ZIGHT GLASS FOR RELIABILITY
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.
REFLEX TYPE OF LEVEL INDICATION
Because the glass has reflection prisms, the light spectrum is reflected in such a way that, where there is liquid, the glass color turns opaque and where there is no liquid, it is bright. These are mainly used in the petrochemical industry, oil industry, and general use applications.
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.
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.
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.