Piping and Duct Insulation Types
There are a number of mineral fiber options for insulating mechanical systems, and the product choice depends on the system to be insulated and the desired result.
For installation guidance, refer to the product’s instructions and the manufacturer’s website.
Fiberglass Board and Blanket Insulation
A thermal and acoustical insulation, this product is used for heating and air-conditioning ducts, power and process equipment, boilers and stacks, wall and roof panel systems, tanks, piping, valves, and other systems up to 1000°F (538°C). It is made from inorganic glass fibers preformed into boards bonded by a thermosetting resin, and is produced in a number of densities, thicknesses, and lengths. Jacket options are available: Foil Scrim Kraft (FSK) is a vapour retarder and provides a laminate facing with aluminum foil that helps maximise lighting efficiency; All-Service Jacket (ASJ) is a vapour retarder and provides a laminate facing with a white kraft paper, fiberglass scrim, and aluminum foil.
Fiberglass Commercial Board
Used to insulate round, rectangular, oval, or irregularly-shaped ducts, plenums, chillers, and other equipment, the board is produced at different levels of flexibility/rigidity, and is available with FSK- or ASJ-type facings.
Fiberglass Duct Board
Commonly applied to residential and light commercial HVAC systems that operate at 2” (5 cm) water gauge (wg) static pressure and up to 2,400 feet per minute (fpm) internal velocity, these products are reinforced with aluminum or kraft laminate that acts as an air barrier and water vapour retarder. They are produced in 1” (2.5 cm), 1.5” (3.8 cm), or 2” (5 cm) thick rigid boards, and are made from resin-bonded inorganic glass fibers that stay in place throughout the life of the system.
Fiberglass Duct Liner
Used as a thermal or acoustical insulation, these products are applied to the inside of sheet metal ducts with metal fasteners and adhesives. They are available as blankets or boards with either a coating or a fibrous mat on the surface that is exposed to the airstream, and in a number of densities and thicknesses.
Fiberglass Duct Wrap
A flexible and resilient blanket that can be easily cut and fitted, this product is used to cover sheet metal ducts, including rectangular, round, oval, or irregularly shaped duct surfaces. The wrap is factory-laminated to a vapour retarder facing, and comes in a variety of thicknesses and densities.
Fiberglass Pipe Insulation
For mechanical and process piping, it is produced in 3’ (91 cm) lengths and can be used on systems up to 1000°F (538°C). It is a moulded, heavy density insulation made from inorganic fibers bonded with a thermosetting resin, and is available with or without a jacket.
Rock Wool or Slag Wool Board Insulation
Used to insulate the exterior of process equipment, such as pipes, tanks, towers, oven equipment, industrial furnaces, and vessels. Typically added to high temperature systems, rock wool or slag wool can be used on systems up to 1200°F (649°C). Products are generally available with a facing or jacket, and are produced in a number of lengths and thicknesses.
Rock Wool or Slag Wool Blanket Insulations
Due to their flexibility, these products can be wrapped around pipes, tanks, and vessels, and can be used on systems up to 1200°F (649°C). They are typically applied to cylindrical high temperature duct systems, large piping or groups of pipes, breechings, and flanged fittings. They are generally available with a facing or jacket, and are produced in a number of lengths and thicknesses.
Rock Wool or Slag Wool Pipe Insulations
Used to cover pipes, these products are precision-cut and composed of high density mineral wool that is recommended for applications with piping temperatures ranging from -120°F (12°C) to 1200°F (649°C). They are typically supplied in 36” (91 cm) or 39.4” (100 cm) lengths and a variety of wall thicknesses for pipe sizes from 0.5” (1.27 cm) to 36” (91.1 cm) Iron Pipe Size (IPS). They are available with or without an FSK-type facing.
 Fiberglass insulation can be installed on systems up to 1000°F (538°C) only when High Temperature (HT) Blankets and/or panels are used. The range of temperatures varies depending on the material used (HT Blanket, unfaced board, or FSK board). Typically, unfaced fiberglass commercial boards can be installed on systems operating up to 450°F (232°C) and FSK fiberglass commercial boards can be used up to 250°F (121°C).
 Breechings are ducts through which the prods of combustion are transported from the furnace to the stack, usually applied in steam boilers
 Flanged fittings are items used to change size, direction of flow, level, or assembly of piping, except for unions, grooved couplings, flanges, valves, or strainers boilers