FlangeFlangeThe flange is designed for mounting the pump into a tank.
InstallationInstallationWhen installed in the tank, the discharge flange is located above the tank cover.
LeakageLeakageThe internal leakage return is especially important in case of dry-well installation.
Hydrodynamic balanceHydrodynamic balanceHydrodynamic balance is applied to reduce wear and noise emission.

KRAL W Series Screw Pumps

The KRAL pump for special requirements

KRAL W series screw pump is mainly used wherever dirty or abrasive media required. The cartridge case is coated with a resilient polymer. The plastic can absorb particlesto a limited extend.

Operation, materials, components

  • 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.

Special requirements

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.

Installation options

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.

Your advantages

  • Resistant, polymer-coated running casing absorbs particles
  • High pressure at low viscosity
  • Multiple installation variations available
  • Technical data
    Technical data15-2632-5455-85105-118
    Qth (1450 min-1, 0 bar)l/min15-2632-5455-85105-118
          
    Max. pressure at pressure flangebar120120120120
          
    Temperature max. pumped liquid°C    
    with radial shaft seal NBR 90909090
    with radial shaft seal FKM 150150150150
    with mechanical seal standard 150150150150
    with mechanical seal hard material 180180180180
    with magnetic coupling 300300300300
          
    Viscositymm²/s    
    min. 1.01.01.01.0
    max. 100,000100,000100,000100,000
          
    Max. pressure at suction flangebar    
    with radial sealing ring 6666
    with mechanical seal standard 6666
    with mechanical seal hard material 6666
    with magnetic coupling 6666
  • Models
    W series flange screw pump

    Universal pump for horizontal installation.

    In-tank W series screw pump

    Pressure port outside of the tank.

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