Mechanical seals are available to repair pipe defects at joints or over short distances along the pipe.
Mechanical seals are used to seal defective pipe joints and other pipe defects. Mechanical seals typically consist of a rubber gasket sized to the dimensions of the pipe and secured by stainless steel retaining rings or cylinders.
Mechanical seal systems come in a wide range of sizes for repair of relatively small diameter pipes to man-entry pipes. Man-entry joint seals are typically positioned and installed manually. Seals used to repair smaller pipes are positioned at the damaged joint or pipe defect either by a remote controlled robot or a winch. The winched–in-place or pushed-in-place system uses an air inflatable packer to expand the seal, pushing the rubber or fabric seal against the walls of the pipe. The seal is secured to the walls of the host pipe either by a ring or cylinder, positioned inside and near the ends of the sleeve. The ring or cylinder is expanded, pressing the sleeve against the walls of the host pipe. Alternatively, the sleeve may be secured by resin between the outside wall of the sleeve and the inside wall of the host pipe, which is cured to create, together with the resin sleeve, a seal that bridges the defect.
Depending on the type of seal and its configuration, the seal may also augment the local structural capability of the pipe, joint or connection.