Sample Process Control Logic Description
Appendix C contains a complete Process Control Logic Description (PCLD) as described in detail in chapter 7.
The following PCLD is for the High Lift Pumping Station at a water treatment plant; this facility discharges treated water out into the water distribution system. This PCLD is based upon a project completed for a water treatment plant and distribution system; the information follows the format as described in Chapter 7.
The high lift station within the water treatment plant receives treated water from the filtration system of the plant. The pumps are started and stopped so as to maintain the level in an elevated water tank between setpoint limits.