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Selecting a pump requires that you know the flow rate, material you are pumping, temperature, and required discharge pressure.



Generally the flow rate, liquid, and temperature parameters are usually known for an application. Temperature and material being pumped are important in selecting the pump type, materials of construction and shaft seals.



Getting at the pump discharge pressure may require a few simple calculations. For water, a column 2.31' high is equal to 1 psig of pressure. For materials other than water you would divide by the specific gravity to adjust the column height or what is referred to as the elevation head.



The pressure head is the difference between the point you are pumping from and the point you wish to pump the liquid.



The friction head is the pressure lost due to the resistance of the pump the liquid is being pumped through.



Let's assume we need to pump water to a point 100' higher than an open sump and into a tank with a pressure of 50 psig. The friction loss for this application from pipe tables (call us for a copy of the table) is 15' of head.



The friction and elevation heads total 115' (100'+15') which works out to 49.78 psig (115' / 2.31). The pressure head required on the pump is 50 psig which means the total discharge pressure required from the pump is 99.78 psig (49.78+50).



Grundfos offers a broad range of pumps for liquids up to 2000 centipoises viscosity and temperatures to 350 F. A wide range of options is offered in materials ranging from cast iron through stainless steel and up to titanium to deal with any type of materials.



Grundfos is customer responsive, offers many technical benefits, good on delivery and attractively priced. Next time you need to replace a pump, take a moment to contact us with your application details, or click here to browse all of our Grundfos Pumps Control Specialties offers.