Rehabilitation of underground pipes and subterranean confined spaces through a process known as CIPP or "cured in place piping" is quickly gaining momentum around the world. Water, sewer, gas, and chemical pipelines and other subterranean systems with difficult accessibility can now be cleaned and resealed without digging up the entire system. CIPP creates a pipe within a pipe and can be used in a system with as little as a 4 in. diameter. Much larger pipes, over 100 inches, can also be serviced using this method. Little or no digging is required in this environmentally friendly operation. The process involves resin-saturated polyester tube liners being inverted or pulled through a compromised or structurally unsound pipe. This liner can be inverted using water or air pressure. Curing of the resin liner is accomplished using hot water, UV light, or steam and takes from five to 30 hours to cure completely. In the end CIPP forms a tight-fitting, seamless, and corrosion resistant tube within the original pipe. Of course there is quite a bit of confined space entry safety required for this type of operation. Entrants must be carefully trained using gas monitors as well as entry and retrieval devices. And there are several safety standards associated with CIPP including ASTM F1216 which uses test specimens oriented parallel with the pipe axis, as well as the Europe standard EN ISO 11296-4, which tests samples oriented in the hoop direction. At the end of the day, this is a smart technology for many applications and helps utilities and municipalities as well as private projects avoid costly dig and replace methods. If you have questions about CIPP as it relates to confined space entry safety, please give us a ring. If you have experienced any specific challenges installing CIPP yourself, we'd love to hear about it.