The Helical coil encompasses a spiral, comprised of multiple parallel tubes mounted. The coil construction creates a spiral flow path for both the liquid inside and outside of the stainless steel tube coil, providing true counterflow. Tube coil spacing may be vary for optimal balance of thermal and hydraulic requirements. This provides consistent heat transfer efficiency. For unique applications, Lizheng can custom-design tube coils in a wide range of designs, and material, including non-ferrous, stainless steel, titanium, copper.