PYRAN® has been a leading glass for many decades thanks to a groundbreaking combination of borosilicate glass and the float manufacturing process. This results in a range of excellent technical properties, including an ability to withstand large temperature differentials, high viscosity and no NiS crystals.

The ultimate in fire-resistant safety glass

An unrivalled range of temperature resistance

Compared to conventional soda-lime safety glasses, PYRAN® tempered borosilicate glass has a far superior ability to withstand temperature differentials, which means it can be glazed with normal amounts of edge cover (15 ± 2 mm).

Larger panes, easier framing

With a higher softening temperature, PYRAN® is self-supporting for over 30 minutes, which enables the production of very large panes. These panes can be accommodated in relatively basic frame constructions to create a cleaner, more attractive and eye-catching appearance.

Longer fire resistance due to higher viscosity

The high viscosity and durability of borosilicate glass results in low flow behavior, which provides fire resistance times in excess of 90 minutes. The increased amount of edge cover also contributes to this impressive fire resistance.

No NiS crystals mean no sudden fractures

The chemical composition of borosilicate glass prevents the formation of nickel sulphide (NiS) crystals, which can embed within the glass and cause spontaneous fractures. By preventing their formation, PYRAN® offers another source of reassurance and reliability.

Chart showing the specifications of PYRAN® fire-resistant glass


Chart showing the product overview of PYRAN® Star fire-resistant glass


Chart showing the product rating of PYRAN® Star fire-resistant glass

Fire Test

Fire-rated glazing usually requires test certification from an independent and accredited test institute in line with national building codes. The majority of these official tests are carried out according to the standard time-temperature curve, but other temperature scenarios include the hydrocarbon curve, external fire exposure curve and slow heating curve.

Working with our component partners, SCHOTT is able to carry out internal preliminary tests in our own large-scale furnace. This enables us to investigate how the glass and all components behave in test conditions, and provides us with the data required to make any adjustments to the product. These preliminary tests also provide more security when the glass is put forward for its official tests. This saves time and money on repeat tests if they fail, and increases the reputation of SCHOTT products and our partner systems at the test centers.


Engineer in heat-resistant suit conducting a fire test on glass

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Whether you need more information, samples, a quote, or advice for a project, we would be delighted to talk to you.

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Martin Brown, Sales Manager - Technical Glass Solutions
Martin Brown

Sales Manager - Technical Glass Solutions