Operation, Applications and Advantages


Formation water enters through the filter under hydrostatic pressure into both the inner PTFE tube and the annulus of the coaxial tubes. Drive gas/air is cycled down the annular space between the two tubes to close the lower check valve and push the water up the inner sample tube. The pump is then vented to allow new formation water to enter both tubes under hydrostatic pressure. Air/gas pressures are carefully controlled at all times to ensure that the air/water interface never enters the body of the pump, resulting in high quality samples. Repeating the pressure/vent cycle brings the sample to the surface at a controlled rate. The Micro DVP operates with 2 ft (0.6 m) or more head of water above the intake.



Groundwater sampling in:

  • CMT and Waterloo Multilevel Systems
  • Direct-Push/Drive-Points
  • Low flow monitoring in narrow diameters


  • Only 3/8” (10 mm) in diameter
  • Flexible PTFE, goes almost anywhere
  • Inexpensive and readily dedicated

408m micro double valve pump