Zight
Zight
Transparent Gauge Glass - DIN7081
Price: $44.90
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- Category: Flat Gauge Glass
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Made in Tempered Borosilicate, this type of level glass is used in different applications where both chemical resistance and a low thermal expansion coefficient are request-ed. Glasses are manufactured according to the international norm DIN7081, which guarantees quality and reliability.
TRANSPARENT GLASS: TYPE OF LEVEL INDICATION
For transparent level indicators, a two-sided observation system is used; direct observation through the crystals is allowed as the fluid rises or falls. These are mainly used in processes where the color of the liquid is of high importance for the process, or applications which require a protective mica.
TRANSPARENT GLASS: TYPE OF LEVEL INDICATION
| PHYSICAL PROPERTY | TESTING METHOD | VALUE OBTAINED |
|---|---|---|
| THERMAL EXPANSION COEFFICIENT | ISO 7991 | 3.3 x 10-6°K |
| DENSITY AT 25°C | SN 7005 13 | 2.23 g/cm3 |
| REFRACTIVE INDEX (λ = 587.6nm)nd | 1.472 | |
| TRANSFORMATION TEMPERATURE | ISO 7884-8 | 560°C |
| HIGHEST SHORT-TERM WORKING RANGE | ISO 7884-7 | 500°C |
| THERMAL SHOCK RESISTANCE | ISO 7884 | 180 K |
| YOUNGS MODULUS | 63.150 MPa | |
| POISSON CONSTANT | 0.20 | |
| THERMAL CONDUCTIVITY | 20°C - 100°C λ | (1.2)(W·m-1)(K-1) |
| PHOTOELASTIC CONSTANT | DIN 52314 | (4.00 x 10-6)(mm2/N) |
| SPECIFIC ELECTRIC RESISTANCE | DIN 52326 | 250°C |
| DIMENSIONAL TOLERANCES DIAMETER | ± 0.018 | |
| DIMENSIONAL TOLERANCES THICKNESS | ± 0.010 |
TRANSPARENT GLASS: TYPE OF LEVEL INDICATION
| CHEMICAL PROPERTIES | TESTING METHOD | VALUE OBTAINED |
|---|---|---|
| HYDROLITIC RESISTANCE | ISO 719 | HGB 1 |
| ACID RESISTANCE | ISO 1776 | CLASS S1 |
| ALKALINE RESISTANCE | ISO 695 | SLASS A2 |
| CHEMICAL COMPOSITION | SiO2 | Min 80% Content |
| CHEMICAL COMPOSITION | B2O3 | Min 13% Content |
| CHEMICAL COMPOSITION | Na2O + K2O | Min 4.5% Content |
TRANSPARENT GAUGE GLASS: MANUFACTURED IN ACCORDANCE TO DIN 7081
In order to achieve the standardization of this type of type of sigh glasses in all the different industries, the German regulatory institute, DIN for its acronym in German, designed standard parameters for the manufacture of this type of glass.
Among the main characteristics of this regulation are the dimensional parameters, the resistance to pressure, the chemical composition, the characteristics of the reflector prisms, the parameters of tolerances regarding parallelism, and the necessary acceptance tests.
TRANSPARENT GAUGE GLASS: STANDARIZED DIMENSIONS
The level sight glasses, both flat and reflex, have standard measurements dictated by a series of identification. The thickness of the sights is unchanged and remains at 17mm.
The width of the glasses can be either 30mm or 34mm, the latter being the most widely used. The length of the crystals varies based on the identification number, they go from number 1 to number 11. The most common are those mentioned in the table below.
TRANSPARENT GAUGE GLASS: STANDARIZED DIMENSIONS
| THK | RD | LENGTH OF GLASS |
|---|---|---|
| 2 | 3 | 4 |
| 30mm | 15mm | 140 mm |
| 34mm | 17mm | 5-1/2” |
OPERATING TEMPERATURE
The operating temperature should not exceed 280 °C for continuous service.
The glasses that operate constantly between 280 °C and 300 °C must have protective micas, and the total operating service should not exceed 300 hours.
Temperatures over of 280 °C can cause compressive stress on the glass, reducing it to 90% of its initial value for services from 300 hours to 300 ° C.
For resistance to thermal shock, check the operating pressure section. This is because at different pressures and temperatures, the stress on the glass increases and this affects its resistance to thermal shock.
CHEMICAL ATTACK RESISTANCE
In case the glasses are used in boilers, a decrease in mass is likely to occur; this due to the alkaline concentration in the water and its temperature.
The decrease in mass behaves according to the following table, in which the vertical axis represents the loss of mass in mm; the horizontal axis represents the time in ser-vice (in months).
The main attack in loss of mass occurs at temperatures above 200 °C, for this reason, it is a safety requirement to replace the glasses, micas, and gaskets after any disas-sembly, or in accordance with the NORM DIN 7081. Under no circumstances should they be reused.