Tag Archives: Pump Efficiency

Flow Rate and Water Hammer Curves

Valves’ Effect on Flow Rate & Water Hammer

Flow Rate and Water Hammer Curves
Excerpt from the December 2021 Pumps & Systems Article by Pete Gaydon

Not all valves are well suited for controlling system flow rate.

Can any valve be used for controlling flow rate in a pump system, and what is the effect on water hammer?

Not all valves are well suited for controlling system flow rate. Image 1 (header image) compares the valve characteristics of various valves. You can see that the gate valve, based on its position, increases flow rate the fastest out of any of the other valves. Of the valves presented here, the plug valve provides the most consistent flow increase versus its valve position, which is ideal for throttling. In this case, a gate valve would not be good for flow control because of the lack of linear control over the flow.

Overall, the performance and characteristics of each valve will affect the magnitude of any transients developed by valve closures and openings. It is important to consider rate of flow change versus valve position and control the closure rate of the valve such that the effects of system transients (water hammer) are reduced.

Upstream Valve Closure Data

In Image 2, we have a comparison of some common valves where each valve closes over 60 seconds. The middle chart shows the pressure rising immediately upstream. The globe valve has the minimum pressure rise because the characteristics of the globe valve shown in the image above are more linear than either the butterfly or ball valve.

You can see in Image 1 that the characteristic curve of the ball valve is relatively flat coming from the bottom, with anything less than 40% open having very little effect on the flow rate. Without much change in flow until about 55 seconds, there is significant decrease in flow over the last five seconds of closure, which results in a rapid change in velocity and a high pressure change upstream. Using the ball valve would result in the greatest likeliness of a water hammer effect. This sudden rise in pressure can be damaging to equipment within the system.

>>Read more.


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.

Total Head for Pumps & Systems

Total Head for Pumps & Systems

Total Head for Pumps & Systems
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.


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.

Cavitation on a centrifugal pump impeller

What is Cavitation?

Cavitation on a centrifugal pump impeller
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.


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.

Pump Impeller Tip Speed

Wear in Centrifugal Pumps

Excerpt from the Dec. 2019 Pumps & Systems Article by Gary Dyson

Tips to recognize and reduce erosion and abrasive wear

Centrifugal pumps are sometimes used in environments where the pumped product contains suspended solids. While some pumps are specifically designed for solid handling or slurry applications, normal centrifugal pumps do not contain features to prevent performance degradation from the impact of solids.

There are a few key signs that a conventional centrifugal pump is suffering from erosive and abrasive wear. Here are assessment and mitigation strategies to be considered and applied when this occurs.

Particles are a problem in a centrifugal pump due to the way the machine adds velocity to the liquid as it passes up the impeller channels. In general, the higher the speed at the tip of the impeller, the more energy that is imparted to any particle that is suspended within the liquid. This energy can then cause damage to anything it impacts.

Pump Impeller Tip Speed

It is important to draw the distinction between tip speed and rotational speed. A small diameter impeller running at high speed could have a lower tip speed than a large diameter impeller running slowly. Tip speed is the velocity of the impeller at its outside diameter.

In general terms, the material loss by erosion is determined by the velocity of the particle cubed (Equation 1).

Equation 1:
Erosion = XC3

C is the velocity of the particle
X is a coefficient based on the liquid
being pumped

The velocity of the particle is directly associated to the tip speed of the impeller (Image 1). Lowering the tip speed of a machine has a significant impact on particle velocity and, thus, the erosive energy.

Volute Tip Wear

>>Read more.


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.

Pump Curve

Determine Power When Looking at Typical OEM’s Pump Curve

Excerpt from the Feb. 2021 Pumps & Systems Article by the Hydraulic Institute

There are two ways to estimate the power for a specific operating point.

How do I determine the power required when looking at a typical manufacturer’s curve?

A typical pump curve (Image 1) includes the pump head for various impeller trims as a function flow rate. It also includes lines of constant efficiency, power and NPSH3. There are two ways to estimate the power for a specific operating point.

Pump Curve

For the flow and head, you can see where it lines up between the lines of constant power to get an estimate. In Image 1, the design flow or 1,000 gpm and 100 feet of head will require approximately 30 horsepower (hp). From this curve, we can also see that if a higher flow rate would be needed for the appropriate pump trim, it would exceed the 30-hp line, and the next size motor would be required for full curve coverage.

For any flow and head, you can find the closest efficiency and manually calculate the power required.

For the same design point in Image 1, we can see that the efficiency will be between 82% and 85% but closer to 85%, so let’s pick 84%. For water at ambient temperature (specific gravity = 1.0), the power can be calculated using Equation 1.

Equation 1

Pump input power (hp) = Flow (gpm) x Head (ft) x Specific gravity / 3960 x Pump efficiency= (1000 x 100 x 1.0)/(3960 x 0.84) = 30 hp

>>Read more.


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.

NPSHA vs rate of flow

Considerations for Wastewater Pumps

Excerpt from the Jan. 2021 Pumps & Systems Article by the Hydraulic Institute

Hydraulic Institute on examining altitude, temperature and more when selecting a wastewater pump.

Aside from handling solid waste and sludge, what else must be considered for wastewater pumps?

Typical pumping considerations for a wastewater pump include the ability to pump solids, grit, corrosive materials, sludge, scum and smaller particles that have agglomerated into larger particles. Aside from these requirements, additional considerations should be made when selecting a pump for wastewater applications. These include the altitude, temperature, flow rate and rotative-speed limitations.

When considering altitude, it is important to know that the site evaluation for the pump installation can affect pump operation. In general, the higher the elevation of the installation, the less suction lift there is available for the pump. For pumping systems with atmospheric suction pressure, the net positive suction head available (NPSHa) calculation should be checked to include the actual atmospheric pressure at the job site.

NPSHA vs rate of flow for wastewater pumps

Altitude will also affect the selection of the pump driver and, when applicable, the variable frequency drive (VFD) because higher altitudes will result in the air providing less cooling. The reduced cooling may require the driver and VFD to be derated.

The temperature of the liquid pumped affects the ability of the pump to operate. Specifically, high-temperature liquids will have higher vapor pressure, reducing the NPSHa. If not properly accounted for, the pump may cavitate, which can cause reduced performance, physical damage to the pump components and can increase vibration.

Current wastewater pump design technology allows reliable operation of pumps with values of suction specific speed (Nss) through approximately 250 for metric units (13,000 for U.S. customary units, Nss), depending on eye peripheral velocity, materials of construction, range of operation, pumped liquid properties, and other factors.

Higher Nss values result in pumps designed with lower NPSH requirements at the same or higher operating speeds. The maximum speed for a pump (n) due to NPSHa can be calculated from the Nss formula by expressing the rotative speed as a function of NPSHa, pump rate of flow (Q), and Nss (Equation 1).

Equation 1

n = (Nss × NPSHa0.75)/Q0.50

>>Read more.


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.

Visualization of Gas-Liquid Flow Pattern in a Centrifugal Pump

Excerpt from the Feb. 2021 Vol. 13 of Measurement: Sensors research paper by LinZhao, Zhuang Chang, Zhenduo Zhang, Rui Huang, and Denghui He

1. Introduction

The centrifugal pump is extensively used in the fields of petroleum, chemical industry, nuclear power, agriculture, etc. The bubble flow is an important flow pattern that exists in the working process of a centrifugal pump. When bubbles are evenly distributed in the impeller channel, the pump performance is less affected by them. As the inlet gas volume fraction (IGVF) increases, bubbles may accumulate in the impeller, and thus, affect the pump performance. When bubbles coalesce further, it may form an air mass around the impeller inlet. With the increased gas concentration, the pump is prone to surge, resulting in a sudden drop in head, which is also accompanied by strong vibration and noise. In serious cases, the impeller channel will be blocked, resulting in “gas lock” effect, which makes the pump idle. This not only greatly reduces its service life, but also affects the normal production. Therefore, it is significantly important to study the flow pattern in the pump under bubble inflow condition for the safe and stable operation of pump.

Centrifugal Pumps

Murakami and Minemura classified four typical flow patterns in the pump impeller, i.e., the Bubble Flow (BF), the Agglomerated Bubble Flow (ABF), the Gas Pocket Flow (GPF) and the Segregated Flow (SF). For the pump operating under the bubbles inflow, the bubble behavior will affect the gas-liquid flow pattern in the pump, and thus, affect the pump performance. However, limited literature on the bubble behaviors in the pump are publicly available. Minemura and Murakami investigated the effect of the pressure gradient force, the drag force, the buoyancy force and the inertia force on bubbles motion in a centrifugal impeller. They reported that the governing factors for the bubble motion are the pressure gradient force and the drag force, and the effect of the inertia force increases as the diameter of bubble increases. Sterrett developed an analytical model for the motion of a single bubble through a pump impeller. The results showed that the Coriolis and buoyancy forces are important in describing the kinematics of gas phase.

The bubble motion is also influenced by the pump suction pressure. Barrios and Prado measured the bubble size inside the impeller channel of an Electric Submersible Pump (ESP) by using a high-speed instrumentation. They found that the majority of the bubbles inside the pump are not spherical. With the increase of the IGVF, the tendency of bubble coalescence as well as the bubble size increases. Similar results on the variation of bubble size were also reported by Cubas et al. Finally, the stagnant bubble at the impeller inlet causes the pump surging. Shao et al observed that for the BF and ABF patterns, the bubbles in the impeller rotate with the impeller, and the bubbles in the volute move along the volute channel. Once the IGVF reaches a critical value, some bubbles will flow back to the impeller near the volute tongue. When the flow pattern transits from the GPF pattern to the SF pattern, some bubbles in the discharge pipe return to the impeller near the volute tongue. When the height of the gas in the inlet pipe reaches the critical value, sometimes the bubble will flow into the volute, sometimes it will flow back to the impeller at a small velocity.

Stel et al experimentally and numerically investigated the bubbles motion in a centrifugal pump impeller. The effects of the bubble diameter and the liquid flow rate on the bubble trajectories were evaluated. The results indicated that the bubble movement is hindered by the bubble diameter and impeller rotational speed but facilitated by the liquid flow rate increasing. They also demonstrated that the behavior of the bubble inside the impeller is mostly dominated by a balance between the pressure gradient and the drag forces. This balance determines whether the bubble leaves or stays in the impeller. The bubble behaviors and their effects of the gas-liquid distribution in the impeller are still need further exploration.

2. Experimental setup and method

2.1. Experimental setup

Fig. 1 shows the gas-liquid two-phase flow loop employed in this study. The tap water and compressed air were used as the fluids. The experiment method and the parameters of the measurement devices employed in the present experiment are available in Ref. [18]. The measurement locations of the inlet pressure (Pin) and the pressure increment (ΔP) of the pump was shown in Fig. 1.

Centrifugal Pump Gas Flow

2.2. Centrifugal pump

The primary parameters of the centrifugal pump are shown in Table 1. As shown in Fig. 2, the pump inlet and the motor were designed in the same side to record the gas-liquid distributions in the whole impeller. The water flows into the pump through an annular inlet. The flow in the pump can be filmed from the hub of the impeller. The inlet part of the pump, the impeller and volute were made of polymethyl methacrylate (PMMA) (Fig. 3). The volute was designed with rectangular external shape and circular internal section to reduce the reflection and refraction of the light during the experiment, and thus, improving the shooting quality of high-speed photography. The pictures of the impeller and part of the volute are displayed in Fig. 3.

Centrifugal Pump Table 1

>>Read more.


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.

Paradigm Shift Towards Solar Powered Centrifugal Pumps

Excerpt from the Sept. 2019 article from Modern Pumping Today by Dave Namrata

Rapidly changing agricultural technology combined with constant improvement in farm machinery is leading to wide adoption of energy-efficient centrifugal pumps, creating pressure and flow in the irrigation system. Solar-powered water pumping system in agriculture is gaining popularity as an alternative to grid electricity. The modern agricultural system has led to the growing demand for irrigation solutions that reduces energy cost, improves productivity and safeguards water resource. Moreover, a reduction in the price of solar panels and components in solar power systems is driving the adoption of solar-powered centrifugal pumps and emerging as an economically viable option for irrigation.

The growing concern towards wastewater treatment in the past few years has resulted in wide application of centrifugal pumps. Rising competitiveness in the market is resulting in the development of centrifugal pump technology leading to better performance and reduction in the overall cost. From a design perspective, manufacturers of centrifugal pumps are focusing on improving the quality of shaft steel in the pumps to withstand vibration, fatigue, and stress. According to some industry experts, water shortage is likely to impact more than half of the world population by 2025. This is accelerating the wastewater treatment process across the countries.

Increasing energy costs and growing environmental awareness are motivating pump manufacturers to focus on developing energy-efficient centrifugal pumps for the end-use industries. Moreover, centrifugal pumps operating at a high speed pumping a large amount of liquid consume more power. This is leading to the integration of economically feasible and reliable solar power in the centrifugal pumping system.

Long product life and low maintenance cost of solar-powered centrifugal pumps are emerging as the perfect alternative to other pumping systems. Industries consider various factors while selecting a pumping system, such as pump lifecycle cost, including initial cost, maintenance cost and energy cost. On average, centrifugal pumps can consume around 60 percent of motor energy in the facility resulting in higher energy and maintenance costs.

Centrifugal Pumps
Centrifugal pumps generated by solar power

 

Increasing Focus on Energy Efficiency

In recent years, with an increasing cost of energy worldwide, energy efficiency is gaining attention from governments and pump manufacturers across countries. Despite various challenges, pump manufacturers are adding sustainable design features, enhancing productivity, quality, and services.

Solar-powered centrifugal pumps have gained popularity and are available on a large scale in the developed countries. However, the high initial cost of solar-powered centrifugal pumps as compared to the cost of fuel-powered pumps is the main obstacle for solar pumps in developing countries. This is driving the pump manufacturers in the developing regions to design next generation, cost-effective solar powered centrifugal pumps, eliminating the need for grid connection or fossil fuel.

Use of solar photovoltaic technology for centrifugal pumping system has gained immense popularity. Continuous reduction in solar cells cost is likely to drive the application for centrifugal pumps powered by the solar photovoltaic system in agriculture and other industries.

solar panels for centrifugal pumps
Solar panels for centrifugal pumps

With an aim to save the energy cost, replacement and refurbishing of the pumping system in water and wastewater treatment industry is on the rise. There has been a rise in the adoption of centrifugal pumps powered by solar energy in this industry.

Driven by rapid industrialization and urbanization, municipal water and wastewater industry in emerging countries is creating growth opportunities for centrifugal pumps manufacturers. However, manufacturers are facing a flood of new competition due to the increasing demand for energy-efficient pumps and stringent regulations. According to the American Hydraulics Institute, around 30 percent of the total electrical energy consumed by pumping systems can be saved by developing a highly efficient system and using appropriate pumps.

First-generation PV pumping systems using centrifugal pumps have shown significant advancements in recent years. The current solar-powered pumping technology uses an electronic system by further increasing the output power, performance and efficiency. PV modules account for nearly 60 to 80 percent of the total cost of PV system. A significant decline in the cost of PV modules across various regions has also reduced the overall cost of the pumping system. Moreover, an increase in the cost of crude oil, diesel, and gasoline has made solar powered pumps financially attractive.

There exists immense growth opportunity for centrifugal pumps in wastewater, pharmaceuticals, food and beverage, and chemical industries, as the sectors are set to grow at a stable pace in the near future. However, centrifugal pump demand will continue to be hit by the nuclear power generation, mining, and oil and gas sectors, which are likely to experience slow growth.

>>Read more.


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.

Minimum Continuous Stable Flow

Centrifugal Pump Flow Operating Regions and Impact on Reliability

Ideally, a centrifugal pump should be operated at or near its best efficiency point (BEP) flow rate in order to minimize the life cycle costs. However, all centrifugal pumps have sweet spots beyond the BEP that will yield acceptable efficiency and reliability.

Excerpt from the Sept. 2016 article from WaterWorld

There are limitations, though, on the minimum and maximum flow rates, beyond which the pumps should not be operated continuously (or for an extended period of time), in order to avoid premature failures.

A first step in avoiding these negative, low-efficiency and low-reliability conditions is to determine the pump BEP, preferred operating region (POR), and allowable operating region (AOR) flow rates. It is especially important to determine these flow regions because not all pump applications are static in nature or closely match the expected system demand. Because of this, pumps are often required to operate over a broad range of flow rates, which can adversely affect the pump efficiency and reliability.

Centrifuge Flow Reliability Factor

A pump will always operate at the flow rate where the pump head-capacity curve intersects the system head-capacity curve. This means that it is also critical to accurately determine the true system H-Q curve, in order to establish the true operating flow rates.

Once these flow regions and the true system conditions are known, actions can be taken to maximize pump operation in the POR and avoid or minimize operation outside the AOR, thus optimizing pump life cycle costs.

BEP Flow Region

Pump performance and service life are optimized around a rate of flow designated as the BEP. At the BEP, the hydraulic efficiency is maximum, and the liquid enters the impeller vanes, casing tongue (discharge nozzle), and diffuser vanes in a shockless manner. At the BEP, flow through the impeller and diffuser vanes (if so equipped) is uniform, free of separation, and well-controlled.

Minimum Continuous Stable Flow

Lower and higher flow rates cause mismatch between the flow and the impeller and casing vanes. This mismatch causes turbulence within the impeller and casing flow passages, which both block the flow passages and increases the local velocities. This increase in velocity increases vaporization (cavitation) within the liquid. The greater this resulting turbulence and cavitation, the lower the pump efficiency and reliability, and the more severe are the levels of vibration, noise and erosion.

>>Read more.


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.

What is a Centrifugal Pump?

centrifugal pump is a machine that uses rotation to impart velocity to a liquid and then converts that velocity into flow.

Excerpt from introtopumps.com

Let’s break that definition down into its components so that we can consider each one in turn:

  1. A centrifugal pump is a machine.
  2. A centrifugal pump uses rotation to impart velocity to a liquid.
  3. A centrifugal pump converts velocity into flow.

Every centrifugal pump includes an assembly of mechanical components that make operation of the pump possible. This mechanical assembly includes the pump shaft mounted on bearings, the sealing mechanism that keeps the pump from leaking excessively, structural components designed to handle the stresses and loads imposed on the pump during operation, and wear surfaces that allow the pump to be repaired and returned to its original specifications.

Every centrifugal pump includes an impeller. The impeller is the hydraulic component that rotates to impart velocity to the pumped liquid.

Every centrifugal pump includes a casing. The casing is the hydraulic component that captures the velocity imparted by the impeller and directs the pumped liquid to the pump discharge point.

At the most fundamental level, a centrifugal pump consists of just these three components:

  1. An impeller that rotates and imparts velocity to a liquid.
  2. A casing that captures the velocity generated by the impeller and transforms that velocity into a stable flow.
  3. An assembly of mechanical components that makes it possible for the impeller to be rotated within the pump casing.

>>Read more.


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.