Safe use of Glassware
When heated properly, glassware will provide long-lasting and easy service. The following notes will help users get the most life and performance out of their glassware.
Glass may suffer damage in three ways
It may fail under heat stress in the 'steady state'.
It may break when quickly heated or chilled.
Glass, if heated over a particular temperature, may develop a persistent tension upon cooling, failing.
The following suggestions will help in avoiding failures during heating and cooling procedures
Never leave the evaporation vessel unattended. To avoid dryness, reduce the temperature gradually as the liquid level declines; otherwise, the glass vessel may fracture or explode.
When placing a warm vessel on a cold or moist surface, exercise extreme caution. The vessel may break due to sudden temperature changes.
To avoid thermal fracture, cool vessels slowly and gradually.
Heat should never be applied to a badly damaged or etched vase to avoid shattering.
Avoid using a point source of heating in a vessel and instead diffuse it with a metal gauge or air/water bath. Alternatively, guarantee even heating of the vessel by slowly moving it in reference to the heat source.
Some chemical processes require uniform heat. For this, regulate the large soft flame of the Bunsen burner to heat slowly yet uniformly.
To avoid breaking the vessel, adjust the flame contacts and heat it below the liquid level.
When quick heating of the vessel and its contents is required, employ anti-bumping devices such as pumice or glass wool to prevent interior abrasions.
Thick-walled glassware should be heated with an electric immersion heater rather than a direct flame or another localized heat source.
To reduce localized stress and the risk of breakage, do not heat glassware on electric heaters with open elements.
To avoid uneven heating and glassware breakage, always make sure that the hot plate's surface is larger than the base of the vessel being heated.
When utilizing electrical appliances, always adhere to the manufacturer's recommendations.