Managing static electricity during the transfer of flammable liquids is based on the fluid’s conductivity, measured in picosiemens per meter (pS/m). High-conductivity liquids dissipate charge quickly, while low-conductivity liquids (static accumulators) hold onto the charge, creating a spark hazard.
The following table summarizes the maximum flow velocities recommended by NFPA 77 and API 2003 to prevent electrostatic ignition.