Q.E.D. Environmental Systems, Inc., has produced a smaller diameter format of its Well Wizard dedicated bladder pumps. The company say the ST1000, being 0.80” (20mm) OD, can sample wells as small as 1” diameter at depths over 600 feet (183m), which is far deeper than other small diameter bladder pumps. Further, you can sample wells at almost unlimited depth with its optional drop tube inlet kit. This pump also fits larger wells with partial obstruction.
It has a 316 stainless steel construction and uses QED’s exclusive DuraFlex PTFS bladder formulation. The pump also uses a QED twin bonded tubing, specifically, HDPE that is either teflon-lined or all teflon. QED is so confident in the resilience of this pump that it provides a 10-year sampling pump warranty.
The pump has an operating pressure of up to 300 PSI. It also supports flow rates up to 474 milliliters per minute (ml/min). Further, the pump achieves low flow sampling accuracy that is EPA accepted.
These pneumatic bladder pumps are specifically designed for superior low-flow sampling performance. They operate with a unique, gentle action ideal for low-flow sampling. Their timed on/off cycles of compressed air also alternately squeeze the flexible bladder to displace water out of the pump, and then release it to allow the pump to refill by submergence. This all occurs without creating any disturbance that could affect sample chemistry.
According to QED, these pumps run easily at low rates for extended times, without having some of the problems associated with other pumping techniques. For example, there is no overheating of high-speed electric pump motors, a problem that can alter samples and ruin pumps. There is also no churning action, which is seen in bailers or inertial-lift samplers that increase turbidity. Degassing of dissolved volatile contaminants is also avoided, as there is no suction. Moreover, the pump helps protect against disturbance or the risk of cross contamination, as the bladder prevents contact between the pump drive air and the sample, and the down well equipment is permanently dedicated to each well.
