Piston Wellpoint Dewatering Pumps

PRODUCTS > Piston Wellpoint Dewatering Pumps

Thompson’s piston wellpoint dewatering pump is highly efficient. It produces a pulsating vacuum that prevents clogging, requires only a single-cylinder engine and does not contain any vacuum pumps or associated oiling systems typically required in other wellpoint pumps. The self-priming, double-acting design has an efficiency rating of over 90%, which allows for low motor capacity. The unit is extremely cost-effective to operate and can run for more than one week on a single tank of fuel.



The double-acting piston pumps convert rotational energy applied to the pulley to linear motion to a set of pistons by two conically milled gears mounted on either side of the crankshaft. A vacuum is created inside the cylinders from the motion of the pistons. On the piston upstroke, water is drawn into the cylinder as the suction valve opens and the delivery valve closes allowing the water to be drawn into the cylinder. On the down stroke, the force of the piston causes the suction valve to close and the delivery valve to open, forcing the water out through the discharge.


  • Flows up to 400 gpm
  • Discharge heads up to 66 feet
  • Suction lift up to 28 feet
  • Self-priming, positive displacement pump with high air handling capability of 53 cfm
  • Rugged, corrosion-resistant rotors and wear plates allow for extended use and operation
  • Efficiency rating of up to 92%
  • Extremely low fuel consumption (less than 5 gallons per day)
  • On-board stone catcher with cleaning port to protect the pump
  • Double-sealing piston rod prevents oil leakage
  • Ease of use and maintenance
  • 12-month limited warranty covers manufacturing defects in materials and workmanship


Consult factory for other versions & options.

Unit Model Size (In.) Max Head (Ft.) Max Capacity (GPM) Max Solids (In.)
6PW 6 66 400 Filtered Water Only


These pumps are available skid-mounted or trailer-mounted.

These pumps are offered with a diesel engine or an electric motor.

Silent Knight®
Sound-attenuated canopy reduces pump sound levels to or below 69 dBA. Fully insulated, weather-proof and lockable, the Arctic Night® variation is ideal for extremely cold temperatures.