PIPE CONVEYOR BELT

A pipe conveyor belt starts life as an ordinary flat fabric or steel cord belt. After the loading zone it is progressively curled by a series of transition idlers and then enclosed inside a hexagonal cage of six idler rollers that hold it in a closed pipe cross-section for the entire transport length. At the discharge head, a mirror set of transition idlers opens the belt back out, dumps the cargo and returns it (still folded into a pipe on the return strand) to the tail.

Standard pipe diameters range from 100 mm for laboratory installations up to 850 mm for large industrial lifts; belt widths are sized so the carcass forms a fully closed tube with a small overlap (typically 0.35 × π × D of effective width). Because the cargo is completely enclosed, pipe conveyors eliminate dust emission, prevent rain ingress, allow tight horizontal curves (radii as small as 300 × pipe diameter) and let the belt climb to about 30° — somewhat steeper than a comparable troughed belt because the cargo is locked inside the tube and cannot roll back. Typical applications are cement plants, coal-fired power station fuel handling, mineral concentrates and any installation routed over public roads, rivers or environmentally sensitive land.

Engineering trade-offs include higher belt rating (the carcass must be stiff enough to hold the tube shape but flexible enough to flatten at the terminals), more idler rolls per metre (six per pipe set vs three for an open trough), and higher main resistance — often 30–50 % more than an equivalent troughed system, which the [belt capacity calculator](/tools/conveyor-belt-capacity-calculator) accounts for in the Q derate.