ESP Safety

Several refiners have taken steps to improve ESP safety. These actions include the following  

SIS Safety instrumented shutdown (SIS) systems have been installed on several units. These systems automatically remove feed and hydrocarbon from the process to place the unit in a safe state when a set of conditions that represent an unsafe operation is observed. 

De-energize The ESP is de-energized through automatic controls when the following process situations exist  

SIS trip The ESP is de-energized when the SIS trips and pulls feed. Start-up Start-up conditions represent a risk for upset conditions. The ESP is typically not commissioned until after the unit has reached steady-state. 

However, some refineries are required to operate the ESP whenever the main air blower is energized due to local regulations. These units have subsequently developed procedures to allow the ESP to operate at low voltages to minimize the risk of fire or explosion caused by high-hydrocarbon carryover in the presence of high-oxygen levels. 

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