Heat soak test (HST)
The Heat Soak Test (HST) is a test on tempered glass to minimise the risk of the pane spontaneously breaking. Upon request from the customer, Veneto Vetro conducts this test and always recommends it in risky situations to guarantee the long life of its products.
The test involves heating the sheets to 290 °C and maintaining them at that temperature for a certain time, and is conducted to speed up the breakage of the tempered glass panels that would have eventually broken spontaneously. This test enables eliminating more than 99% of the panes that would have broken once installed, due to nickel sulphide (NiS) created by particles of sulphur and nickel that unavoidably end up in the glass mass when the panes are produced in the blast furnaces.
HST is subject to the UNI EN 14179 standard, and it is a mandatory test for the panes that will form buildings’ facades.