Standard for Lining Systems for Existing Masonry or Factory-Built Chimneys and Vents
1.1 This Standard covers lining systems for existing masonry chimneys,
which may or may not incorporate a liner of fire-clay tile, or factory-built
chimneys and vents.
1.2 Lining systems shall be classed as follows:
Class 1 -- For the venting of gas-fired appliances where the
temperature of the flue-gas products is 135°C or above,
but does not exceed 245°C;
Class 2 -- For the venting of oil and gas-fired appliances where
the temperature of the flue-gas products does not
normally exceed 300°C; and
Class 3 -- For the venting of oil-, gas- and solid fuel-fired
appliances where the temperature of the flue-gas
products does not normally exceed 650°C.
1.3 Lining systems as covered by these requirements, are not intended for
use with Type BH Gas Vents, or with appliances that create positive pressures
within the lining system, or cause condensation of corrosive acids.