Interfit® (150-300mm)

Sealing of lateral connections in relined sewer pipelines is necessary to prevent infiltration, exfiltration and root ingress between the liner and the lateral pipe wall.

Interfit is a resin cured lateral-connection fitting used to seal the gap between the lined pipe and the house service line pipe wall. It is designed to seal approximately 300mm up the junction and therefore beyond the first pipe joint in the house service line. Interfit seals this connection preventing infiltration of groundwater into the sewer, preventing exfiltration of sewerage into the surrounding soil and preventing tree roots from growing into the sewer.

Lateral junction connections come in many sizes, shapes and configurations. Interfit can be used in the widest range of junction configurations; sealing mainline sewer pipelines from 150mm to 750mm diameter and lateral diameters from 100mm to 225mm with lateral angles between 0° and 180°. The patented installation apparatus has been engineered to allow Interfit to be installed in non-standard junctions avoiding expensive and disruptive dig-ups.

Interfit is made of a PVC-coated glass fibre composite felt impregnated with a high performance proprietary silicate resin. The resin has been specifically developed for high bond strength and fast cure. Full cure is reached in as little as 1 hour

The composite resin-felt cures to form a strong long-term bond between the sewer liner and the house service line. Interfit provides a strong, inert, abrasion resistant seal with tested and proven resilience to cleaning and jetting methods.

Installation is non-disruptive and does not require excavation. The Interfit fitting is internally applied by a specially developed inflatable packer which is installed from a nearby access chamber. The packer squeezes the fitting tight against the host pipe while it cures so that there is minimal reduction in cross-sectional area and a smooth transition is formed with the existing pipe. The packer is constructed with a hollow core that allows sewer to keep flowing during installation so that risk of sewerage surcharge is minimised.

Interfit is an essential component for renewing sewer pipelines.