The pipe belt conveyor is a kind of special belt conveyor developed on the basis of the trough belt conveyor. Its working principle is the same as that of the ordinary belt conveyor, which is driven by friction to move the conveyor belt and its materials. Most of the components can be used in common with the ordinary belt conveyor. The difference is that the conveyor belt needs to be rolled into a round tube, so it needs to use a polygon idlers (usually a hexagon idlers) to force the conveyor belt to form a round tube, and continuously transport various loose materials such as powder, granular and block materials in a closed manner. On the basis of continuous research and practice, a set of systematic standards and methods for design, manufacture, installation, commissioning and inspection have been gradually summed up for the circular tube belt conveyor, and a series of them have been formed.