Pumping polyols and isocyanates

According to Wanner, isocyanates, when exposed to air, tend to form crystals that generate premature wear in pumps with dynamic seals while polyols, especially those containing abrasive fillers, are equally destructive to seals and bearings. The Hydra-Cell multi-diaphragm pump has no dynamic seals and consequently handles abrasive particles with ease, significantly reducing maintenance costs, says the company.

Now with new PTFE diaphragms, chemical compatibility and service life are no longer concerns. Hydra-Cell pumps with these new diaphragms have been tested extensively and shown to be able to operate reliably at full flow under flooded suction conditions, says Wanner.

Meeting the performance standards of API 675, Hydra-Cell pumps are highly accurate and repeatable, ideal for dosing and injection duties. Being completely contained, without dynamic seals, they provide no leak paths for potentially harmful chemicals and their multi-diaphragm design ensures low shear, low pulsation delivery.

“The service life of the new PTFE diaphragm is now extended to 240 million cycles; 4,000 h @ 1,000 rpm,” said Nick Herrington, Marketing and Technical Support Manager. “This brings diaphragm replacement into line with regular maintenance cycles.”

Hydra-Cell pumps are highly efficient, heavy duty pumps used for liquid transfer, metering, injection, spraying and dosing of the widest range of liquids including chemicals, solvents, acids, hydrocarbons, natural gas liquids, alkalis, polymers, aqueous ammonia, resins, slurries, wettable powders recycled or dirty liquids etc. Hydra-Cell positive displacement, unique multi-diaphragm, seal-less pumps can handle corrosive, non-lubricating and abrasive liquids and slurries and can even run dry without suffering damage.