Solinst - Model 404 -Inertial Sampling Pump

The Inertial Groundwater Sampling Pump is a simple, reliable inertial pump that provides a cost effective sampling option for groundwater monitoring. The Pump consists of a riser tube fitted with a one-way foot valve. It can be easily operated manually, or by using a surface pumping mechanism. The tubing and foot valves come in various sizes suitable for varying well diameters and sampling applications. Effective to depths of 200+ ft (60+ m) in 0.4` - 6` ID wells (12 mm - 150 mm).

The Inertial Pump is a simple, reliable inertial pump that provides a cost effective sampling option for groundwater monitoring.

The Pump consists of a riser tube fitted with a one-way footvalve. It can be easily operated manually at shallow depths, or by using a surface pumping mechanism. The tubing and footvalves come in a range of sizes suitable for most well diameters and sampling applications. A 1/4" (6 mm) Mini Inertial Pump is available for sampling inside CMT Multilevel Systems.

The Inertial Pump is a simple alternative to using a bailer. Like a bailer, the key part is the check ball which is located in the foot of the pump. As such, the Inertial Pump is often referred to as a `footvalve`.

To obtain a sample, hand-thread a footvalve onto the tubing, and then lower to the desired depth in a well or borehole. Repeatedly lower and raise the assembled tubing and footvalve approximately 6` - 12` (15 - 30 cm). A slug of water enters the tubing on the downward stroke and is retained, as the valve closes, on the upward stroke. This enables the water to gradually rise in the tubing and discharge at surface.

It is very easy to operate the pump by hand, but if preferred, Surface pumping mechanisms powered manually, or by gasoline or electricity are available. 

• Easily operated by hand
• Ideal for well development
• Operates to 200+ ft. (60+ m)
• For 0.4` - 6` ID wells (12 mm - 150 mm)
• Efficient purging rates, and high quality samples
• Essentially maintenance free

• Low cost
• Avoids cross-well contamination
• Eliminates repeated pump decontamination
• Avoids costly field and wash blanks
• Reduces time in the field
• Fast, easy operation

 Riser Tubing

High density polyethylene (HDPE) tubing is most frequently used. It is low cost, provides high strength and durability, and good sampling properties. Available in various sizes, the tubing comes in coils of 100, 200, or 500 ft. (30, 60, or 150 m). PTFE tubing is also available.

Footvalves

Footvalves consist of a check ball inside the valve body, and are available in Delrin or stainless steel, in a variety of sizes from 5/8" to 1" (16 mm to 25 mm) diameters. Tapered threads enable the footvalve to self-tap onto either end of the riser tubing.

The Mini Inertial Pump (403 MIP) consists of two stainless steel inserts and a check ball that are easily installed inside the 1/4" x 0.17" (6 mm x 4.3 mm) tubing.

Flow Rates

Flow rate is a function of the momentum generated in the tubing. It varies with tubing length, submergence depth of the footvalve, flexing of the tube, and the rate at which the tubing is pumped.

• Up to 7.6 L/min (2 gpm) with 5/8" x 1/2" (16 mm x 12.5 mm) tubing

Higher volumes are obtained with the use of electric or gasoline powered surface pumping mechanisms.