Unique internal cooling circuit - Hollow rotating spindle creates a positive, forced cooling path, lubricating bearing surfaces and actively purging gases & heat. Fluid is not trapped in the rear casing but seeks a low
pressure escape to the eye of the impeller through the hollow spindle. Frictional heat is conducted out of the rotating element. Any gas/air is sucked from the rear casing and expelled in a perpetual cycle.

Unique double bearing system allows the cooling circuit liquid to continually “wash” front and rear radial bearings, extending bearing life.

Inner rotating assembly - Alumina ceramic or SiC spindles are bored, turned and highly polished. The precision machined spindles form the center of the driven rotating assembly.  The impeller/magnet, keyed off this machined center, is integrally molded with this assembly for perfect concentricity and complete encapsulation of the driven magnet element. In the final step, two precision-ground ceramic thrust rings are press-fitted in perfect parallel alignment onto the front and rear of the rotating assembly. Substantially reduced hydraulic noise is a major feature of all WMD/MD impellers. Great pains are taken in the molding/fi nishing process to eliminate tangential misalignment. Hardened and plated mold surfaces yield smooth, uniform parts.

Balance holes designed to minimize axial thrust are incorporated into the WMD/MD impellers. Traditionally employed only in large process pumps, balance holes are yet another performance detail characteristic of Iwaki America WMD/MD pump engineering.

Radial bearings - High lubricity fluoropolymer bearings minimize mechanical losses typical of conventional mag drive pumps. High purity SiC radial bearings handle the most aggressive or ultrapure chemistries.  Particulate shedding is reduced to the lowest levels of any magnetic drive offering.

Thrust surfaces - Front and rear surfaces aid in hydraulic balance and minimize fl ashing. Large rear thrust surface guards against axial forces caused by cavitation or gas entrapment.  SiC surfaces are “channelled” to remain wetted, even during adverse operating conditions.

Drive magnet - Dynamically balanced barium ferrite drive magnets provide the best magnet torque, dollar-for-dollar. Depending on torque requirements, 4, 6 or 8 pole magnets are used. Die cast magnet carrier creates a fl y wheel effect, which adds to the magnet safety factor.

Motor Matching - Offering more motor/pump configurations than any other manufacturer easily allows tailored pump applications. Premium, high efficiency motors are used throughout the line. Totally enclosed, permanent split capacitor motors are compact, cool and economical. Tolerance to voltage variation without overheating and 50/60 Hz operation allows the product to be used in a worldwide market. PSC or shaded pole AC motors are standard. Brushed and brushless motors are available for DC applications.

Instructions for use can be found here

Differences with the MD Series:

• American motors are HVAC in design
• American pumps are made from rolled steel with stamped end plates, while the Japanese version is made from cast aluminium with a cast end bell
• Adapter plate causes the American pumps to be 3" longer, on average, than the Japanese pumps
• Japanese uses a custom pump design specifically for aquatic applications, whereas the WMD series pump was designed for more general applications
• Japanese pumps run cooler to the touch and slightly quieter, due to the thicker material
• American series comes with the plug pre-spliced