Solinst - Model 408M -Micro Double Valve Pump
The 408M Micro Double Valve Pump has a remarkably small and flexible design. It is a pneumatic pump which operates under the same principle as the standard DVP, but uses coaxial PFAS-free PTFE tubing with stainless steel valves and filter. Small enough to fit in 1/2" (13 mm) tubing and all channels of the Solinst CMT System, the Micro DVP is ideal for low flow sampling in narrow applications. A flow rate of 20 to 200 ml/min can be obtained to depths up to 73 m (240 ft).
The Micro Double Valve Pump has a remarkably small and flexible design. It is a pneumatic pump that uses coaxial PTFE tubing to give high quality samples. At 3/8` (10 mm) diameter, it is small enough to fit in 1/2` (13 mm) ID tubing such as in Waterloo Multilevel System 5/8` open tubes, as well as channels of the Solinst Model 403 CMT Multilevel Systems. Ideal for low flow groundwater monitoring in narrow applications.
The Micro DVP is ideal for low flow sampling and narrow down-hole applications. Flow rates of 20 to 150 ml/min, are possible within the narrow applications. The Micro DVP is durable and easy to operate using the pre-sets and custom sampling capabilities built into the Solinst Model 464 Electronic Control Unit.
The Micro DVP uses coaxial PTFE tubing in lengths of 90 ft, 140 ft, and 240 ft. The pump body and filter assembly is 6" long x 3/8" diameter (150 mm x 10 mm). It is constructed of coaxial PTFE tubing with stainless steel fittings and a sintered 316 stainless steel 50 micron filter. Filters are easily cleaned and replaced. A manifold at the top end of the pump has a 3/16" (5 mm) PTFE sample tube and a quick-connect fitting for easy attachment to a Control Unit. A multi-purge sampling head is also available for use with the CMT System.
Operation
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.
Applications Groundwater sampling in:
- CMT and Waterloo Multilevel Systems
- Direct-Push/Drive-Points
- Low flow monitoring in narrow diameters
Advantages
- Only 3/8” (10 mm) in diameter
- Flexible PTFE, goes almost anywhere
- Inexpensive and readily dedicated
