Typical electrocoalescers are large settling tanks containing electrodes and operates under laminar-flow conditions with bare electrodes that may be vulnerable to short circuiting. An alternative to this type of coalescer is a flow through pre-coalescer that is installed upstream in a separator tank. In the Compact Electrostatic Coalescer. droplet coalescence is achieved by applying AC electric fields (50–60 Hz) to water-in-oil emulsions under turbulent-flow conditions. The turbulence increases the collision frequency between the water drops. The electrodes are insulated to prevent short circuiting, and permits water contents of up to 40% as well as water slugs. The equipment is a separate flow-through electrostatic treatment section installed upstream of a gravity separator to improve the performance. By keeping the treatment and settling sections separate, a compact electrostatic coalescer can be obtained that can also be retrofitted.