MAXOS®

Safety Sight and Level Gauge Glasses

SUPRAX® 8488 Borosilicate glass

The specially developed SUPRAX® 8488 borosilicate glass used for the MAXOS® sight glasses guarantees a superior chemical resistance. The low expansion of the glass combined with thermal prestressing creates a high resistance to sudden temperatures changes.

Technical properties  
Coefficient of expansion α 20 °C/300 °C 4.1 x 10–6K–1  
Max. operating temperature 300 °C 572 °F
Thermal shock resistance as per ISO 718 ΔT 230 °C  
Transformation temperature 545 °C  
Glass temperature for the viscosities dPas (Poise) 1013.0   
107.6     
104.0 
560 °C
800 °C
1,210 °C
1,040 °F
1,472 °F
2,210 °F
Density at 25 °C 2.3 g/cm3  
Modulus of elasticity 67 x 103 N/mm2  
Poisson‘s ratio μ 0.20  
Thermal conductivity λ at 90 °C 1.2 W/(m·K)  
Refractive index nd (λ = 587.6 nm) 1.482  
Photoelastic parameter K 3.2 x 10–6 mm2/N  

SUPRAX® - a registered trademark of SCHOTT AG

It depends on the proportion: The high amount of silicon dioxide (SiO2) and boric acid (B2O3) characterizes this type as a glass former. The proportion of boric acid influences the glass properties in a specific way: We use a proportion of only 11.5 %. This makes it more stable in comparison to glasses with an even higher boric acid content. In addition, the embedding in the structural network ensures extremely high chemical resistance.

The homogeneous distribution of the thermal prestressing ensures increased breaking strength.

Chemical
characteristics
Hydrolytic
resistance
Acid
resistance
Alkali
resistance
Test acc. to DIN ISO 720 DIN ISO 1776 DIN ISO 695
Max. abrasion
acc. to DIN ISO
0.1 <100 μg Na2O/dm2 >75–175 mg/dm2
MAXOS®
max. abrasion
0.050 <60 μg Na2O/dm2 >100 mg/dm2
MAXOS® HGA 1 Class A2

ADDITIONAL INFORMATION