Boiler tempered glass, also known as boiler sight glass or boiler observation window glass, is a special safety glass specially designed to adapt to high temperature, high pressure, and alternating cold and hot working conditions of boilers. It is mainly used for boiler water level gauges, observation holes, and equipment observation windows, and is a core accessory for boiler operation monitoring and safety duty. Compared to ordinary tempered glass, boiler specific tempered glass has stronger resistance to high temperature, high pressure, thermal shock, and explosion, and is widely used in industrial steam boilers, hot water boilers, heat transfer oil furnaces, waste heat boilers, and other thermal equipment.
一、 The selection of two mainstream materials is crucial
The tempered glass for boilers on the market is mainly divided into two types: ordinary sodium calcium tempered glass and tempered borosilicate glass. Mixing is strictly prohibited for different working conditions.
1. Ordinary sodium calcium tempered glass
Suitable for low temperature and normal pressure working conditions, long-term temperature resistance ≤ 250 ℃, moderate heat shock resistance, and easy cracking due to sudden changes in temperature. It is only used as an auxiliary observation port for atmospheric hot water boilers and low-temperature equipment, and cannot be used for steam boiler water level gauges and high-pressure fire observation positions. There is a risk of self explosion and explosion.
2 ，Tempered borosilicate glass (standard for industrial boilers)
At present, industrial steam boilers are generally preferred. High temperature resistance, good thermal stability, low coefficient of thermal expansion, long-term use up to 300 ℃, excellent resistance to thermal shock, conventional thickness can withstand medium and high pressure conditions, resistant to steam corrosion, and not easy to explode. Clear light transmission, precise observation, in line with industry standards, far safer and more stable than ordinary tempered glass, suitable for long-term continuous operation of the vast majority of industrial boilers and pressure boilers.
二 、 Common types and uses
1. Circular fire observation glass
Installed on the furnace door and barrel observation port, it is used to observe the combustion, ash accumulation, and coking of furnace flames, facilitate the adjustment of combustion conditions, and ensure stable and efficient boiler combustion.
2. Glass for long strip water level gauge
Boiler water level dedicated, divided into transparent and reflective types. Transparent and dirt resistant, with clear and intuitive steam water boundaries and readings, it is used for real-time monitoring of boiler water level, effectively preventing safety accidents such as water shortage and full water, and is a key observation component for safe operation of boilers.
三， Key points for installation and use
Many glass explosions are not quality issues, but rather caused by improper installation and use. High temperature resistant graphite pads and mica pads must be used for buffering during installation, and direct hard contact between glass and metal is strictly prohibited; Tighten the bolts diagonally and evenly to avoid cracking due to one-sided compression. Tempered glass cannot be cut, polished, or drilled again, as it can easily damage the stress structure and cause cracking. Try to avoid rapid heating and cooling during use, reduce thermal shock, regularly clean scale and oil stains, inspect cracks, and replace aging glass in a timely manner to ensure equipment safety.
四、 Summary
Although tempered glass is small, it is the "safety eye" of boilers. Ordinary tempered glass can be used for low-temperature and atmospheric pressure equipment, and tempered borosilicate glass must be used for all steam boilers and high-pressure and high-temperature conditions. Proper selection, standardized installation, and regular maintenance can not only significantly reduce the risk of explosion and extend the service life, but also ensure the stable, safe, and compliant operation of the boiler from the details.
