(Also known as CIP(P) Lateral Connection Repair, Connection Liner, Cured in Place Repairs (CIPR) for local defects and lateral connection repairs. Sometimes referred to as Top Hats.)
This uses Cured-in-Place (CIP) technology to create a lateral junction liner that is designed to repair, seal and reinforce pipe junctions (such as that between a pipe mainline and a lateral connection).
Often the lining of a lateral/mainline junction is combined with the lining of a portion of the lateral itself. Such connection liners are configured to match the geometry of specific lateral-mainline connections and can be installed remotely via the mainline. To avoid the later displacement of connection liners in service, either the lateral liner is made long enough to lock the connection liner in place or the liner can be formed with a full circular section of liner within the mainline.
When ambient cured resin is used, the resin is mixed and the fabric mat is impregnated just before the material is applied on to the packer. When UV cured resin is used, the carrier and or reinforcing material is already impregnated at the factory with a one component resin ready to apply on the light transparent silicon bladder. For ambient cured material, a protective foil layer is wound around the packer and the fabric mat, which usually comprises two cut and shaped parts, is fitted to the packer. Another protective foil completes the patch and it is secured on the bladder with light windings. The lateral bladder is retracted and flexible packer is then inserted through a manhole into the existing pipe. It can be pulled in place by hand, or placed into position with a remote controlled robot, or winched to the repair position, assisted by a CCTV camera. The packer lateral bladder is then inflated with compressed air to assist the correct location of the lateral. The packer is then fully inflated. The patch then cures tightly against the host pipe and lateral. When fully cured the packer is deflated and removed from the pipe. The CCTV camera is used to confirm the completeness of the repair.
The patch illustrated and described above is based on using an ambient curing resin, which may take in the order of one to two hours to cure. Much faster curing UV resins can be used with a normal curing speed of 7-10 mins with a transparent silicon bladder containing the necessary UV lights.