Custom Double Pipe Heat Exchanger Design & Manufacture

Double pipe heat exchangers come into their own when process duties involve low flow rates, large temperature crosses, or extreme pressure differences. Because of their small diameter, they can handle higher pressures with thinner walls than conventional shell and tube units, making them more cost-effective for high-pressure service. They are also the preferred solution for pilot plants and sites where modularity and ease of maintenance are critical.

The challenge with small-scale thermal duties is that a standard shell and tube unit is often over-engineered, bulky, and thermally inefficient for low flow rates. Furthermore, achieving a "temperature cross"—where the cold fluid outlet is hotter than the hot fluid outlet—is physically impossible in many traditional designs.

At Graham Hart Process Technology, we bridge this gap with precision-engineered double pipe solutions. By thermal modelling, we ensure that your unit is optimized for pure counter-current heat transfer. Our "inside-out" mechanical design allows the unit to handle high cyclic temperature variations without the need for expansion bellows, as the inner pipe is free to expand. Whether you are processing high-viscosity fluids in a refinery or managing safety-critical cooling in a nuclear facility, our double pipe exchangers provide a robust, maintainable, and space-saving solution.