Whether you’re in water treatment, food and beverage, or any other industry, our metering pumps offer efficient and reliable performance. Learn more.
A metering pump can accurately measure the volume of liquid flowing through it per unit of time. Fluids can be delivered at precisely controlled rates, known as “metering.”
Although a few pump types are far more suited than most others, the phrase “metering pump” refers to the application or function rather than the specific pump type.
In addition to water, chemicals, solutions, and other liquids are common substances pumped by metering pumps. There are a lot of metering pumps that can handle a lot of pressure at the pump’s outlet. They are often manufactured to nearly constant meter flows (when averaged over time) over a broad range of discharge (output) pressure. Typically, metering pump models will have a maximum discharge pressure rating that the manufacturer stands behind. It is the responsibility of the engineer, designer, or user to verify that the pump’s pressure and temperature ratings, as well as the wetted pump materials, are suitable for the intended usage and the liquid being pumped.
A pump head and a motor are standard components of metering pumps. The pump’s head serves as the passageway for the liquid being pumped, which enters via an inlet line and exits via an output line. Typically, the pump head is powered by an electric motor.
When Do You Utilize Metering Pumps, And How Do You Use Them?
To reach a manageable flow rate, a centrifugal pump can be used in applications requiring the delivery of low-viscosity liquids at high flow rates (>1 m3/h) and low delivery pressures. Sometimes this is the best option financially. However, a positive displacement pump is required when precise metering is required. This type of pump is used to transfer fluid by mechanically enclosing and unclosing a predetermined volume of fluid several times with the use of seals or valves. The rate of administration or the precision of a single dose can be adjusted by adjusting the motor’s speed or stroke length, as the pumping action is cyclical.
Reciprocating pumps using plungers, pistons, or diaphragms have typically been employed for metering and dosing. These pumps work reliably with a constant flow rate throughout a broad pressure range. Other designs, such as peristaltic pumps or gear pumps, are now viable because of electronics and control technology developments.
Piston Pumps
Pistons power many metering pumps. Piston pumps are a type of positive displacement pump that can be engineered to pump at nearly constant flow rates (averaged over time) in the face of a wide range of discharge pressure, even at high discharge pressures of several thousand pounds per square inch.
The typical operation of a piston-driven metering pump is as follows: The piston (also known as the plunger) is a cylindrical component that may move into and out of a chamber of the same shape located in the pump’s head. Piston chamber connections are made to intake and exhaust lines. Two check valves, typically ball check valves, are installed on the pump head, one on the inlet line and the other on the output line. Flow can proceed from the inlet line into the piston chamber but not vice versa due to the inlet valve. Flow is permitted from the chamber to the output line but not the other way around. Due to the motor’s repeated motion of the piston into and out of the piston chamber, the volume of the chamber is alternately reduced and increased.
If the piston is released, a vacuum will form. When the pressure inside the chamber is low, liquid flows in through the input check valve, but the outlet valve closes when the pressure outside the chamber is high. The fluid in the chamber is then compressed as the piston advances in. As the chamber’s pressure rises, the inlet valve closes, and the outlet valve opens, releasing the liquid stored inside. The fluid is metered by repeatedly subjecting it to this pattern of suction and discharge. Back in the chamber, a toroidal sphincter-like spring compresses a doughnut-shaped seal surrounding the piston. This prevents fluid from leaking out of the pump as the piston travels in and out. After significant use, the packing or seals may wear out and require replacement. The metering rate is controlled by altering either the stroke length or the velocity with which the piston swings back and forth.
A single-piston pump sends fluid to the output during the discharge stroke. Since the piston moves at the same speed during both the suction and discharge strokes, the average metering rate over the life of the pump is equal to the average flow rate during the discharge stroke multiplied by two. When discharging, the piston in some single-piston pumps moves slowly and quickly when retracting to refill the pump head. The total metering rate is thus equal to the pumping rate during the discharge stroke.
High-pressure Chromatography Pumps
Similar to miniature piston metering pumps, high-pressure chromatography pumps are employed in HPLC and ion chromatography. The pistons are generally manufactured from synthetic sapphire, and the ball check valves include ruby balls and sapphire seats for increased durability and resistance to wear and chemicals. Maintaining a consistent pumping flow rate is preferable for getting reliable chromatograms. The pumping pace is kept as steady as feasible by employing either a single-piston pump with a fast refill or a double pump head with coordinated piston strokes.
The Peristaltic And Diaphragm Pumps
Diaphragm pumps prevent leakage at the packing or seal when metering a hazardous, toxic, or poisonous liquid. The diaphragm in diaphragm transmits the pump’s compression and decompression motions repeatedly. The liquid inside the pump is protected from the environment since the fluid cannot pass through the diaphragm. Like piston pumps, this action alters the volume of a chamber in the pump head, allowing liquid to flow through an inlet check valve when the pump is decompressing and out through an outlet check valve when it is compressing. High-pressure discharge diaphragm pumps are also feasible to manufacture. Typically, hydraulic motors power diaphragm metering pumps.
Rollers powered by an electric motor move along a flexible tube, compressing it to propel the liquid inside. Peristaltic pumps are helpful for metering at lower pressures, but the stress that can be applied to the fluid is higher than the flexible tubing can handle.
High-quality Metering Pumps, Best In The Market
The Stenner Econ T is a fully-automatic, peristaltic dosing pump.
The Stenner Econ T Automatic dosing particulate peristaltic metering pump’s most impressive feature is the ease with which it can be installed, programmed, and maintained—all within a week! This signifies that the user can set this device to run continually.
Chemicals such as sodium hypochlorite, hydrogen sulfide, boric acid, ammonium nitrate, ammonium hydroxide, acetic acid, cottonseed oil, chloroform, and many others can be injected with ease using the Stenner Econ T automatic dosing peristaltic metering pump. Don’t bother reading this if a high-tech metering pump is what you want. But if you need a reliable pump for dosing chemicals at home, this is a great option.
Diaphragm Pump for Measuring Volumes, Model Lb02sa-ptc1 by Pulsafeeder
Another well-known and dependable metering pump manufacturer is Pulsafeeder. The diaphragm metering pump model LB02SA-PTC1 from Pulsafeeder is easy to use and highly reliable.
It’s a pump with a diaphragm. So, it uses a diaphragm that rotates back and forth to transport liquids. The diaphragm metering pump, model Pulsafeeder LB02SA-PTC1, has many uses in the industry. Therefore, this is a good option among similar products if you need a metering pump for various functions.
This pump is easy to install, so you won’t have to hire an expert. Adjust the single head as needed by following the included instructions.
Pulsatron 230 Chemtech 100 Metering Pump
An additional high-quality and adaptable chemical metering pump is the Pulsatron 230 Chemtech 100. This diaphragm chemical metering pump is limited to pumping clean, particle-free liquids, as with many similar devices on the market. The pump’s lifespan will be extended as a result of this.
The Pulsatron 230 Chemtech metering pump stands apart from the competition thanks to its sealed gear train. This component increases the pump’s durability and decreases the need for repairs. Therefore, unlike with other diaphragm metering pumps, you won’t need to do regular maintenance on this machine.
With its four guided check valves, this pump is designed to accurately dispense the pumped chemical or liquid. That’s why you can trust it to deliver the required quantity of sodium hypochlorite or sodium hydroxide to your water treatment facility’s disinfection reactor. In addition to chlorine, sulfuric acid, and sodium bisulfite, many other chemicals can be pumped with this machine.
The Peristaltic Pump with the Stenner Pump 85mhp17
Stenner’s 85mhp 17 peristaltic pump is an excellent choice if you need a chemical metering pump to transport chlorine from a storage tank to the treatment facility. Chlorine is the intended fluid for this pump, although other chemicals like hydrogen peroxide, sodium hydroxide, etc., can be pumped with the right tube.
Its adjustable head is one of the pump’s most appealing features for metering chlorine. The pump’s flexible neck allows it to be set up in any orientation. Consequently, directing it toward the drain won’t be a problem.
Among the many manufacturers of metering pumps, Stenner is widely regarded as among the most dependable and long-lasting. The Stenner 85mhp 17 peristaltic pump has a high-pressure setting that may be adjusted up to 100 psi. The range of its daily gallonage output is 0.17 to 0.8. Due to its low daily pumping rate, this pump is better suited for domestic or light commercial applications than heavy industrial use.
Lb64sa-ptc1 Pulsafeeder A Plus Series Pulsatron Metering Pump
Another high-quality and dependable diaphragm metering pump is the Pulsafeeder LB64SA-PTC1 Pulsatron Series A Plus. Like other diaphragm metering pumps, this one works best with fluids with a viscosity of less than 1000cP.
It can pump many chemicals, but not particularly viscous liquids like honey. The variable output volume of this chemical metering pump is its most remarkable feature. The operator can control the number of chemicals released at any given time. The adjustment range is entirely up to the user, from zero to full power.
The PBT thermoplastic used in constructing the Pulsafeeder Pulsatron Series A Plus chemical metering diaphragm pump ensures its long service life.
This material’s high corrosion resistance makes it perfect for working with chemicals. The pump’s small form and attractive blue and black finish make it a breeze to set up. The measuring pump is also weatherproof, making it sound both indoors and out.
Diaphragm metering pump with dual manual controls, model Dc2b2ap by Pulsafeeder
Perhaps you’re wondering, “Why so many Pulsafeeder metering pumps?” Among the many chemical metering pump manufacturers, Pulsafeeder stands out for its dependable and long-lasting pumps.
If you’re looking for a reliable diaphragm metering pump, look no further than the Pulsafeeder DC2BAP. This model is more sophisticated and works best in an industrial setting.
The Pulsafeeder DC2B2AP diaphragm metering pump is robust, potent, and dependable because of its many noteworthy qualities. The pump’s high rpm, at 1725, is a big selling point for many buyers.
Since this is the case, you will be able to pump more chemicals daily than with any other metering pumps here.
The aluminum construction makes this an easy-to-carry and long-lasting tool. The SST head and fitting are other distinguishing characteristic. In addition, the pump is equipped with a straightforward control panel that enables a variety of customizations. Everything you need to set up the pump correctly is included in the package. You won’t need help from an expert because you can do it yourself by reading and following the included directions.
The Pros And Cons Of Both Piston Pumps And Plunger Pumps.
When operating, a piston pump draws in a specific amount of liquid during the suction stroke and releases that liquid during the compression stroke. The size of the pump’s plunger determines how much liquid it can move. The amount of liquid transferred is accurately known in both circumstances. However, due to the reciprocating action, the suction stroke of the pumping cycle does not result in any fluid delivery.
What Are The Pros And Cons Of Diaphragm Pumps?
In place of a piston or plunger, a diaphragm pump pushes fluid with the help of a flexible membrane. The capacity of the pumping chamber is increased when the diaphragm contracts, allowing fluid to be sucked into the pump. When you squeeze your diaphragm, you force some fluid out and reduce the volume.
Diaphragm pumps are great for pumping dangerous fluids since they are hermetically enclosed. However, the efficiency of the discharge and suction side valves and the degree of any backflow affect the precision of delivery. The pulsation in the discharge of diaphragm pumps is mitigated by having two or more diaphragms, one in the compression phase and the other in the suction phase. The air-operated double diaphragm pump is an example of such a device (AODD). AODDs are a low-cost and dependable metering technology that can operate at up to 10 bar with flows below 10 m3/hr and an accuracy of 3% acceptable. They can be used with muddy or contaminated liquids and can be run dry if necessary. In the water business, AODDs are used as metering pumps to inject additives; in the food sector, they are used to inject coloring and cleaning agents.
To What Extent Do Peristaltic Pumps Have Positive And Negative Effects?
The fluid is pumped through the peristaltic pump by compressing the area surrounded by the flexible element. One typical design uses rollers to pressurize fluids through an exposed pipe. Although peristaltic pumps have traditionally been employed as metering pumps in the laboratory and medical fields, developments in materials science have allowed for the development of robust pumps that can handle very viscous fluids, sludges, and slurries.
Peristaltic pumps have the benefit that the fluid being pumped never comes into touch with the pump itself. This feature is invaluable in settings where cleanliness is paramount, like the medical field or the food industry. All solids are manageable for peristaltic pumps. Failure can occur due to wear on the flexible elements; these should be replaced regularly to extend their useful life. Additional hoses and pumping parts help mitigate the pulsing discharge caused by the cyclical pumping action.
For peristaltic pumps, discharge pressures of up to 10 bar are usual, and typical flow rates range from 0.001 l/hour to 50m3/hour. Useful in the laboratory and the industrial setting, they are typically put to work in chemical processes and introducing thick slurry-type additives (for example, lime dosing in the water industry).
What Are The Gear Pumps’ Benefits And Drawbacks?
To move liquid, a gear pump employs the rotary motion of cogs. A vacuum is produced at the pump’s inlet when the rotating element forms a liquid seal with the pump’s casing. The pump works by enclosing the fluid it draws between the teeth of its gears or cogs as they rotate and expelling it out of the pump’s outlet.
In comparison to piston-driven pumps, gear pumps have various benefits. They work well with fluids of high viscosity and can endure high operating pressures. They are easy to use, cheap, and accurate within 0.5%. Lower than diaphragm pumps, gear pumps’ fluid delivery pulsations eliminate the high waves in piston-based pumps. Because of this, system design is simplified (no pulsation dampeners are needed), flow can be more accurately measured, and NPSH requirements can be reduced. Hermetically sealed magnetic couplings installed on gear pumps solve the leakage issues that have plagued them in the past.
An abrasive feed can wear down a gear pump by damaging the precision of its gears, bearings, and casing. The teeth, the gear face, and the paths can all experience wear and leakage. Flow slip, or the leaking of the pumped fluid from the discharge back to the suction side, occurs when wear worsens and causes a decrease in efficiency. Flow slip can significantly impact pump output since it scales with the cube of clearances inside the pump. Because of this, the precision of the meters is compromised.
In the plastics, rubber, and polyurethane industries, gear pumps are commonly used to transport chemically reactive compounds and meter additions at high pressure.
Conclusion
After reading our comprehensive review, choosing the right chemical metering pump shouldn’t be difficult. Be sure to carefully consider your needs and the intended use of the pump before making a purchase. Think about the number of chemicals you’ll be pumping and the scope of your job.
Pumping pure, potent chemicals into high-pressure systems is a specialty of diaphragm metering pumps. On the other hand, peristaltic metering pumps are excellent for transporting unclean fluids containing trapped gases or particle matter into systems operating at lower pressures. The two chemical metering pumps are sturdy and function reliably. If you’re looking for a metering pump, we hope you’ve discovered the one that works for you.
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