Category : Trenchless
Trenchless pipe replacement is a permanent solution to tree root growth, aging pipes, and rusted or otherwise failing pipe connectors. This method uses a resin-impregnated, flexible fabric that follows turns in the existing pipe while providing a continuous, sealed, environment from beginning to end. The process to install a new sewer pipe lining is a multi-step procedure that ensures both a superior replacement and that no additional contamination is leaked into the surrounding environment.
One – Clean and Inspect. A plug is placed or a valve is turned off upstream. The existing line is flushed to remove soil and other contamination. Once accomplished, a video camera is inserted and pushed through to determine the extent of the damage, amount of debris, and how much of the existing pipe must be replaced.
Two – Bypass Control. If the inspection cannot be accomplished due to the presence of liquid trapped in the sewer line, the effluent is redirected to another pipe or pumped into the nearest sewer access point.
Three – Clearing Debris. The inspection reveals how much and what type of debris is inside (pieces of the collapse, rocks, plant material, broken connections, etc.). Pieces that cannot be flushed are removed by digging a hole directly above to remove them with as little disturbance to the pipe and surrounding dirt as possible. If an extensive section of the pipe has collapsed, a temporary patch is placed to maintain the integrity of the pipe’s shape so the trenchless line can be inserted.
Four – Excavation or Sliplining. This step is digging the holes for entry and exit of the trenchless pipe material. The locations are determined by the length of the damage, the need to limit disruption to the property, foot or vehicle traffic, and other underground pipes or power lines. Each excavation is accomplished with the idea to insert the material at either point.
Five – Installation. Now that the exact length is determined, the amount of trenchless material is cut and attached to a pulling device. Once in place, an expandable bladder is inserted at the entry point by an air blower. This slowly inflates the material to its full diameter, filling the void. After full expansion, the material hardens to its correct shape. Once it is completely dry or ‘cured’, the new pipe is as hard as PVC and more resistant to tree roots and other types of damage.
Six – Sealing the openings. The new, trenchless pipe is sealed to existing pipe using heat to expand and harden it to the other opening. How far into the undamaged pipe it is sealed depends on the diameter used in the trenchless pipe. Foam sealant is used on the outside of the pipe to hold it in place and then a cement grout is used to seal the entire connection.
Seven – Inspection. Once the pipe and connections have completely cured and dried, a TV camera is sent through to ensure everything has correctly set in-place.
Eight – Reconnect the Sewer Flow. The plug upstream is removed or the valve is reopened slowly. Flow is slowly brought up to 90 percent of the capacity. If needed, additional water is flushed into the system to ensure a proper test is accomplished.
Replacing an existing, broken sewer line with a trenchless lining is an option that involves minor excavation to the surrounding area and precludes the need for breaking up home or business foundations and greatly reduces the amount of manpower needed for the operation. Depending on the replacement length needed, most tasks can be accomplished and service restored in just a day.