Hard deposits build inside long, convoluted, small-diameter tubes and frequently require tube replacement. Ultrahigh-pressure waterjets were evaluated as an economical and environmentally friendly means to completely remove coke deposits without detriment to tube walls. A laser-optic surface mapping method was evaluated as a technology that could provide both quantitative measurement of tube inner diameters, with up to 0.001 inch accuracy, and qualitative imaging of the inner tube surface. The cleaning study showed that plain waterjets can controllably remove the subject carbon deposits. While low pressure was effective on lighter deposits, maximum pressure (as high as 55,000 psi) was important for heavy deposits and blockages. It was found that laser-optic data could produce both digital video images and accurate dimensional information. These cleaning and inspection technologies have flexibility for alternate uses, including heat exchanger tubes and process piping.