An electric heater for industrial liquids comprises a plastic flat box that contains a stainless steel pressure vessel holding a number of parallel electrical heating rods. These heating rods are interlaced with shorter "I" shaped Teflon rods which generates a tube-like space around the heating rods. Spiral grooves in the symmetrical concave faces of the Teflon rods promote a spiraling turbulent flow. The general liquid flow from the liquid inlet meanders around the parallel heating rods for optimal heat transfer. The heater can be mounted horizontally or vertically on the side of a lab bench or a vessel for floor space conservation. The flow speed of the liquid, its specific heat, the number of heating elements with their individual power rating determine the heating profile of liquid temperature versus cumulative length of the flow path which is important to prevent the liquid from reaching the boiling point. This arrangement allows for design flexibility and scalability in heating capacities. The pressure vessel, the wet space, has a smooth interior layout for easy Teflon spray coating to make it suitable for heating aggressive etching liquids.