Definition - What does Tightness Testing mean?
Tightness testing is carried out in pipelines to check the integrity of the pipeline before it is commissioned. Depending on the type of pipeline, the medium for testing may be air, water or oil. Specifications for testing of a pipeline has to be mutually agreed between the contractor and property owner to avoid dispute in case of damage.
Trenchless installation of pipelines are carried out using directional boring techniques and care should be taken that all joints are sealed and pipes are undamaged.
Trenchlesspedia explains Tightness Testing
Tightness testing can be carried out using hydrostatic or pneumatic tests. Hydrostatic tests using water is the preferred method because water is incompressible when compared to inert gas or air. Using air will require more energy to reach the desired pressure, i.e. almost 200 times more energy than that required for water at the same pressure and volume.
A hydrostatic test is carried out by filling the test pipe with water and constantly checking for leaks and the sound of air escaping. Air is released from all high points to ensure that the pipeline is completely filled. Once the pipeline is full, the pressure is raised to the required test pressure and checked for a drop in pressure in the system. If there is no drop in pressure for the specified time, the pipe has passed the tightness test.