| | | Advantages and characteristics ■ Pulsation-free flow of liquid ■ High dosing accuracy Pumping hot liquids A hot liquid causes expansion in the pump and (usually) a reduction in the viscosity of the liquid. Gear pumps with a seal can pump liquids up to a maximum temperature of 315°C if the cogwheels are made of metal or carbon, or when carbon wear plates and bearings manufacturer, and seals with carbon are used. When selecting the temperature, information is used to see what effect this temperature could have on the materials. The cogwheels can also be thinned down lengthwise and in their diameter to absorb the thermal expansion. The magnetically linked gear pumps can pump liquids with a maximum temperature of 287°C and can be constructed in three different magnetic materials, ceramic, samarium cobalt and neodymium iron. The magnets are oversized because the temperature reduces the strength of the magnets. Pumping viscous liquids The Verdergear pump series 3 is extremely well suited to pumping viscous liquids. Because the viscous product fills up the space in the pump and minimises the internal slip or even eliminates it, high dosing accuracy occurs. The necessary motor power when pumping a viscous liquid can be reduced when the cogwheels are thinned down and the rotational speed reduced. Pumping thin liquids When pumping thin liquids with a very low viscosity the materials will be subject to heavy wear and tear and slippage will occur in the pump. With the Liquiflo pumps it is possible to pump liquids with a viscosity of 0.3 cP. When pumping thin liquids the surfaces between the bearing/axle and the cogwheels will only be minimally lubricated, and this causes a higher degree of wear and tear. To prevent greater wear and tear tungsten carbide axles, silicon carbide bearings and specially developed front and back casings can be used. | | |