Lateral Connection Sealing/Top Hat Installation
Lateral Connection sealing may utilise one of the Localised repair options such as joint sealing or resin injection provided that the lateral can be sealed off at the connection to limit the travel of the sealing materials into the lateral pipeline.
Another option is the use of the Top Hat seal.
A Top Hat seal is a pre-prepared ‘T’ shaped resin impregnated CIPP material that is positioned using a packer mounted on a robotic system or simply an inflatable packer at the site of the lateral connection using CCTV. When pressurised with compressed air the specially designed packer seals against the main pipe wall and extends a bladder into the lateral. The top bar of the ‘T’ sits flat against the main pipe wall whilst the leg of the ‘T’ is inserted into the lateral for a pre-determined length. The resin is then allowed to cure (usually Ambient Cure). Once cured the packer is deflated and withdrawn leaving the Top Hat seal in place. Various Top Hat options are available some of which offer a full main pipeline seal whilst also inserting the lateral connection seal.