- Delivery rate: 15 to 290 l/min
- Max. differential pressure: 120 bar
- Viscosity: > 1 mm²/s
- 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
- Screws: 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 be delivered at high pressure and contain abrasives, mostly metal residues.
Due to the innovative design, and especially the casing coating, the advantages of the KRAL 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 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 are pumped with no problem. The KRAL machine tool coolant screw pump can be supplied for dry or wet installation. A mounting flange has already been provided for vertical wet installation.
Compared with other screw pump principles, KRAL screw pumps have a number of oustanding qualities. The screw pump delivers continuously with a low pulsation rate and noise level. They achieve high flow rates even in small sizes. Cooling lubricants are difficult liquids with viscosities as low as 1 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 W series offers many advantages when pumping water-soluble coolant emulsions.
The KRAL W series screw pump can be designed for dry or wet-well installation. For a vertical wet-well installation, a mounting plate is provided.
- Technical data
Technical data 15-26 32-54 55-85 105-118 Qth (1450 min-1, 0 bar) l/min 15-26 32-54 55-85 105-118 Max. pressure at pressure flange bar 120 120 120 120 Temperature max. pumped liquid °C with radial shaft seal NBR 90 90 90 90 with radial shaft seal FKM 150 150 150 150 with mechanical seal standard 150 150 150 150 with mechanical seal hard material 180 180 180 180 with magnetic coupling 300 300 300 300 Viscosity mm²/s min. 1.0 1.0 1.0 1.0 max. 100,000 100,000 100,000 100,000 Max. pressure at suction flange bar with radial sealing ring 6 6 6 6 with mechanical seal standard 6 6 6 6 with mechanical seal hard material 6 6 6 6 with magnetic coupling 6 6 6 6