Tensioning Belts on Installation

At minimum driving tension little elastic or permanent stretch occurs in Biscor glass, Kevlar® or Nomex® belts, but tensioning devices should allow for up to 1% of belt length (dependant on belt length).

On longer belts at high temperature thermal expansion may need to be considered. Where conveyor structure does not stand independent of the oven, variation of end pulley centre distance occurs with temperature and this may be sufficient to call for constant tension devices (spring, gravity, or pneumatically operated).

Such devices are a desirable feature in any case, but it is essential to ensure that the pulley in contact with the belt remains parallel to its original position when moving. (To assist belt installation a tensioning device with, say 250mm half distance travel would be useful. Sufficient slack for belt installation can be obtained by having an accessible, removable pulley in the belt circuit.