Pumps failing through running dry, or becoming damaged due to pumping corrosive liquids are not uncommon problems, however both these costly issues can be eliminated by using Hydra-Cell seal-less diaphragm pumps from Wanner.
All pumps with dynamic seals could fall foul of the dry running problem. The liquids that these pumps move also act as the lubricant and cooling system for the pump. Friction of the mechanical seal faces running together without lubrication, or the shaft packing running against the shaft without cooling by liquid seepage causes overheating, seizure and catastrophic failure. Failure from running dry can also be attributed to an operator’s error, being too busy to notice that the feed tank is empty. These mistakes cost industry many millions of pounds each year.
Hydra-Cell high pressure pumps are different. They operate with hydraulically balanced diaphragms and therefore have no dynamic seals to overheat and fail during dry running. Wanner claims that Hydra-Cell pumps can run dry indefinitely without problem.
Hydra-Cell’s seal-less design enables them to pump liquids that contain abrasive particles and other non-lubricating fluids that would cause damage to pumps with mechanical seals.
Corrosive liquids can also be pumped easier with a Hydra-Cell pump, due to the availability of an extensive range of fluid end materials that can handle almost any liquid, and thus avoid potential pump damage.
Hydra-Cell pumps have been available for some time with the fluid end machined from Kynar® PVDF, a high temperature engineering fluoropolymer famed for its high purity and outstanding resistance to a wide range of aggressive, corrosive chemicals… notably concentrated sulphuric and hydrochloric acids. Now, Wanner International is able to offer these pumps with stainless steel DIN flange fittings and Kynar mating surfaces, making Hydra-Cell pumps even easier to incorporate into corrosive fluid systems.
“Kynar pipe work is used extensively in the chemical processing, pulp & paper and semiconductor manufacturing industries,” said Paul Davis, Managing Director of Wanner International. “Offering a Kynar/DIN flange combination will potentially increase the acceptance of Hydra-Cell pumps in these industries.”
Kynar liquid heads are available for Hydra-Cell G03, G10, G20, G25 pumps covering a range of performance from 3.79 lpm to 76 lpm at pressures up to 24 bar (350 psi) and are also available on the Hydra-Cell metering pump range.
Exceeding the performance requirements of API 675 in terms of repeatability, linearity and steady state accuracy, the Hydra-Cell pump’s multi-diaphragm configuration generates virtually pulse-less flow, removing the need for dampeners in most applications.
Because Hydra-Cell pumps are true positive displacement pumps, flow rate is directly proportionate to input shaft speed and virtually independent of system discharge pressures. This allows precise flow control to be achieved using mechanical speed variators or variable frequency drives; both of which are available from Wanner International.
