Liquid Level Gauges and Sight Indicators
Tubular Liquid Level Gauges are designed to view liquid levels using clear or red line Borosilicate tube to observe liquid levels. All valves use a stuffing box configuration to seal the glass tube, and have a ball check shutoff to prevent loss of vessel contents in case of glass failure. Operating pressure and temperatures are subject to the limitations of the tubular gauge glass and washer composition.
Glass tube level gauge is a kind of direct reading liquid level measuring instrument, which is suitable for the spot detection of liquid position in the general liquid storage equipment in the industrial production process. It is simple in structure and accurate in measurement. It is a traditional spot liquid level measuring tool. Generally used for direct detection.
Glass tube:Borosilicate glass,clear or reline.
Protective tube:Stainless steel or bronze
Connections:1/2’’ or 3/4’’ male NPT.
These valve bodies are rated for 500 PSIG at 450F. The actual pressure limitations are of the wall thickness of the glass tube,at the same time the work temperature is the other factors of influence of pressure. These sets are usable with oils and petrochemical liquids. Use with water or steam is not recommended due to the possibility of the steel valves developing rust or corrosion.
The following pressure values are for industry standard high pressure gage glass use. The steam services values are for reference only. For actual steam service, choose stainless steel valves.
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