Wastewater System Investigation

AED assisted in an installation investigation of (3) self-priming pumps for a refinery’s wastewater recycle pit. The severe vibrations from the pumps were causing intermittent problems with the ultrasonic flow meters leading to a $30k/month temporary workaround, prompting an investigation. AED’s mechanical team reviewed the pump specifications, contacted the manufacturer, and analyzed the installation. The result of the investigation showed the pumps were cavitating due to poor equipment selection, leading to the entrainment of air in the pumps lacking maintained minimum level controls. AED’s solution comprised of a restriction orifice allowing for smoother operation and reduction of pressure build up in the pump. Minimum-level logic was added to the DCS programming to support the new equipment.