A dewatering pump that is the wrong type or size looks fine on day one. It then clogs, wears out early or cannot keep up with the inflow. Choosing well starts with a clear definition of the duty.
This guide lists what to establish before you ask for a quotation, explains the main pump types, and highlights common selection mistakes.
Define the duty first
- Flow rate: the volume you must remove, including peak inflow after heavy rain.
- Total dynamic head: the vertical lift plus friction losses in the pipework, and the discharge distance.
- Solids: particle size, concentration and how abrasive they are.
- Fluid: temperature, pH and chemistry, which decide the materials of construction.
- Power: grid, diesel or hydraulic, and whether it is available where the pump will sit.
- Installation: fixed, portable, or in a sump or flooded working.
Self-priming centrifugal pumps
A self-priming centrifugal pump can clear air from its suction line and start pumping without being filled by hand. It sits above the water, so crews do not enter sumps and electrical equipment stays dry. This is why self-priming solids-handling pumps, such as Gorman-Rupp's Super T and Ultra V Series, are widely used for pit dewatering, slurry transfer and trash handling. Their suction lift is limited, so they suit sumps and ponds that can be reached from above.
Submersible pumps
A submersible pump sits in the water, which avoids suction limits and suits deep sumps, shafts and flooded workings. For underground coal and other gassy environments, equipment must carry the right approvals. Gorman-Rupp offers MSHA-approved submersible models for those applications. Confirm the approval that your regulator and mine plan require.
Engine-driven and packaged systems
- Engine-driven pumps keep working where there is no grid power, and suit remote sites and emergency dewatering.
- Hydraulic piston pumps such as the SludgeKat move heavy sludges and slurries that choke centrifugal pumps.
- Packaged lift and booster stations arrive pre-engineered and factory tested, which cuts field assembly time.
Common selection mistakes
- Sizing for average inflow instead of peak inflow.
- Ignoring friction losses, so the pump cannot deliver the required flow at the real head.
- Underestimating solids size and abrasiveness, which shortens wear-part life.
- Choosing a pump without a plan for spares and servicing.
- Overlooking the atmosphere classification for underground use.
Dewatering is also a safety control
L.I. 2182 regulation 178 does not allow stagnant water to remain on floors in use, and requires practicable precautions when draining accumulated stagnant water from a winze so that noxious gases do not pollute the mine atmosphere. Reliable pumping is part of keeping workings safe, not only productive.
This is a plain-language summary for general information, not legal advice. Regulation numbers refer to L.I. 2182. Always check the current regulation text and Minerals Commission guidance for your operation.
Frequently asked questions
What is the difference between a self-priming pump and a submersible pump?
A self-priming pump sits above the water and draws it up, so it can be serviced without entering the sump. A submersible pump sits in the water and pushes it out, which suits deep or flooded locations.
What do you need to size a dewatering pump?
Flow rate, total dynamic head, solids size and abrasiveness, fluid properties, available power and the installation type. With these, a pump, driver and configuration can be recommended.