A coating apparatus for coating a perimeter surface of a pipeline. A frame selectively mounts a sprayer on the pipeline. The sprayer can spray fluid along a flow path in a spraying mode and preparation mode. In the preparation mode, a fluid diverter moves into the flow path to divert the fluid delivered from the sprayer away from the pipeline. In the spraying mode, the fluid diverter moves out of the flow path to permit the sprayer to coat the perimeter surface of the pipeline with a curable liquid. A vacuum system can draw a vacuum through the diverter to remove the fluid the sprayer sprays in the preparation mode. The flow path can be located in a spray shroud. The diverter can fluidly couple the vacuum system to the shroud interior in the spraying mode to remove overspray.