Pro Series External Pump Features:
Money saving high efficiency pump and motor units
Unions are included
Long life corrosion resistant Stainless Steel shaft seals
Easy servicing and replacement parts available
1725 rpm motors
Totally enclosed for excellent protection and long term reliability
Constructed from non-corrosive materials for years of outdoor performance
Pump and motors are designed for quiet operation
Continuous duty operation
Double sealed bearings
Stainless Steel shaft and hardware
Compatible with HydroClean™ Pond Skimmers and HydroChamber™ Pondless Pump Vault
3 year limited warranty (for freshwater applications)
Made in the USA
External Pump: Also Known as Centrifugal Pump or Inline Pump
Protect your pump investment from low water burn out with our
Auto ON-OFF Float Switch
The external pump is a pump that sits outside the water. The external pump pumps water from a suction pipe with the “wet” end of the pipe under water. Whereas a submersible pump is submerged in the water that it is pumping. A submersible pump requires electricity under water. An external pump sits outside the water with no electricity in the water. An external pump helps protect from potentially dangerous oil leaks or electrical hazards.
An external pump is much more energy efficient than submersible pumps. Submersible pumps utilize an impeller turning inside a volute. The impeller “pushes” water out the volute exit. The exiting water creates a vacuum that sucks more water into the volute.
The impeller is significantly smaller in diameter than the volute. This allows for solids to pass around the impeller and out of the volute. While this provides the benefit of clog resistance, it requires more energy to move water due to the size difference between the impeller and the volute.
An External Pump is More Efficient at Pumping Water. Therefore using less electrical power to move the same amount of water. Whereas a submersible pump uses an impeller spinning inside a much larger volute, an external pump uses impeller that is virtually equal in size to the a casing instead of a volute.
An external pump uses a shaft-driven hollow impeller that rotates inside a casing. Liquid flows into the suction port (inlet) in the center of the impeller. As the impeller spins it forces the water outward towards the casing where it is then directed to the outlet port. All the water that is pulled into the hollow impeller is forced to the discharge port.
External Pump Lasts Longer Than a Submersible Pump
A submersible pump is underwater and exposed to water pressure trying to enter the pump motor. An external pump is not underwater and therefore not exposed to water pressure.
A submersible pump has an impeller shaft exiting the motor housing. The shaft rotates the impeller. Mechanical seals surround the impeller shaft to keep water out of the motor housing. But over time, these seals eventually wear out. Worn seals let water leak inside the electrical motor. The first symptom of water getting into the electrical motor is a tripped G.F.C.I. circuit. When water enters an electrical motor it will need to be replaced.
Like the submersible pump, an external pump has an impeller shaft that exits the motor housing. The shaft has mechanical seals that surround the shaft. But unlike the submersible pump, if an external pump’s seal wears out, water will not leak into the electrical motor. Simply replace the seals and continue operation.
Another way external pumps last longer than submersible pumps is their operation RPMs. Submersible pumps typically operated at 3,500 RPM. C Series external pumps operated at just 1,750 RPM.
Another important point is that running an external pump at 1750 RPM instead of 3500 RPM reduces wear on seals and bearings by almost four times. However, centrifugal pumps running at 1750 RPM require much larger casings and impellers than submersible pumps running at 3500 RPM and therefore, cost considerably more money.
An external pump cost more upfront, but last much longer than submersible pumps. Also, an external pump uses a fraction of the power of a submersible pump for the same water pushed. So the cost of ownership of an external pump is much lower than the cost of owning a submersible pump.
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