These requirements cover metallic and nonmetallic chimney liners intended for field-installation into new or existing masonry chimneys that are used for the natural draft venting of Category I gas-fired@ Type L vented oil-fired@ and solid-fuel-fired residential-type appliances in which the maximum continuous flue-gas outlet temperatures do not exceed 1000??(538??. Chimney liners are intended to be installed in existing masonry chimneys with or without a liner of fire-clay tile@ or to be used as a substitute for masonry fire-clay tile flue liners in new chimneys. Chimney liners are intended to be installed in accordance with the Standard for Chimneys@ Fireplaces@ Vents@ and Solid Fuel Burning Appliances@ NFPA 211; National Fuel Gas Code@ NFPA 54 and codes such as the International Building Code@ International Gas Code@ International Mechanical Code@ International Residential Code@ and the Uniform Mechanical Code. Chimney liners as covered by these requirements are not intended for use with Category II@ III@ or IV gas burning appliances as defined by the National Fuel Gas Code@ NFPA 54@ or other appliances that result in condensation of corrosive acids on the liner of the chimney@ or that create positive pressures in the chimney system. Chimney liners with cementitious or refractory flue gas conveying conduits shall be evaluated and marked in accordance with the solid-fuel-fired-appliance sections of these requirements.