Outside- Versus Inside-Mounted Seals, Pump Input Power & Rotodynamic Pump Motor Cooling
Q. What are the advantages of single, outside-mounted seals versus that of single, inside-mounted seals?A. Single seals have one set of sealing surfaces. The lubricant for the seal faces is usually...
HI Pump FAQs is produced by the Hydraulic Institute as a service to pump users, contractors, distributors, reps and OEMs.
Q. Can rotary type pumps be used to pump slurries? If so, should users be aware of any special precautions? A. Rotary pumps may be used to transfer slurries when the application dictates....
Q. What is a regenerative turbine pump? A. Regenerative turbine pumps are characterized by a low flow rate and high head. They use peripheral or side channel vanes or buckets that are manufactured...
Submersible Pump NPSH3, Trench-Type Wet Wells & Starting Torque Requirements
Pumps & Systems, March 2013Q. How do I determine the NPSH3 for a rotodynamic submersible pump?A.  NPSH3 is the net positive suction head required, in meters (feet) that will cause the total...
Q. What are some typical indicators of an inefficient pumping system? A. Many pumping system components are not dynamic. These components allow fluid or heat transfer, but aside from thermal...
Q. How does a liquid’s viscosity affect the performance of rotary sealless pumps? A. The viscosity of a pumped fluid affects the input power and magnetic coupling torque required in a rotary...
Q.What are “nonclog pumps,” and in what applications are they used? Figure 1. Dry pit pump – overhung flexibly coupled vertical end suction A. “Nonclog pumps” are rotodynamic...
Q. What are some differences between specific speed and suction specific speed for a rotodynamic pump? A. The Hydraulic Institute defines specific speed as an index of pump performance (developed...
Q. What are the effects of viscosity on rotary pump and system performance? A. The viscosity of a pumped fluid typically affects pump ratings in the following ways: The net positive inlet...
Q. When selecting wetted pump parts, how much consideration should be given to the temperature of the pumped liquid? A. Handling liquids at temperatures below 32 F (0 C) or above 250 F (120 C)...