Trenchless Pipelining Tour Los Angeles. Perma-Liner will be on tour with the Trenchless Pipelining Seminar and Demonstration in Los Angeles this Fall. Started in 2008, the Trenchless Pipelining Tour has helped spread the education of our failing underground infrastructure in Los Angeles and everywhere in the U.S. Perma-Liner has taken the Trenchless Pipelining Tour in or around most major cities. If you live or work in Los Angeles, please sign up for the Trenchless Pipelining Tour before it’s full!