1.1 This specification covers the composition, dimensions, and physical properties of compression-resistant, perpendicularly oriented mineral fiber (rock, slag, or glass) roll and sheet insulation intended for use on flat, curved, or round surfaces operating at temperatures between 0°F (–18°C) and 1000°F (538°C). This product (pipe and tank insulation) is typically used on nominal 24 in. (610 mm) or greater diameter surfaces. For specific applications, the actual use temperatures and diameters shall be agreed upon between the manufacturer and the purchaser.1.2 The orientation of the fibers within the roll or sheet insulation is essentially perpendicular to the heated/cooled surface (parallel to heat flow). This specification does not apply to flat block, board, duct wrap, or preformed pipe mineral fiber insulation where the insulation fiber orientation is generally parallel to the heated/cooled surface (across the heat flow).1.3 For satisfactory performance, properly installed protect