Abstract: Plant is described for cleaning or treating the insides of pipes, tubes and the like. The plant comprises a pipe-receiving station, a cleaning station and means for conveying the pipes, tubes and the like towards and away from the cleaning station in a direction transverse to their axes. The cleaning station includes elongated lance means with spray means at one end and mean for moving the lance means and a pipe, tube or the like axially relative to one another to cause the spray means to traverse the inside of the pipe, tube or the like and spray it with, for example, abrasive material. The inside of the pipe, tube or the like may also be sprayed with treatment liquid or rust-proofing liquid.Two pipes at a time may be treated and the whole plant is preferably so constructed as to be mobile, being constructed of readily assemblable units arranged in a number of standard I.S.O. shipping containers.