Submersible pumps (also known as “subs” or “submersibles”) are pumps that are placed inside the reservoir they are pumping. These pumps may have any number of impellers, often one in axial flow and several in centrifugal flow designs. A submersible pump is typically used when there is no available space above the liquid being pumped or when discharging through a static head is required for operation. They are also used when there is insufficient power at the prime mover to simultaneously run separate surface and submersible pumps. The most common submersible pumps include:
Single Phase Centrifugal Pump
This type of submersible pump is the most frequently used. The impeller (the exterior, rotating component) spins on its horizontal axis at about 2500 to 5000 RPM, with an output capacity of up to 20 gallons per minute (GPM), depending on the model and motor horsepower. The centrifugal pumps are suitable for pumping clean liquids without solid particles or slurries.
Multistage Submersible Pump
This multistage centrifugal pump is normally used in high head (pressure) applications with the highest head at the discharge of the last stage impeller. A motor-driven gearbox changes the direction of rotation to up-flow per stage, resulting in higher overall performance than similar-sized single-stage centrifugal pumps. These pumps are more complex than other submersibles. However, they might be suitable for medium to large unpressurized reservoirs where medium to long-term unattended operation without maintenance is required. The multistage pump is not suitable for lifting water.
Submersible Slurry Pump
Powered centrifugal pumps can move fluids containing small particles, such as slurries and sludges, but only when a certain amount of clear well-settled fluid is present in the suction pipe to separate the solids from the pumped slurry/sludge. These pumps are equipped with wear-resistant impellers, wear plates, and wear-resistant liners to handle slurries with large amounts of solids that would quickly damage a standard centrifugal pump’s components without protection.
This type of submersible is found in reservoir applications or gas mining industries.
Submersible Multistage Pump
This type of submersible pump is a multistage centrifugal pump with the highest head at the discharge of the first stage impeller. A motor-driven gearbox changes the direction of rotation upflow for each additional stage impeller, resulting in higher overall performance than similar-sized single-stage/single speed centrifugal pumps. You can find the multistage pump in reservoir applications or water supply pumping stations where medium to long-term, unattended operation without maintenance is required. The multistage pump is not suitable for lifting water.
