Most Frequently Asked Questions About Wellpointing Pumps
Monday, November 15, 2021
As you can imagine, BBA Pumps gets a lot of questions about wellpointing pumps and systems. While many of the answers are subjective, simply due to the variation of installations, we answer many of these common questions in our daily communication, for instance about fuel burn, GPM, CFM, and that piston pumps are best suited for wellpoint & sock dewatering applications.
Q. What are the advantages of wellpointing with a piston pump compared to a centrifugal pump?A. It is difficult to make a one-on-one comparison on how a piston pump works vs. a vac-assisted pump. It will turn out differently in practice because of the air mixed into the liquid; the centrifugal will very often perform a lot worse than a piston pump because the centrifugal pump cannot handle air or mixtures very well.
Nonetheless, The main answer to the question is that a PT piston pump has been specially developed for wellpointing, making it much cheaper to achieve a dry construction pit. We have listed all advantages for you in the document PT piston pump versus BA centrifugal pump.
Q. Can we use the PT series to pump down ponds, open pits, or sewage applications?A. This is not recommended due to the small amounts of solids the PT piston pump series can handle. If larger particles are present in the fluid, use a centrifugal pump with an open impeller and in the case of sewage, we recommend using a screw channel impeller.
Q. What is the CFM for a piston pump?A. The air handling capacity of a PT wellpoint pump is the same as the maximum pump capacity. In regards to the amount of air that gets pumped, be it just air or a mixture, a piston pump will be able to handle it without any damage.
Q. How much vacuum can a PT pump suck?A. This is the exact reason why the PT pump is best for wellpointing. This pump easily achieves a vacuum of up to 32 ft. (28 inHg). Don't believe it? Watch the video!
Q.How often should I change the piston cups?A. The entire pump end should be inspected regularly, the average service interval to replace the piston cups are between 3,000 hours and 5,000 hours. This will vary depending on the abrasiveness of the material being pumped. Clean water will result in extended service intervals while moving sand and abrasive materials will result in more frequent service intervals.
Q. What are the key differences between the PT150 and PT200 wellpoint pumps?A. The pumping concept is the same. The PT200 is the PT150’s big brother and that is reflected in its performance;
PT150 = 400 US gpm
PT200 = 880 US gpm
PT150 = 66 ft. / 28 psi
PT200 = 99 ft. / 43 psi
PT150 = 0.4 gallons per hour
PT200 = 0.9 gallons per hour
PT150 = 1,500 hours
PT200 = 500 hours