Quartz Glass Sheet For High Temperature Boiler Sight Glass

Quartz Glass Sheet For High Temperature Boiler Sight Glass

Category： Quartz Plate
Material:High Purity Fused Quartz
Surface:Polished and clear
Work temperature :1100 degree
Application:High Temperature Boiler Sight Glass
INQUIRY EMAIL

Quartz Glass Sheet For High Temperature Boiler Sight Glass
The high-temperature boiler sight glass quartz plate is a critical component used in observation windows of high-temperature boilers. With excellent high-temperature resistance, transparency, and chemical stability, it ensures operators can safely and clearly observe the internal combustion, reactions, or material status within the boiler.

Performance Parameters
Operating Temperature: Standard quartz glass sight glass can stably operate in environments up to 1000℃.
Thermal Shock Resistance:
With an extremely low thermal expansion coefficient (~5.5×10⁻⁷/℃), it can withstand rapid temperature changes (e.g., from room temperature to 1000℃) without cracking, preventing sight glass breakage due to boiler start-up, shutdown, or temperature fluctuations.
Optical Properties
Visible Light Transmission: Achieves over 90% transmission in the 400nm~700nm wavelength range, ensuring clear visibility of internal boiler conditions for real-time monitoring of combustion efficiency, coking, or material flow.
Infrared/Ultraviolet Transmission: Allows a degree of infrared (>700nm) and ultraviolet (<400nm) transmission, enabling non-contact temperature monitoring with infrared equipment.
Chemical Stability
Corrosion Resistance: Resistant to most high-temperature gases (excluding HF and hot phosphoric acid above 300℃) within the boiler, including SO₂ and NOₓ, maintaining long-term clarity without corrosion or contamination.
Anti-Fouling: Smooth surface and chemically inert, reducing the adhesion of soot, scale, and other impurities, thus lowering cleaning frequency.
Mechanical Strength
Hardness: Mohs hardness of 7, higher than standard glass (Mohs 5-6), providing strong scratch resistance and durability against minor impacts or friction.
Flexural Strength: Approximately 60~80MPa, adequate to withstand internal and external boiler pressure differences (typically ≤0.6MPa) when properly installed with metal flanges.
Specifications
Thickness: Commonly from 3mm to 20mm, selected based on boiler pressure and temperature (higher for high-temperature, high-pressure boilers, such as 10mm to 50mm).
Shape: Usually round (50mm to 300mm diameter) or square (50mm to 200mm side length), customizable to fit specific boiler observation ports.
Edge Treatment: Typically ground or chamfered to prevent stress concentration cracks during installation.

Installation: Used with metal flanges (such as stainless steel flanges) and sealed with high-temperature gaskets (rubber or metal), ensuring airtightness. Some applications use double-layer quartz glass (vacuum or inert gas between layers) for enhanced thermal insulation and safety, preventing outer layer shattering due to large temperature differences.

Cleaning and Maintenance
Surface Cleaning: Wipe with a soft cloth and alcohol or neutral cleaner. Avoid hard brushes or sandpaper to prevent scratches affecting transparency.
High-Temperature Deposits: Allow boiler to cool before gently cleaning with specialized tools to avoid thermal shock damage.
Service Life
Typical Lifespan: 1~3 years under normal use, depending on boiler temperature, frequency of start-stop cycles, and maintenance.
Replacement Indicators: Cracks, localized discoloration (due to high-temperature aging), or significant reduction in transparency necessitate immediate replacement to prevent sudden breakage and ensure safety.
Additional Materials
We also offer high borosilicate glass and tempered glass options to suit your specific requirements.

Material	Long term temperature resistance upper limit	Transmittance	Thermal Shock	Cost	Application
Quartz glass	1200℃	＞90%	Excellent	High Cost	High-temperature, high-pressure, and corrosive environments
Borosilicate glass	500℃	＞85%	Good	Medium Cost	Medium- and low-temperature boilers (e.g., residential hot water boilers)
Tempered glass	300℃	＞85%	Average	Low Cost	Room-temperature, low-pressure equipment