Troughed belt conveyors — Specification ICS 53.040.10 +A1:2010 This is a preview of "BS 8438:2004+A1:2010". Click here to purchase the full version from the ANSI store. ... ISO 3870, Conveyor belts (fabric carcass), with length between pulley centres up to 300 m, for loose bulk materials — Adjustment of take-up device.