All Pipeline TV & Air Testing, Inc. performs Mandrel Testing, also known as deflection testing, on new pipes ranging in size from 6” up to 18” in diameter. Deflection testing is routinely performed on clean pipes with a mandrel to determine whether or not the pipe has bent under the stress and pressure of the soil above. The mandrel is pulled through a newly constructed sewer line from manhole to manhole. This test is performed to prove the pipe segment has held its integrity or is still round through installation.