Resistance to Temperature Gradients
FireLite’s stability in fire is particularly shown by a capability to sustain high temperature differentials that would threaten thermal stress failure of other glazing types – for example, at least three times greater than for modified toughened soda-lime-silica glass, and more than double differentials sustainable by toughened borosilicate.
|Product||Reference Standard||Sustainable Thermal Differential, ℃|
|FireLite||BS EN 1748-2-1:2004||650|
|Toughened borosilicate||BS EN 13024-1:2011||300|
|Toughened soda-lime-silica float||BS EN 12150-1:2000||200|
|Borosilicate (e.g. Pyrex ovenware)||BS EN 1748-1-1:2004||80|
|Soda-lime-silica glass (float glass)||BS EN 572-1:2004||40|
Conventional glass products under thermal stresses are sensitive to edge and surface condition. In normal isotropic glass bodies, surface micro and macro flaws produced during handling and use can act as critical stress concentrators under the severe uncertain and arduous conditions produced by fire.
Toughened (also known as tempered) soda-lime-silica glass, i.e. normal “window” glass composition, can be especially vulnerable to premature failure due to that mechanism.
FireLite is not vulnerable in the same way since significant failure stresses are not generated when it is heated suddenly or to high temperatures - or rapidly cooled from a hot condition.