Definition - What does Flexible Stick mean?
A flexible stick is used to push an inflatable plug into place in pipes to block the flow of material. Whether a trenchless crew is plugging a pipe that has been disconnected in the repair process, or the crew is plugging laterals to isolate the main, the plug is first inserted into the disconnected pipe or the lateral, then inflated. This leaves the lateral in which the plug is inserted isolated from the main or, in the case of a disconnected pipe, it effectively “caps” the end disconnected.
A flexible stick is also known as a drain stick.
Trenchlesspedia explains Flexible Stick
Using the flexible stick to push the plug into place does two things: It helps prevent damage to the inflatable plug because it flexes when it meets resistance, and because the stick is flexible it gives – bends – which allows it to work around bends in the pipe where lateral. Flexible sticks are also used to insert packers, which resemble elongated plugs, into pipes. The packer is used in pipe relining, to minimize the collapse of the liner when inserted into the pipe.