WMD/MD Iwaki Mag Drive Pumps
WMD and MD pumps are constructed of Glass Fiber Reinforced Polypropylene or Carbon Fiber Reinforced Fluoroplastic (PVDF)  Standard O-ring is Fluoroelastomer (FKM) - similar to Viton. Bearing is Teflon (PTFE).

1. Hollow Rotating Spindle
2. Molded Impeller
3. Fluoropolymer Bearings
4. PTFE Front Thrust Surface
5. Barium Ferrite Drive Magnets

• Unique Internal Cooling Circuit

1) Hollow rotating spindle creates a positive, forced cooling path, lubricating bearing surfaces and actively purging gases and 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 thereby conducted out of the rotating element. Any gas/air is sucked from the rear casing and expelled in a perpetual purge function.

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

• Precision Tolerance/Balancing

2) Impeller – Alumina ceramic or SiC spindles are bored, turned and highly polished. This precision-machined spindle forms the center of the driven magnet. The impeller/capsule, keyed of this machined center, is molded around the spindle/magnet assembly for perfect concentricity of the rotating element. In the final step, two precision-ground ceramic thrust rings are press fitted in perfect vertical alignment onto the front and rear of the rotating spindle. Substantially reduced hydraulic noise is a major feature of all WMD/MD impellers. Great pains are taken in the molding/finishing process to eliminate tangential misalignment. Hardened, plated mold surfaces yield smooth, uniform parts. Balance holes to minimize axial thrust are designed into some WMD/MD impellers. Traditionally employed only in large process pumps, balance holes are yet another performance detail characteristic of Iwaki Walchem WMD/MD pump engineering.

• Bearings/Thrust Surfaces

3&4) High lubricity fluoropolymer bearings minimize mechanical losses typical of conventional mag drive pumps. High purity SiC radial bearings handle the most aggressive ultrapure chemistries. Particulate shedding is reduced to lowest levels of any magnetic drive offering.

PTFE front thrust surface aids hydraulic balance and minimizes flashing. Large rear thrust surface guards against axial forces caused by cavitation or gas entrapment. SiC surfaces are "channeled" to remain wetted, even during adverse operating conditions.

• Drive Magnet

5) Dynamically balanced barium ferrite drive magnets provide best magnet torque, dollar-for dollar. Depending on torque requirements, 4-, 6-and 8-pole magnets are used.

• Motor Matching

Offering more motor/pump configurations than any other manufacturer makes for tailored pump application. 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 allow the product to be used in a worldwide market.  Motors are standard as 115V - 230V are available on most sizes.

• Two Bearing System
• Benefits :  Key placement of the bearings, at the points of greatest load, allows for reduction of the bearing surface. Reduction of the bearing surface minimizes the amount of friction (heat) generated by the rotation of the impeller. Reduction of the bearing surface also means increased efficiency in the overall operation of the pump.

• Rotating Hollow Spindle
• Benefits : Combined with our two bearing system, the hollow spindle completes our positive internal cooling loop. This design ensures a positive flow throughout the pump head and the rear casing. Our pumps run cooler, yielding longer service life.

• Encapsulated Magnet Assembly
• Benefits : Ensures maximum chemical resistance. No magnetic materials are exposed to the pumped fluid.

• NPT Male Suction Connection
• Benefits : Less cracking of the front casing due to over tightening of fittings mounted to the front casing. Should over tightening occur, the connecting pipe would simply "bottom" out on the front casing. Hose barb connections available.

• Variety of Mounting Positions
• Benefits : Our positive internal cooling loop allows you to mount our pumps in any position. Mounted "head up" or "motor up", air entrapment in the liquid end is not a concern.

• Compact Design
• Benefits :  A common request from OEM manufacturers, the WMDX series is the most compact of our pump offerings and it is small, compared with March & Little Giant

• Choice of Impeller
• Benefits :  Most sizes offer more than one impeller. The open impeller represents our "standard" flow. The "X" impeller is a closed design, enabling greater discharge pressures with no distress to the pump or system.