Long borosilicate glass according to and following DIN 7081 | ACI Industriearmaturen GmbH

Long borosilicate glass according to and following DIN 7081

Product specification: Long sight glass panels

Material: Borosilicate glass thermally toughened (hardened)

Removal rates and further information on the glass can be found in our info data sheet and in our brochure.

INFO Data Sheet Round Sight Glass Plates according to and i.A. DIN 7081 – (762.98 KB) MAXOS® Brochure – (662.36 KB)

MAXOS® borosilicate glass safety sight glasses are required wherever visual inspection of processes in containers must be ensured under pressure, thermal and chemical stress.

The high level of safety is achieved by using a special borosilicate glass with good chemical resistance, extraordinary purity and homogeneity. In combination with the low thermal expansion typical of this borosilicate glass, thermal tempering (hardening) leads to a particularly high thermal shock resistance.

Production and quality checks in the process sequence guarantee the property values of the glasses and the close dimensional tolerances. With these outstanding safety properties, MAXOS® safety sight glasses can be used for extreme conditions.

Operating conditions:

The pressure-temperature assignment in the INFO data sheet must be observed! The following table is for orientation purposes only.

Calculation of the pressure resistance: TOOL - Glass consultant borosilicate glass DIN 7081

Operating method: Max. operating 
pressure:
Max. operating 
temperature:
Unprotected reflex and transparent sight glasses 
with saturated steam or hot water pressure
35 bar / 
500 psi
243 °C / 
470 °F
Mica-protected transparent sight glasses 
with saturated steam or hot water pressure
103 bar / 
1500 psi
320 °C / 
608 °F
Reflex sight glasses when used without steam 
and without technically significant glass attack
280 bar / 
4000 psi
38 °C / 
100 °F
For media without technically significant glass 
attack for transparent sight glasses
345 bar / 
5000 psi
38 °C / 
100 °F
High-pressure transparent sight glasses 
in special fittings
414 bar / 
6000 psi
38 °C / 
100 °F

Chemical resistance:

Water resistance DIN ISO 719/720: Hydrolysis class 1

Acid resistance DIN 12116: Acid class 1

Alkali resistance DIN 52332: Alkali class 2

Technical information:

Coefficient of expansion at 20 °C / 300 °C (68 °F / 572 °F) : 4.1 x 10–6 K–¹

Young's modulus: 67 x 103 N/mm²

Thermal conductivity at 90 °C / 194 °F: 1.2 W/(m·K)

Stress-optical coefficient K: 3.2 x 10–6 mm²/N

Thermal shock resistance: 265 °C / 509 °F

Permissible material defects:

Round bubbles enclosed in the glass may have a maximum diameter of 2 mm. Oval bubbles must not exceed the value (length + width)/2 = 2 mm. Pointed bubbles are not permitted.

Permissible bubble frequency

bubble diameter. (d3) Permissible bubble frequency
Permissible bubble frequency
≤ 250 mm > 250 mm
d3 < 0,3 3 pieces per cm² visible surface 3 pieces per cm² visible surface
0,3 ≤ d3 ≤ 0,5 10 pieces per glass 15 pieces per glass
0,5 < d3 ≤ 1 4 pieces per glass 6 pieces per glass
1 < d3 ≤ 2 2 pieces per glass 3 pieces per glass

Dimensional tolerances:

The dimensional tolerances are in accordance with DIN 7081 for borosilicate glass sight glasses. The parallelism is ≤ 0.08 mm for standard sight glasses and ≤ 0.05 mm for high-pressure sight glasses.

Dimensional tolerances according to DIN 7081

Dimensional tolerances for longitudinal glass width 34 mm:

Tolerance
Length (95 ... 400 mm) + 0 mm / – 1,5 mm
Wide (34 mm) + 0,2 mm / – 0,8 mm
Thickness(17,5 mm) + 0 mm / – 1,0 mm

Dimensional tolerances for longitudinal glass width 30 mm:

Length(115 ... 340 mm) Tolerance
up to 250 mm ± 0,8 mm
over 250 mm ± 1,0 mm
Wide (30 mm) + 0,5 mm / – 0,8 mm
Thickness(17,5 mm) + 0 mm / – 1,0 mm
+49 (0) 2461 91634 00
info@aci24.com