Solinst Model 407 [117209] Stainless Steel Bladder Pump With PTFE check balls, 1.66" x 2 ft. The Solinst Bladder Pump features a new design providingconsistent, high-quality samples in all types of applications. It offersexcellent performance and reliability. With Solinst Bladder Pumps,there is the assurance that there is no air/water contact duringsampling. It meets the most rigorous US EPA standards for VOCgroundwater monitoring.The bladder guarantees that drive air or gas does not contact thesample, thus avoiding degassing or contamination. Solinst BladderPumps are rugged and long-lasting. Santoprene® bladders areideal for dedication, however, the new easy-to-replace bladdercartridges are excellent for those who prefer to change bladdersafter each use. The bladder and intake filters are simply replaced inthe field in just a few minutes—no special tools are required.Excellent for either regular flow or low flow sampling, the stainlesssteel pumps can lift from depths up to 150 m (500 ft) below grade.The new PVC Bladder Pump operates up to 100 ft (30 m) belowgrade. 

Low Flow Purge and Sampling : Low flow groundwater sampling offers excellent quality samplesby reducing turbulence. It also lowers purge volumes, thusreducing groundwater sampling time and disposal costs.When using a Solinst 464 Electronic Pump Control Unit, theSolinst Bladder Pump can be adjusted to provide a continuousoutput of 100 ml/min or less. The use of a Flow-Through CellSystem during low flow sampling allows the continuous analysisof purge water in-line as it flows, so groundwater sampling canbegin as soon as the readings stabilize. Packers are also available to further reduce groundwater purgevolumes, speed up sampling times, and lower purge waterdisposal costs.