Aluminosilicate Gauge Glass

Key Features and Advantages

High Temperature Capability: Suitable for operating temperatures up to 375°C (707°F), depending on pressure, medium, glass dimensions and gauge assembly design.

High Pressure Capability: Aluminosilicate glass is suitable for demanding pressure applications. Maximum allowable pressure depends on glass dimensions, operating temperature, process medium and level gauge construction. Reference aluminosilicate safety glass data indicates pressure capability up to approximately 225 bar under specified conditions.

High Mechanical Strength: Thermally tempered aluminosilicate glass provides high surface compressive strength and improved resistance to mechanical and thermal stresses.

Thermal Shock Resistance: Typical thermal shock resistance is approximately ΔT 230°C according to ISO 718.

Chemical Resistance: Aluminosilicate glass offers good resistance to water, acids and alkalis. For steam, hot water and chemically aggressive media, a mica shield is recommended to protect the glass surface.

DIN 7081-Compatible Dimensions: Available in standard long-form dimensions commonly used in DIN 7081 level gauge assemblies, as well as custom sizes.

Technical Specifications

Parameter	Specification
Material	Thermally Tempered Aluminosilicate Glass
Maximum Operating Temperature	Up to 375°C (707°F)*
Working Pressure	Application-dependent*
Thermal Shock Resistance	ΔT 230°C according to ISO 718
Surface Compressive Stress	≥90 N/mm²
Coefficient of Thermal Expansion (20–300°C)	Approx. 4.8 × 10⁻⁶ K⁻¹
Hydrolytic Resistance	ISO 719, Class 1
Acid Resistance	ISO 12116 / DIN 12116, Class 3
Alkali Resistance	ISO 695, Class 3
Sizes	Standard and custom sizes available

*Actual allowable pressure and temperature depend on glass dimensions, process medium, mica protection, gasket material and the design of the complete level gauge assembly.

Dimensions

Our aluminosilicate gauge glass is available in standard and custom dimensions for industrial level gauge assemblies. Dimensions compatible with common DIN 7081 gauge housings can be supplied according to customer requirements.

Length: Common ranges from 95mm to 420mm (e.g., 95, 115, 140, 165, 190, 220, 250, 280, 320, 340, 370, 400, 420).

Width: Standard widths include 24mm, 30mm, and 34mm.

Thickness: Typically 17mm, 19mm, 21mm, 24mm.

Edge Finish: Available with grind or polish finishes.

Applications

Aluminosilicate gauge glass is suitable for liquid level indication in demanding industrial operating conditions, including:

• High-pressure boilers and steam systems
• Power generation equipment
• Pressure vessels and separators
• Petrochemical and refinery equipment
• Chemical processing equipment
• High-temperature industrial level gauges
• Industrial hot-water systems

For steam, hot water or process media that may chemically attack the glass surface, a suitable mica shield should be used to protect the glass and extend service life.

Frequently Asked Questions (FAQ)

• Q: Does aluminosilicate gauge glass comply with DIN 7081?
• A: DIN 7081 specifically covers pressure-resistant oblong sight glasses made of borosilicate glass. Aluminosilicate gauge glass can be supplied in dimensions compatible with common DIN 7081 level gauge assemblies, as well as in custom sizes.

• Q: What is the maximum operating temperature and pressure?
• A: Aluminosilicate gauge glass can be used in demanding high-temperature and high-pressure applications. Reference data for industrial aluminosilicate safety glass indicates temperatures up to approximately 375°C. Allowable working pressure depends on the glass dimensions, operating temperature, process medium and complete level gauge assembly.

• Q: Can you manufacture custom-sized aluminosilicate gauge glass?
• A: Yes. Standard and custom dimensions are available. We can manufacture aluminosilicate gauge glass according to customer drawings or technical requirements, including custom lengths, thicknesses, edge finishes and markings.