Pipe liners are used to prevent leakage or infiltration in pipes and piping systems. There are many different types of products. Traditional pipe liners and pipe lining systems are sleeves, casings, or supports that are inserted along the length of the pipe. By contrast, loose liners are prefabricated products that are dropped into place to form a protective lining system. Films, barrier membranes, coated cloths and tarps are also available. Some pipe liners and pipe lining systems are formed in place through an immersion, spray-on, spray-cast or thermal deposition process. These products are available as liquids, powders, overlay rods, and wires. Other pipe liners consist of tiles, blocks, or sectional elements that are cemented or bonded to a surface and then grouted or sealed. Wear plates or wear strips may also be attached through bonding, brazing, or welding.
Selecting pipe liners and pipe lining systems requires an analysis of specifications such as function and thickness. There are many products that are designed to provide protection against abrasion, corrosion, erosion, electrostatic discharge (ESD), fire, or water. Pipe liners and lining systems with blast mitigation, flow promotion, and friction increasing features are also available. Primary containment systems are high-integrity pipe liners that are designed to contain chemicals or wastes within process pipes for tanks, reactors, bins, and hoppers. Secondary containment products do not have as high a degree of integrity, but provide backup containment. Specialized pipe liners are available for applications such as soil stabilization and sound attenuation.
Pipe liners differ in terms of materials of construction. Choices include basalt, carbide or other hard-metal materials, ceramic materials, composites, fluropolymers, glass, metal, and plastic. Intumescent liners are combustion-modified materials that char to form a protective shield between the flame and the remaining liner and surface underneath. The formed carbon-char has a low thermal conductivity and a high oxidation-resistance. Pipe liners that are made of polyethylene, rubber, or textiles are also available. High-density polyethylene (HDPE) and ultrahigh molecular weight (UHMW) polyethylene provides excellent wear, low friction, and high toughness. Pipe liners and pipe lining systems that are made of textiles provide protection against wear, erosion and other environmental conditions while maintaining flexibility.