SMOKE AND DYE TESTING, MANDREL PULLING, AND MANHOLE VACUUM
Tele-Vac offers several testing procedures
Smoke and Dye Testing
A smoke test moves non-toxic, artificially created smoke through slightly pressurized pipes in order to find leaks. Plumes of smoke form where there are defects. Any sign of smoke escaping can be considered a possible site for leakages.
A mandrel is a device which is pulled through a pipe and used to verify that there is an adequate clearance through the conduit. If, for example, one crushed the conduit during back fill then the mandrel would get stuck.
Manhole Vacuum Testing
This test is performed after placement and compaction of trench back fill and before surface restoration. No testing can begin until the Manhole is clean and ready for testing.
Manhole testing is done by creating a vacuum inside a manhole and monitoring it for vacuum loss. A vacuum loss indicates there is an undesired leak.