Solinst 408M Micro Double Valve Pumps

  • Small and Flexible Design Only 10mm in diameter
  • Range of Tubing Lengths The coaxial PTFE tubing comes in lengths of 90 ft, 140 ft, and 240 ft
  • Easy to Operate Easy to operate using a 464 pump control unit with pre-sets and custom sampling capabilities
  • Perfect for Low Flow Sampling & CMT Multilevel Systems
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The Micro Double Valve Pump is a pneumatic pump that is ideal for use in narrow diameter boreholes when doing low flow sampling. Rather than using a bladder, it uses coaxial PTFE tubing that comes in lengths of 90 ft, 140 ft, and 240 ft. Because of its flexibility and small size, the Micro Double Valve Pump is incredibly easy to transport and install. It was designed to be small and flexible. With a diameter of only 3/8” (10 mm), it is compatible with 1/2” (13 mm) tubing and all channels of Solinst Model 403 CMT Systems.

The Micro Double Valve Pump is ideal for low-flow sampling in narrow boreholes or wells. The Micro DVP provides flow rates of 20 to 150 ml per minute without producing excessive purge volumes. When used with the Solinst Model 466 Electronic Control Unit, pre-sets and fine-tubing capabilities make the Micro DVP easy to operate.


Formation water enters through the Micro DVP's filter due to hydrostatic pressure in the inner PTFE/FEP tube and the annulus of the coaxial tubes. To close the lower check valve and force water into the sample tube, drive gas/air is then cycled down the annular space located between the two tubes. The pump then vents so that new formation water is able to enter both tubes under hydrostatic pressure. At all times, the pressure of gas/air is monitored and controlled to ensure that the air/water interface is never able to enter the pump's body. The pressure/vent cycle is then repeated to bring a high-quality sample to the surface in a regulated manner.

It is important to note that the Micro Double Valve Pump was designed to operate with 2 ft (0.6 m) head of water or more over the intake.

Manufactured by: Solinst
Model: Solinst 408M Micro Double Valve Pumps

Services offered for this product

  • Sales
  • Rental
  • Installation
  • Calibration
  • Maintenance


CMT and Waterloo multi-level systems
Direct-push/drive points
Low flow monitoring in narrow diameters


Diameter 3/8” (10 mm)
Material Coaxial PTFE/FEP tubing stainless steel fittings and a sintered 316 stainless steel 50 micron filter.
Pump Body and Filter Assembly Dimensions 6” x 3/8” (150 mm x 10 mm).
Pump Manifold
Diameter 3/16” (5 mm)
Material PTFE sample tube and a quick-connect fitting for easy attachment to a control unit.


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