Various safeguards are available to prevent catastrophic pump failure.
Every chemical facility uses pumps, which provide the motive force to transfer fluids and slurries from one point to another. Due to their ubiquity in the chemical process industries (CPI), pump safety is an essential topic of discussion. No process is foolproof and incidents happen at every plant. It is our responsibility as chemical engineers to design systems that avoid catastrophic failures should an error occur.
A deadhead scenario occurs when the suction and discharge valves of a pump are closed while the pump is still running. To prevent deadhead, parameters such as energy input, flowrate, power, pressure, and temperature must be closely monitored. Control systems should be designed to prevent prolonged deadhead of pumps, and temperature rise restrictions should be incorporated into pump designs. Control systems must shut down pumps in the event of a deadhead scenario, but operators should also be vigilant and trained to act appropriately during these events. If an operator notices irregularity in the operating pressure, energy input, flowrate, etc., pumping must be immediately stopped. In some instances, pump deadhead has been caused by downstream process equipment (1–4). For example, in a simulated moving bed (SMB) system, the movement of the multiport SMB valve could create a deadhead situation in the pumps that feed the valve.
This article describes the causes of pump explosions and outlines safeguards to avoid deadhead operation and catastrophic loss of containment of pumps. Incident examples highlight the risks of failing to design inherently safe pumps in CPI facilities.
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