Abstract The inspection of corrosion damage for piping systems both underground and in buildings is required to make repair decisions. It is difficult to inspect and diagnose the outside of underground piping, because the pipe is usually enclosed in casing or in insulation. The emphasis of this research is on internal inspection and corrosion status assessment of gas, water and steam pipes. The prototype designs of the Robotic Corrosion Inspection Crawler were investigated based on kinematic principles. The crawler is designed to negotiate a right angle turn and carry an optical video probe as well as a corrosion inspection probe. The crawler travels inside small diameter pipes and automatically produces a permanent record of the corrosion status for further analysis and decision making. This paper summarizes prototype designs and laboratory testing of the robotic corrosion inspection crawler system.