.
• Depending upon size, solids tend to settle below different threshold transport velocities.
• Slurry may behave like a Newtonian or non-Newtonian fluid.
• It may be abrasive and/or corrosive depending on the composition.

Slurry pumps (Image 1) are typically used to transport slurries with specific gravities up to 5.3 and solids concentration between 2% and 50% by volume.

Slurries with solids of wood, paper, specialized chemical particulates, wastewater and other organic materials also exist but are not the focus of this article.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.

Excerpt from the February 2022 Pumps & Systems Article by the Hydraulic Institute

How is vibration due to structural resonance avoided in vertical pumps?

Vertically suspended pump types VS1, VS2, VS3, VS6 and VS7 are typically flexible structures above the mounting plate. Focusing on the above-base structure of a vertical pump and the frequency of the first bending mode, it may coincide with running speed(s) or other forced vibration frequencies. If the pump is operated in a resonant condition (running speed coincident with a structural natural frequency), then amplification of the forced vibration can occur resulting in unacceptable levels. If the pump has a variable speed drive (VSD), the probability of a forced vibration frequency coinciding with a structural natural frequency increases greatly. To prevent the structural natural frequencies of the upper pump structure from being resonant, manufacturers usually conduct a structural dynamic analysis, as described in ANSI/HI 9.6.8 “Rotodynamic Pumps: Guideline for Dynamics of Pumping Machinery.”

Because there are usually two windows in the discharge head/driver support, the lateral stiffness in one direction may be different than the lateral stiffness in the other direction. This difference results in structural natural frequencies for each mode in-line with the discharge pipe different than the structural natural frequencies for each mode perpendicular to the discharge pipe (Image 3). If we consider the forced vibration due to unbalance, a minimum frequency separation margin is desired between the first structural natural frequencies of the upper structure and the operating speed for a fixed motor speed unit, or the range of operating speeds for VSD units.

Within this example the operating speed would need to be below 1,450 cycles per minute (cpm) or above 1,610 cpm. If the pump needs to operate in the “noncontinuous operating zone” identified in Image 3, the designer would need to evaluate how to increase or decrease the natural frequencies in each direction.

Changing the pump structural natural frequencies may require one or more design modifications to the structural elements—including changing the window or shell geometry of the driver support or discharge head, adding ribs or gussets, changing the structural height, modifying the flexibility of the flanged joints, or selecting a driver with a different stiffness, weight or center of gravity location or mounting arrangement.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.

Excerpt from the September 2022 Pumps & Systems Article by Pete Gaydon, the Hydraulic Institute

Workforce challenges mean more veterans are retiring while newcomers learn the basics.

Like most industrial and manufacturing industries, the pumping and fluid handling industry is facing workforce challenges. This includes a challenge to attract young professionals to the manufacturing, construction and municipal industries. These industries have experienced workforces that are moving toward retirement and taking years of industry knowledge with them.

This challenge requires the industry to communicate the importance of fluid handling to everyday life and how a career provides an opportunity to work in a secure industry—while impacting society by providing equipment and services that are integral to so much of what we enjoy.

This is no small task, and it is only the first step. Once new talent is attracted, companies have the daunting task of educating and training employees on their processes, products they manufacture or services they deliver. However, first, the fundamentals must be covered. This article takes a first crack at fundamental knowledge topics that cut across the fluid handling industry, while understanding there will be differing specifics and knowledge levels needed for varying positions. The end goal is to design and build reliable and efficient systems that meet their intended purpose. To achieve this goal, the manufacturers, system designers, construction contractors and owners must have a common and fundamental understanding of the topics listed within this article.

Pump Systems

Understanding the type of pump system and its needs is important because it defines the hydraulic needs and the design of the pumping equipment. Systems could be open to atmospheric pressure or not, be friction or static head dominated, have variable or constant demand, be clean or contain solids, and could be water based or have some other physical properties. Each of these fundamental considerations will be important to the pump system design, installation, control and selection of the pump(s).

Pump Types, Design & Application Fundamentals 

Pumps come in many shapes and sizes to meet all different system and fluid demands. It is important to understand the commonality and differences in the technologies.

The most fundamental division is rotodynamic versus positive displacement. Rotodynamic pumps have a rotating impeller/propeller/rotor that rotates in a casing/collector. Positive displacement pumps can be rotary type, which have meshing components (for example gears and screws) or reciprocating types, which have pistons, plungers or diaphragms that displace the liquid. The rotodynamic types increase the velocity of the liquid from the inlet to the outlet of the impeller, and positive displacement pumps trap and move a specific volume of liquid with every rotation of the pump shaft. This technology difference results in rotodynamic pumps operating at some maximum pressure that is related to the rotational velocity and positive displacement pumps operating at almost any pressure to deliver the liquid (Image 1).

This fundamental difference needs to be understood because it will affect the applications where each is best suited. Beyond this broad technology difference, there are countless variations in design, orientation and installation that are applied to meet specific market and application needs. A basic understanding of the design variations, benefits and limitations of the design variation, as well as general application considerations, are important for all.

>>Read more.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.

Excerpt from the June 2022 Pumps & Systems Article by Kyle Clark, the Hydraulic Institute

Think again if you are pumping thick fluids using water pump performance curves.

Viscosity is a fundamental property of a liquid. It is a fluid’s resistance to flow and is higher for thicker fluids. For example, a fluid with high viscosity, such as maple syrup, is thicker and resists flow more when compared to a fluid with a lower viscosity, like water.

Typically, pump manufacturers use water to obtain the values for their pump performance curves, even if the intended service of the pump is for a fluid with properties that are different from water. But what happens when the fluid’s viscosity significantly deviates from water? This is where engineers need to adjust the pump performance curves to account for the difference in viscosity between water and the actual fluid in the pump.

Pump performance curves describe the head added to a fluid, pump power and net positive suction head required (NPSHr) at a variety of different volumetric flow rates. Due to the importance of centrifugal pump performance in every fluid industry, it is imperative that accurate corrections are used when a centrifugal pump uses a thicker fluid than what the pump manufacturer used to evaluate the performance. A more viscous fluid will generally experience a decrease in volumetric flow rate, head and efficiency compared to water at the same pump speed. Likewise, pump power and NPSHr increase as viscosity increases.

Pump manufacturers that only provide water performance curves for pumps should consider providing performance curves for thicker fluids. Engineers who have been correcting the water performance curves when pumping thicker fluids should consider using the American National Standards Institute/Hydraulic Institute (ANSI/HI) 9.6.7-2015 guidelines.

While it is preferred to use actual performance curve data from pump manufacturers for thicker fluids, ANSI/HI 9.6.7-2015 provides a commonly used guideline to correct pump performance based on viscosity. This guideline has an acceptable amount of uncertainty, but it is imperative to understand the uncertainties of this method to ensure its correct application in pumping systems. This article summarizes technical findings and discussion as to why the guideline is acceptable despite the uncertainties.

Viscosity corrections rely on empirical methods using test data to properly account for a pump performance when the service fluid has a different viscosity than the reference fluid, typically water. As with many empirical methods, uncertainty inevitably exists and falls into one of the following categories:

1. The use of a dimensionless number to characterize complex phenomenon
2. The limited data set used to create the empirical model
3. The reliability of data measurement equipment

Before going into more detail, it is worth discussing why performance decreases when pumping a viscous fluid.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.

Excerpt from the April 2022 Pumps & Systems Article by the Hydraulic Institute

Face treatments increase the opening force by hydrostatic or hydrodynamic methods.

Pumps are at the heart of most industrial processes and the second most common machine in the world (after the electric motor). Because they are so common, pumps are often overlooked as a potential source of improved productivity or a cause of excess costs if not operated properly.

The most common seal face pattern is a plain flat surface designed to operate with minimal friction. However, various treatments can be done to seal faces to meet specific application needs. In general, seal face treatments are a means of modifying the pressure distribution between the seal faces. Images 1 and 2 show two more common face treatments that include spiral grooves and hydropads.

The most common objective of face treatments is to increase the opening force and thereby reduce the force of the mechanical contact. It can be useful when friction must be reduced to prevent vaporization of the fluid film or in applications involving a combination of high pressure and low viscosity of fluid.

Face treatments increase the opening force by hydrostatic or hydrodynamic methods. Hydrostatic forces do not depend on the rotational speed, whereas hydrodynamic forces vary with the rotational speed and viscosity of the fluid.

The simplest face treatment is a plain face that is angled. This design produces forces that are primarily hydrostatic. An example is a face subject to pressure at the outer diameter that is lapped so it touches the mating ring at the inside diameter. This means that the leakage path is converging. Care must be taken in determining the optimum angle, as too little taper will reduce the lubrication to the faces causing them to run hot. Too much taper will cause face separation with high leakage.

>>Read more.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.

Excerpt from the September 2021 Pumps & Systems Article by Asma Motlani

Learn the symptoms of cavitation and solutions to correct it.

Pumps are at the heart of most industrial processes and the second most common machine in the world (after the electric motor). Because they are so common, pumps are often overlooked as a potential source of improved productivity or a cause of excess costs if not operated properly.

As with any machine, some problems can occur. A common problem in pumping systems is pump cavitation. Pump cavitation causes a number of issues including excess noise, vibration and energy usage, not to mention serious damage to the pump itself.

What causes cavitation?

Imagine pinching a water hose and the water moves faster coming out but it is aerated and spread out. That is what happens with pump cavitation. It is a physical phenomenon that occurs when the pressure of the liquid incoming becomes lower than the vapor pressure of the liquid. A reduction in pressure is typically caused by increased speed of the fluid. When fluid pressure on the trailing side of the impeller blade (opposite the pump intake) falls below the vaporization point of the fluid, vapor bubbles begin to form. As the bubbles/cavities travel to the discharge side of the pump, moving to a high pressure area, the cavities implode. The imploding or collapsing of these bubbles trigger intense shockwaves inside the pump, causing damage to the impeller, vibration and excess noise.

These shock waves can cause mechanical damage to the impeller and pump, only increasing in severity over time and leading to potential pump failure. Factors that impact the degree of compression for the vapor bubbles are the speed and shape of the impeller.

When dealing with liquids of higher temperatures, the risk of this occurrence is increased due to increased vapor pressure.

What’s the difference between deadhead & cavitation?

Pump cavitation and dead head are similar concepts but far from the same.

When a pump operates with no flow through the pump due to a closed discharge valve or line blockage, a dead head has occurred. The pump recirculates the same water, causing water temperature to continually rise. If the pump continues to run in a dead-headed condition for too long, excessive heating can damage expensive seals and reduce the life of the pump.

Dead heading in a centrifugal pump can lead to explosions due to the energy being put into the liquid in the pump. Hydraulic overpressure and possible chemical reactions in the pump can also be caused by the overexertion of pressure. The same results can be caused by running the pump dry for an extended period, which can lead to cavitation.

Dead head means the outflow valve is open so the pump continues to circulate the same liquid over and over, which can damage the pump motor because the liquid can get too hot. The low power protection will work to detect this condition and trip to protect the motor.

Cavitation is similar in that the low power protection will detect it and trip and protect the motor as well. But this condition means that the pump is running dry and no liquid is there to pump. That too will cause the motor to overheat.

>>Read more.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.

Excerpt from the October 2021 Pumps & Systems Article by Pete Gaydon

This foundation is beneficial to understand while working with an entire system.

The term “total head” (H) is used to describe the energy in pumping systems and is how manufacturers represent the performance of their pumps as a function of flow rate. Total head is also commonly referred to as total dynamic head (TDH); however, the Hydraulic Institute (HI) uses the term total head and it will be used throughout this article.

It is important to understand the nuances of what makes up the total head of the system as a function of flow rate and varying system conditions so that if a user is designing or operating a pump system, the pump can be selected and operated properly. Additionally, if the goal is to measure the pump performance after installation, it is important to understand how to do that in the same way that the pump manufacturer will.

Total head (system) is made up of three components:

Elevation head, which is the difference in elevation that liquid will travel. For example, if a user was pumping from one tank to another and the level in the tanks were the same, there would be zero elevation head. But if pumping from a tank at ground level to the roof of a 100-foot building, there would be 100 feet of elevation head.

Pressure head is the difference in pressure between source and destination. For example, if taking liquid from a lake at atmospheric pressure and delivering it to a tank that had 10 pounds per square inch (psi) above atmospheric pressure, the pressure head would be 10 psi expressed as feet of the liquid being pumped. The conversion between pressure and head is described in the pump total head measurement section.

Friction head is the head loss in the system due to friction and is a function of the liquids velocity or flow rate squared. As mentioned, the friction loss will depend on the flow rate but also the size of the piping, fittings, valves and end use equipment in the system. If there are control valves in the system that are used to actively regulate the flow rate, the friction loss across the control valve is referred to as control head. It is important to understand control head because it is often a source of energy consumption that can be improved.

>>Read more.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.

Excerpt from the August 2021 Pumps & Systems Article by Peter Wolff

Understand how cavitation can damage your system.

Cavitation is a condition that can affect any fluid flow system. Despite it being an ever-present threat, it is not well understood. In the simplest possible terms, cavitation involves the formation of water vapor bubbles that damage metal components when they collapse back to the liquid phase. Here are some common questions and answers that relate to cavitation.

Does a pump sound differently when it cavitates?

Yes. Cavitation has been described as sounding like gravel or coffee beans in the system.

How does cavitation damage system components?

One aspect of cavitation that is not widely understood is why these apparently harmless bubbles are so destructive when they implode. The answer is in the release of latent heat energy of condensation when the water vapor returns to its liquid phase. The collapse of the bubble and the energy released creates a small pressure jet that can strike a nearby solid surface, potentially damaging it. Because of the large number of bubbles formed in a cavitating system, these bubbles of water vapor can cause extensive damage to system components over time. Because cavitation takes place on the entry to a pump, the first system component that the bubbles encounter is the pump impeller.

Where else can cavitation happen?

Virtually anywhere that water is moving fast. The most well-known locations, aside from pumps, are ships’ propellers, control valve seats and small-bore orifice plates in water pipework.

What causes cavitation in pumps?

Cavitation in pumps is caused by excessively low pressure at the pump inlet. A blockage or restriction such as a clogged filter or part-closed valve mounted on the inlet to the pump can cause it. It can also happen when the pump is having to source its water supply from a sump installed below the pump—called a “suction lift.” Finally, hot water, close to boiling point, is a likely contributor.

Why does hot water allow pumps to cavitate more easily?

When water temperatures are low, the vapor pressure of water is also low. For example, at 32 F, the vapor pressure is a fraction of 1 pound per square inch (psi). As water temperatures rise, the vapor pressure climbs. At 212 F, the vapor pressure is the same as standard atmospheric pressure. At this temperature, when the vapor pressure is the same as the atmospheric pressure, the water will begin to vaporize—turn to gas, in layman’s terms. The commonly known term for this is boiling.

>>Read more.

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A Complete Line of Pumps for Industry

Vertiflo Pump Company’s Vertical Sump Centrifugal Pumps, Horizontal End Suction Centrifugal Pumps and self-priming pumps are delivered fast, usually in half the typical lead time. Vertiflo’s vertical sump pump line offers up to 3000 GPM, 250′ Heads and 26′ depth. The horizontal end suction pump line offers up to 3000 GPM and 300’ Heads.

Vertiflo pumps are designed for nonresidential applications and currently over 20,000 are operating successfully worldwide. Vertiflo is recognized as a quality manufacturer of dependable pumps, and continues to grow and encompass new applications in the pump industry.