Choosing a Magnetic Drive Chemical Transfer Pump

Choosing a Sealed vs. Sealless Centrifugal Chemical Transfer Pump

A centrifugal chemical transfer pump is designed as either sealed or sealless.

Sealed Centrifugal Pump

A chemical transfer pump with a mechanical seal can offer the perfect solution for applications that require the transfer of liquids that contain solids. A second advantage of these pumps is the cost. Compared to sealless pumps, these styles are typically available at a lower price point.

Sealless Centrifugal Pump / Mag Drive Pump

How does a Sealless Centrifugal Pump / Mag Drive Pump work?

Operating Principle

The magnetically-driven design of the pump eliminates the need for a seal – so there are no leaks. The magnetic connection between the motor-mounted outer drive magnet and the drive magnet located inside the pump transmits torque from the motor to rotate the impeller, for effective, efficient operation.

Mag Drive Centrifugal Pump Design

A mag drive centrifugal pump has several innovative design features to optimize its performance.

Magnet Technology/Sealless Connection

Powerful neodymium magnets are used to drive the impeller, for leak-free operation with no environmental emissions, no mechanical seal costs, and no seal support systems.

Corrosion-Resistant Design

Wetted components are all corrosion-resistant non-metallic materials, to withstand the harshest environments.

Flooded Suction versus Self-priming

Flooded suction pumps are gravity-fed from a liquid source that is above the pump’s centerline, eliminating the need for priming, which can speed up operations. This type of pump is widely used in many applications.

Self-priming pumps are ideal for applications where the liquid source is below the pump’s centerline. Their design lets the pumps retain fluid in their housing, allowing them to create a partial vacuum in the suction line. Atmospheric pressure pushes liquid up the suction line to the pump. Once initially primed, the pump will continue to operate without the need to reprime.

Easy-set Outer Drive

Provides measurement-free drive installation that allows perfect magnet alignment every time, for maximum power performance.

Self-priming Features

A self-priming design eliminates the need for troublesome internal check valves or external foot valves to maintain prime.

1. Improves Productivity

Every time a mechanical seal requires replacement, it affects operations in several ways. The first (though perhaps least) impact, is the cost of the new seal. The second is the labor to uninstall the pump, replace the seal and reinstall the unit. Last, this maintenance cycle may well incur downtime – potentially causing a line or system shutdown – risking delayed or lost production and its impact on the bottom line.

If this maintenance must be performed on an emergency basis, it can disrupt operations more significantly. This adds the associated costs of delayed or unfilled orders, customer dissatisfaction, safety hazards, and potentially overtime labor costs for repair technicians. Mag drive pumps eliminate this weakness and risk. Due to their innovative design, mag drive pumps do not require a mechanical shaft seal and are free of any openings in the back of the pump allowing for a hermetic seal. The magnetic drive design eliminates the direct connection of the motor shaft through a hole in the back of the pump to the rotating impeller assembly inside the pump’s interior.

This is key for two reasons. First, if the pump has no seal, a potential leak point is eliminated. Second, pumps with no seal never need a replacement seal. These two factors can drastically reduce cost in parts and labor over the life of the pump – and have a dramatic effect on the bottom line.

2. Enhances Safety

Mag drive pumps are often used for fluid transfers that involve toxic chemicals. If pumps used in these settings leak, exposure to the chemicals can put employees at risk. This exposure could happen suddenly with a drastic leak, or over time, as liquid or fumes slowly escape through a failing seal.

Finish Thompson mag drive pumps prevent this leakage, greatly enhancing worker safety. Employers can rest assured that their labor force is protected from toxic leaks that could occur with other pump styles.

3. Prevents Fugitive Emissions

Volatile organic compounds (VOCs) and volatile hazardous air pollutants (VHAPs) are a top concern for any facility that uses pumps for chemical transfers. If a pump doesn’t effectively prevent leaks, these fugitive emissions will wreak havoc on the operations.

Not only could these emissions prove dangerous to employees and the public, pump owners are liable and are at risk of failing compliance checks. Mag drive pumps prevent fugitive emissions, so companies can remain compliant with local, state, and federal health and safety standards. This increases overall plant safety and reduces the likelihood of non-compliance fines or shut-down orders.

4. Runs Dry

One of the most common causes of pump failure is running dry. Due to operator error or system upset, pumps may be put in the position of continuously running without fluid. For many pumps, running dry can quickly damage or even destroy a pump.

This isn’t the case with some mag drive pump designs. Many Finish Thompson mag drive pump designs can run dry for hours without issue. In production applications where pumps are not under constant supervision, this ability to run dry can eliminate the risk of pump failure and the associated costs.

5. Resists Corrosion and Simplifies Selection

Mag drive pump technology is proven to withstand even the most corrosive and hazardous fluids. This durability makes mag drive pumps ideal for extremely corrosive applications that would be too challenging for many pump designs.

Because of this resilience, fluids that would be far too harsh for other pumps are not a problem for mag drive designs. They offer a versatile option for tough jobs that require tough solutions. In addition, pump selection can be complex. A variety of factors must be considered to choose the correct pump for the desired application and adding seal options to the mix (seal type, seal faces and elastomer options, for example) just makes pump selection more complicated. Mag drive pumps simplify the selection process.


Looking to select the best option for your chemical transfer pump? Look no further and contact us here.