A Double Pipe Heat Exchanger consists of one pipe placed inside another, allowing two fluids to flow in either the same (co-current) or opposite (counter-current) direction. Heat is transferred between the fluids through the pipe walls. It is simple, durable, and ideal for small-scale or high-pressure applications. https://www.heatexchanger.co.in/Heat-Exchanger/Double-Pipe-Heat-Exchanger/