District heating and cooling pipes are an indispensable part of centralized heating systems, primarily consisting of a medium conveying pipe, insulation layer, and anti-corrosion layer. Galvanized spiral duct insulated pipes are resistant to impact, flame-retardant, possess certain mechanical strength, and are aesthetically pleasing, making them the preferred type of pipe for pipe corridor and outdoor overhead insulation applications. We recommend two spiral duct machines for manufacturing district heating & cooling pipes.