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Borosilicate glass 3.3 Glass

Borosilicate glass 3.3Glass entirely conforms to the international standard ISO3583,and is a new special borosilicate glass of excellent chemical and physical properties with a silica content of 80%.It is hight stable in structure and,as a result,has marked mechanical strength and very high resistance against chemical attacks,Further,due to ists low linear coefficient of thermal expansion,this glass is capable of withstanding high thermal shock and possesses good moulding abilith,It is an excellent material for making laboratory apparatus where external heating is necessary,intricate laboratory glassware and chemical equipments as well as pressure water meter glass.

Principal Physical and Chemical Properties:

SiO2 Content
>80%
Strain Point
520°C
Annealing Point
560°C
Softening Point
820°C
Refractive Index
1.47
Light Transmission(2mm)
92%
Elastic Modulus
67KNmm-2
Tensile Strength
40-120Nmm-2
Glass Stress Optical Coefficient
3.8*10-6mm2/N
Processing Temperature(104dpas)
1220°C
Linear Coefficient of Expansion(20-300°C)
3.3*10-6K-1
Density(20°C)
2.23gcm-1
Specific Heat
0.9jg-1K-1
Thermal Conductivity
1.2Wm-1K-1
Hydrolytic Resistance(ISO 719)
Grade 1
Acid Resistance(ISO 195)
Grade 1
Alkali Resistance(ISO 695)
Grade 2
Thermal Shock Resistance Rod6*30mm
300°C

Some Directions on Borosilicate glass 3.3

If Borosilicate glass 3.3 Glassware if to be subjected to prolonged heating or pressure,the maximum SAFE operating temperature should not exceed its strain point(520) However,Borosilicate glass 3.3 Glassware is not apt to deform when heated up to its annealing point,and if proper supported and not under high internal pressure,it can be heated up to a temperature of 600 for a relatively short period of time,In such case,the apparatus should be cooled down slowly and uniformly so as to reduce the possibility of strain.

The formula for SAFE operating pressure of Borosilicate glass 3.3 Glass tubes(at 25)p=140t/d(P-SAFE operating pressure(kg/cm);T-thickness of glass tube(mm);D-inner diameter of glass tube(mm).