Many unlined water mains have internal tuberculation such as that pictured below. Depending on the minerals present in the water, the tubercles can be hard or soft.
How to inspect pipelines that have internal scale and tubercles? There is only one answer: use a Tool that uses RFT (Remote Field Technology). RFT Tools do not require contact with the inner wall of the pipe, and are typically smaller than the nominal bore of the pipe by up to 2" (51.4 mm). This allows RFT Tools to pass through pipelines that have tubercles, or through pipelines that are lined with epoxy, cement mortar, HDPE or FRP, and still achieve accurate measurements of the pipe remaining wall.
For more information on how PICA's RFT Tools can help you to assess the condition of your raw water, treated water, fire water or waste water mains, contact info@picacorp.com