(1)
Insulation and coverings on pipes shall be composed of material suitable for the operating temperature of the system to withstand deterioration from softening, melting, mildew and mould.
(2)
Insulation and coverings on pipes in which the temperature of the fluid exceeds 120°C
(a)
shall be made of noncombustible material, or
(b)
shall not flame, glow, smoulder or smoke when tested in accordance with ASTM C411, “Standard Specification for Hot-Surface Performance of High-Temperature Thermal Insulation,” at the maximum temperature to which such insulation or covering is to be exposed in service.
(3)
Except as provided in Sentence (6), where combustible insulation is used on piping in a horizontal or vertical service space, the insulation and coverings on such pipes shall have a flame-spread rating throughout the material of not more than
(a)
25 in buildings of noncombustible construction, and
(b)
75 in buildings of combustible construction.
(4)
Except as provided in Sentence (6), insulation and coverings on piping located in rooms and spaces other than the service spaces described in Sentence (3) shall have a flame-spread rating not more than that required for the interior finish for the ceiling of the room or space.
(5)
Pipes that are exposed to human contact shall be insulated so that the exposed surface does not exceed 52°C. (See Note A-6.5.1.1.(3))
(6)
No flame-spread rating or smoke developed classification limitations are required where combustible insulation and coverings are used on piping when such piping is
(a)
located within a concealed space in a wall,
(b)
located in a floor slab, or
(c)
enclosed in a noncombustible raceway or conduit.