E-Zine September 2015
Click here to read “Pump Station Control: Introduction”
Click here to read “Pump Station Control: On/Off Control Strategy (Part 1)”
Click here to read “Pump Station Control: On/Off Control Strategy (Part 2)”
Click here to read “Pump Station Control: Modulating Control Strategy (Part 1)”
Click here to read “Pump Station Control: Modulating Control Strategy (Part 2)”
Pumping stations can be purchased as a package system or designed as a custom installation. Some package systems can be provided with either on/off or variable speed drive control strategies. Custom pump stations can be designed using any of the control strategies discussed. The choice of package versus custom pump station controls is often a matter of their economic impact on the process and the ability of the designer to recognize and mitigate these effects.
Package pumping station systems generally do not offer the flexibility of custom designed stations. In addition, many package pumping stations have limited areas for maintenance and limited headroom, making maintenance more problematic. Custom pumping stations are generally built to suit, and the designer often allows the operator more room to work in doing the required maintenance on the station after it has been installed and is operational.
Key design criteria for pumping stations include the ability to handle a wide variation in diurnal flows from minimum through average to peak flow without causing plant upset or flooding the wet well. In addition, designers need to provide a means for equalizing the operating hours, and therefore, the wear on multiple pumps. Designers need to be mindful of both operational issues and maintenance requirements when designing the physical layout of a pump station.
Designing pump station controls correctly can result in years of excellent operation with minimal maintenance. Designing pump controls incorrectly or purchasing a package pump station that does not meet your criteria can swell the cost of operation, increase downtime and maintenance, and result in premature replacement of equipment.
From Flow Control (June 2002)