This specification covers thermal insulating bricks made from fire clay that are used as backup insulation for refractory furnace linings of boiler furnaces. The bricks shall be composed of heat-resistant materials that have been burned or fired to produce the desired density, strength, and structure. Representative bricks shall be tested, and shall conform accordingly to specified values of bulk density, modulus of rupture, and reheat change.

1.1 This specification covers one type of thermal insulating brick for use as backup insulation for refractory furnace linings of boiler furnaces.

1.2 The values stated in inch-pound units are to be regarded as standard. The SI units in parentheses are for information purposes only and may be approximate.