Isocyanates — commonly used in the paint and coatings industry — can cause a variety of short- and long-term health problems if workers are over-exposed to these highly reactive chemicals. Isocyanates can also be flammable in the presence of explosive vapors. Given their unique properties, isocyanates require a pump that handles product gently (low shearing), has strong suction capability, and offers a low-maintenance wear-compensation design. The SLC Series seal-less eccentric disc pump from Mouvex is said to feature superior suction at low speeds, ensuring minimum product is left in the connected piping prior to maintenance.
“The pump safely transfers and contains isocyanates due to its design that requires no magnets, no mechanical seals, or packing,” says Paul Cardon, industry products manager with Mouve. “The unique design allows the pump to self-compensate for mechanical wear, giving the eccentric disc pump the ability to maintain consistent flow rates over time,” he adds. In the SLC Series, the disc is pressed against the cylinder by a spring system in both the axial and radial directions. “When these parts are progressively wearing, the springs keep pressing the two parts against each other, [thus maintaining sealing],” says Cardon.
SLC Series eccentric disc pumps are ATEX-rated and TA Luft-certified to handle the most dangerous properties in the most explosive environments. The unit is self-priming and can run dry for up to 10 minutes. The SLC series is rated at up to 13.2 gallons per minute.
Service life of the SLC Series varies significantly depending on the application (duty, product abrasiveness, pressure, etc.). “Some eccentric disc pumps have already given more than 10 years of duty, some of them never needed any maintenance while some others just required a disc and cylinder exchange from time to time,” says Cardon. The operational principle can be viewed here.
Hazardous fluids can also be transferred by pumps that employ magnetic force. The Viking Mag Drive pump from Viking Pump Inc., for example, use magnetic force passing through a statically sealed canister to drive the pump. In such pumps, the outer magnet assembly is rotated by a driving shaft. The inner magnet assembly is rotated by the magnetic field produced by outer magnets rings. The two magnet assemblies are separated by a canister that also separates the pumping chamber from the pump housing.
This configuration also eliminates the need for a traditional dynamic shaft seal such as packing or mechanical seals. In turn, this eliminates the hazards and mess caused by leaking packing or mechanical seal failure, making this an ideal solution for hazardous liquids according to the company.