4/5” Round Sight Glass
Cobalt Blue Glass
Super thick heat resistant glass,30mm thick,35mm thick,50mm thick,55mm thick,customize thickness
Linkglass can produce super thick sight glass with pressure casting.
30mm thickness heat resistant glass
35mm thickness sight glass.
50mm thickness sight glass
55mm thickness sight glass
More thick sight glass can be customized
Circular sight glass
also named sight glass disc, circular gauge glass, round sight glass, flat plate circular glass discs, etc, commonly it uses the types of materials as below. We suggest different material according to environmental conditions, for instance work temperature, work pressure, acid and alkali of the media.
?soda-lime glass-max work temperature 280 °C
?borosilicate glass- max work temperature 450 °C
?aluminum-silicate glass- max work temperature 650 °C
?glass-ceramic- max work temperature 750 °C
?quartz glass- max work temperature 1100 °C
?sapphire glass- max work temperature 2000 °C
?cobalt blue glass-flame observation
Link glass company based on the skills of adroit professionals and creative workers, we get an extensive range of round sight glass. On account of features like dimensional accuracy, durability and easy installation, our glass is extensively demanded in the market.
Link glass has a team of our adept professionals, with hard-earned experience, designed the offered glass using high advanced technology. Our glass is available to our clients at market leading prices within given span of time.
Food & Beverages,Pesticide Industries,Power Plants,Paint Industries,Glass Industries,Oil Industries
Oil exploration,Gas Industries,Sugar Industries,Cement Plants,Steel Industries,Refineries
Fertilizer Industries,Paper Industries,Chemical Industries,Pharmaceutical Industries
Mining Industries,Copper & Aluminum Industries,Heavy engineering,Automobile Industries
Confectionery,Ship Industries,Nuclear Power Plants
Borosilicate Glass for circular sight glasses or tubular sight glasses
Borosilicate glass is a kind of glass with silica and boron trioxide as the main glass-forming element. Borosilicate glasses become famous for having very low coefficients of thermal expansion, making them more resistant to thermal shock than soda-lime glass. borosilicate glass is fit to be used in sight glass lens,
Borosilicate glass is ultra and clear glass with good thermal and chemical properties and outstanding transparent
Dimensions(mm): 1200×600 ,1150×850 ,1150×1700.(other size upon request)
Available thickness(mm): 1mm-25mm,we also can offer it if you want more thickness.
Density (g/㎝3 ) (at 25℃): 2.23±0.02
Co-efficient of expansion(α)(20-300℃): 3.3±0.1×10-6
Softening point(℃): 820±10
Identical temperature difference(K): 100 >300(Strengthening type)
Maximum working temperature(℃): ≥450
Refractive(nd ) : 1.47384
Light transmission: 92%（thickness≤4mm;91%(thickness≥5mm)
Circular sight glass lens
Tubular borosilicate glass
Appliance glass such as furnace, microwave, gas stove etc.
Industry Glass such as sight glass, linings, etc.
Lighting equipment (protective glass for high-power spotlights and other lamps)
Primary material for fully tempered glass
High temperature stability
Good surface quality
Outstanding transparency in the visible, UV and IR ranges
Can be tempered
High chemical resistance
Environmental engineering and chemical engineering (lining layer of repellence, autoclave of chemical reaction and safety spectacles);
Our circular sight glass is required in all areas where the visual inspection of processes in vessels has to be ensured under pressure, at high temperatures or on exposure to chemicals. These sight glasses is made mainly from borosilicate glass, we also produce sight glass lens with alumino-silicate glass or quartz glass or sapphire glass
Aluminosilicate glass for boiler gauge glass
Alumino-silicate glass is mainly composed of Si-Ca-Al-Mg and other alkali metal oxides through a scientific ratio combination, in which the content of K2O+Na2O ≤0.3%, belongs to the non-alkali aluminum silicate glass system, after high temperature tempering treatment with high temperature resistance, high pressure resistance, acid and alkali resistance and other excellent physical and chemical properties, is a variety of high pressure glass window excellent material.It is mainly used in power plant, petrochemical, nuclear power plant, deep-sea exploration equipment and other kinds of high temperature and high pressure steam package on the high pressure water level gauge glass window.
Color: colorless or slightly yellow
Shape: circular, rectangular
Density: 2.62–2.67 g/cm3
Refractive index: 1.5325 (yellow)
Shock temperature: ≤ 370 °C
Softening temperature: ≥ 920 °C
Bending strength: 240–300 MPa
Max working temperature: 550 °C
round sight glass:diameter:8mm-300mm
Rectangle sight glass:8mm*8mm-300mm*300mm
Linear gauge level glass:Max length 400mm
Quartz glass for round sight gauge glass or tubular sight gauge glass
Normally,quartz glass is fused quartz is the widely usage in industry and home appliances.it is a glass consistant of almost pure silica in amorphous form,it’s purity up to 99.9% according to requirement.
Softening point is 1730℃,long time work temperature 1100℃,short time work temperature 1400℃
Shock thermal:taking out the glass from 1100℃ furnace into 20℃ water,no breakage three times.
The visible light transmittance is more than 93%.
Corrosion resistant:quartz glass can work in the intense acid and alkaline environment
Synthetic Quartz Silica and Infrared Optical Quartz both used as the optical glass.
Property Typical Values
Density 2.2×103 kg/m3
Hardness 5.5 – 6.5 Mohs’ Scale 570 KHN 100
Design Tensile Strength 4.8×107 Pa (N/m2) (7000 psi)
Design Compressive Strength Greater than 1.1 x l09 Pa (160,000 psi)
Bulk Modulus 3.7×1010 Pa (5.3×106 psi)
Rigidity Modulus 3.1×1010 Pa (4.5×106 psi)
Young’s Modulus 72GPa (10.5×106 psi)
Poisson’s Ratio 0.17
Coefficient of Thermal Expansion 5.5×10 -7 cm/cm•°C (20°C-320°C)
Thermal Conductivity 1.4 W/m•°C
Specific Heat 670 J/kg•°C
Softening Point 1683°C
Annealing Point 1215°C
Strain Point 1120 °C
Electrical Resistivity 7×107 ohm cm (350°C)
Dielectric Properties (20°C and 1 MHz)
Sonic Attenuation Less than 11 db/m MHz
Permeability Constants(700°C) (cm3 mm/cm2 sec cm of Hg)
Strength 5×107 V/m
Loss Factor Less than 4×10-4
Dissipation Factor Less than 1×10-4
Index of Refraction 1.4585
Constringence (Nu) 67.56
Velocity of Sound-Shear Wave 3.75×103 m/s
Velocity of Sound/Compression Wave 5.90X103 m/s
Circular sight glass
Tubular sight glass
Ceramic Glass for panel of boiler and fireplace and electric heater
Ceramic Glass has characters: heat resistant, shock temperature resistant, strengthen, hardness, acid-resistant, alkalinity-resistant, low-expansion. transparent ceramic glass, black ceramic glass, bronze ceramic glass, salient point ceramic glass. milk white ceramic glass.
|Bending Strength||180 – 220 MPa|
|Coefficient of Thermal Expansion(-50-600℃)||±8×10-7/℃|
|Softening Temperature||≥ 800℃|
|Work Temperature||≥ 800℃, ≤1000℃|
|Shock Temperature||≥ 700℃|
|Product Density||2.62 – 2.67 g / cm3|
|Process||Grind edge, safety corner, bend|
|Water resistant||ISO719/DIN12111 HGB1|
|Acid resistant||ISO1776/DIN12116 3|
|Alkalinity resistant||IS0695/DIN52322 A2|
Panel of Boiler and Fireplace, Wave Soldering, Oven, Panel of Electric Heater, Protective Panel of Spotlight, Infrared Drying Equipment, Ultraviolet Protection Equipment, Barbecue Plate, Laboratory and High Temperature Welding Mask, Safety Glass.
Sapphire glass for observation window or screen protector
Sapphire glass is now gradually used in pressure observation window, dangerous situation monitoring instrument, deep-water pressure environment instrument and oilfield, coal mine and other occasions.
Our sapphire glass products can be coating treatment, screen printing treatment or special heat treatment according to customer requirements, to adapt to customer’s special needs.
Sapphire window is suitable for ultra high pressure environment.
Compared with tempered glass and other pressure-resistant glass products, sapphire can be thinner under the same pressure environment, effectively reducing the volume of the instrument.
Generally, sapphire can withstand 10MPa of pressure per 5mm thickness.Of course, specific application is still affected by window diameter, use temperature, flange installation.
Our products are used by many petroleum instrument manufacturers in the oil exploitation, drilling industry, product quality is highly recognized.
Shape molding: CNC or laser.
Product thickness range: thickness 0.2-100mm.
Product finish after polishing: 80/50, 60/40, 40/20 (US army standard).
Surface parallelism: less than 20 arc seconds.
Sapphire tube is generally used for high temperature, pressure, corrosion level observation.
Cobalt Blue Glass
Cobalt Blue Glass for observing flame
Cobalt blue glass is used in steel work and cement plant observation scenarios where IR protection is not required, but observation of bright furnaces requires blue eyewear to be able to see into the furnace better.
Cobalt blue glass is NOT a good substitute for green IR glass. Cobalt blue lenses do not protect the eyes from IR radiation like the green IR does, but cobalt blue lenses are not designed for that. Furnace observation cobalt blue glass is designed with the furnace observer in mind, and it allows those who are observing hot furnaces without IR radiation to see into the furnace so they can reduce eye fatigue and increase their vision of the items in the furnace.
The spectrum of cobalt elements makes it incapable of absorbing blue light (i.e., reflecting or passing through blue light, while completely absorbing yellow light with different wavelengths of blue light). Blue cobalt glass filters yellow light because of the presence of cobalt ions.
In observing the flame reaction of potassium needs through cobalt blue glass, because the potassium compounds are not pure, often mixed with some impurities, such as sodium (not easy separation), in the flame reaction, due to the flame yellow sodium, interfere with the flame reaction of potassium (purple), so you have to take yellow light filter, by the light of the principle of complementary color, yellow and blue are complementary colors. Using blue cobalt glass to filter out the yellow light, the potassium’s flame-color, purple, is clearly visible.
Steel plant and cement plant for observing the flame color.
Round or rectangle cobalt blue glass be installed in the observation window.
Cobalt blue glasses.
50mm*50mm; 50mm*100mm; 50mm*107mm,other size can be customized
Cobalt light blue glass be used in laboratory.
Cobalt dark blue glass be used in cement plant and steel works.
Cobalt blue glass component:SiO2:75.01%; B2O3:0.27%; CaO:4.18%; Na2O:15.94%; K2O:1.19%;