Pumps are another common type of processing equipment, often literally the “heart” of the system. Typically, the type of pump is chosen based on:
- Fluid Characteristics
- Total Head/Pressure Required
- Desired Flow Rate
- Suction/Lift
The types of pumps shown in the above collage are not the only types of pumps, but the most commonly used in the petrochemical industry:
- Centrifugal Pumps – the best choice for lower viscosity liquids and high flow rates.
- Horizontal Split Case Pumps – one of the least likely pumps to cavitate that features much higher flow rates than end suction pumps.
- Diaphragm Pumps – one of the most versatile choices handling a wide range of liquids that are sealless and can run dry without damage to the pump.
- Progressive Cavity Pumps – sometimes referred to as “the pump of last resort” because it is able to handle difficult liquids that other pumps are unable to accommodate.
- Submersible Pumps – the best choice for areas prone to flooding. Also, these pumps eliminate a column shaft and bearings found in column sump pumps.
- Multistage Pumps – currently, the best way to get high pressure is with a centrifugal pump with lower thrust loads.
- Vertical Turbine Pumps – the best choice for deep wells.
Most often, fluid characteristics determine the type of pump chosen. For instance, the standard centrifugal pump is likely the most common pump used in the industry and has a wide range of compatibility with fluids of different viscosities and makeups. In more difficult applications, such as slurries (fluids with suspended solids), progressive cavity pumps may make more sense.
The pump “curve” is referenced using motor horsepower, inlet/outlet size, etc., to determine the proper pump configuration for the application.
It would be rare for the pump type to affect static equipment design, however, it’s always a good idea to model the entire system to ensure there aren’t physical constraints with the pump that create a need for a specific design consideration with the static equipment (number, type, and location of vessel/tank legs would be a good example here).
Consult with your trusted process engineers, designers, and equipment vendors to help make the best pump selection.
