Mica shields

Mica shields

Mica shields provides the best protection possible, to flat transparent, sight glasses in water and liquid level gauges and columns in high pressure steam boilers. The shields retain basic strength and increase the service life of sight glasses when used at increased steam pressures and high working temperatures. 

Mica shields also provide perfect visibility for monitoring the nature or degree of combustion in blast furnaces of steam boilers. Sight glasses in steam boilers are exposed to harsh operating conditions (thermal, mechanical and chemical). On the surface of the glass crystallized deposits of mineral substances interact aggressively on the surface of the glass, especially at higher temperatures and pressures, and depending on the pH of the liquid. This interaction not only leads to tarnishing glass, but also the erosion, manifested by decreasing the thickness of the sight glass, which reduces its strength and may lead to dangerous failure. Glass losses for unprotected sight and gauge glasses, depends mainly on the pH and the temperature of the boiler water, could reach millimeters per month (see. fig. below).

Mica shields should be MANDATORY applied where the steam pressure exceeds 40 bar and the temperature exceeds 200 ° C. 

Natural mica has high heat resistance, is transparent; optically clear, flexible, flat and unbreakable. Transparency of mica is unaffected by temperature changes as well as the action of gases and vapors in an environment where it works. In addition, mica is resistant to shock, vibration or deformation and therefore is used as a protection of glass exposed to radiation, mechanical damage and the action of corrosive chemicals.

Typically, mica shields are supplied as complete with gauge glass and seal (here's an example set), but can also be supplied separately. We can also supply plates for non-standard sizes and shapes (see also pages describing Mica windowsand Mica disks in the chapter Our offer/Mica/Natural mica/Mica sheets).

Mica shields provide excellent protection against acids, steam, water, air and oil at high pressure and temperature, and eliminates the risk of cracks, fractures, shock, burning, rinse the glass.

Mica shields are made from the highest quality natural transparent muscovite mica (species Rubby Stained A) and supplied in various lengths, thicknesses and widths according to customer needs.

Mica as a natural mineral, has a layered structure, but you must not separate these layers ! Thanks to the phenomenon of adhesion, naturally created mica layers guarantee its tightness. Any attempt to interfere (delamination) may cause loss of tightness and a significant reduction in the effectiveness of the mica shields.

Before delivery, all mica shields are electronically tested for quality and reliability. They are supplied in individual packages to eliminate scratches and protect them from damage.

Operating and maintenance instructions are enclosed with each package.