The pump for special requirements.
KRALs W series pump is mainly used wherever a dirty or abrasive media is required. The cartridge case is coated with a resilient polymer. The plastic can absorb particles due.

Operation, materials, components.



• Delivery rate: 15 to 290 l/min.
• Max. differential pressure: 120 bar.
• Viscosity: > 1 mm2/sec.
• Max. temperature: to 180 °C, magnetic coupling to 300 °C.
• Installation: Wet or dry.
• Spindle housing: Nodular cast iron EN-GJS-400, polymer coated or other material
       options.
• Spindles: Steel, nitrided.

Water soluble machine tool coolant can be a very difficult pumping service to handle. The fluids have a very low viscosity of only about 1 mm²/s, must by delivered at high pressure and contain abrasives, mostly metal residues.

It is due to the innovative design, and especially the casing coating, that the advantages of the KRAL three screw pump can be successfully applied to machine tool coolants. KRAL coats the running casing with a resistant polymer. This synthetic material can absorb particles. According to specifics of the application other materials can also be used.

Water soluble machine tool coolants are pumped at high pressures of up to 120 bar. Only at such high pressure is sufficient cooling and flushing of the chips accomplished. The balancing cylinder of the three screw pump has orifice insertions to reduce the leakage rate, therefore efficiency remains high.

The screw material and the casing coating have been designed for improved sliding properties in such a way that low viscosity fluids is pumped with no problem. The KRAL machine tool coolant three screw pump can be supplied for dry or wet installation. A mounting flange has already been provided for vertical wet installation.

Special requirements.
Compared with other three screw pump principles, three screw pumps have a number of oustanding qualities. The three screw pump delivers continuously with alow pulsation rate and low noise level. They achieve high flow rates even in small sizes. Cooling lubricants are difficult liquids with viscosities as low as mm²/s. The fluid must be delivered at high pressure, and contains abrasives, mostly metal residues.

Thanks to the innovative design, particularly in regards to the case materials, the KRAL three screw pump offers many advantages when pumping water soluble coolant emulsions.

Contamination? No problem!
Metal residues in cooling lubricants can cause abrasive damage to the three screw pumps internal surfaces. When precautions are not taken, the case, the spindles and the ball bearing are affected. KRAL coats the case with a resistant polymer, this synthetic material can absorb particles within limits. Depending on the liquid used, other materials can also be provided. Additionally, the three screw pump is provided with a permanently lubricated outside bearing which has no contact with the medium.

Installation options.
The KRAL cooling lubricant three screw pump can be designed for dry or wet-well installation. For a vertical wet-well installation a mounting plate is provided.

Your advantages:



• Resistant, polymer-coated running casing absorbs particles.
• High pressure at low viscosity.
• Multiple installation variations available.