Physical Properties

physical data

• mean linear and thermal coefficient of expansion α (20°C; 300°C) acc. to ISO 7991

• transformation temperature (Tg

• glass temperature at

• viscosity η in dPa . s

 

• highest short-term admissible working range

• density ρ at 20°C 

• modulus of elasticity E (Young’s modulus)

• Poisson's ratio μ

• thermal conductivity λ  (20°C to 100°C)

• temperature for specific electric resistance 108 Ω.cm (DIN 52326) tklOO

• logarithm of electric bulk resistivity (Ω . cm)

 

• dielectric properties (1 MHz, 25 °C) permitivity ε

• loss factor tan δ

• refractive index (λ = 587,6 nm) nd 

• photoelastic constant (DIN 52314) K

 

 

1013 (upper chilling temperature)

107,6 (softening temperature)

104 (working range)

 

 

 

 

 

 

at 250 °C

at 350 °C

= 3,3 .10-6 K-1

= 525°C

= 560 °C

= 825 °C

= 1.260 °C

= 500°C

= 2,23 g. cm-3

= 64.103 MPa

= 0,20

= 1,2 W.m-1.K-1

= 250 °C

= 8

= 6,5

= 4,6

= 37.10-4

= 1,473

= 4,0.10-6 mm2.N-1

physical data

  • mean linear and thermal coefficient of expansion α (20 °C; 300 °C) according to ISO 7991 = 3,3 .10-6 K-1
  • transformation temperature (Tg)
    = 525 °C
  • glass temperature at 1013 (upper chilling temperature) = 560 °C
  • viscosity η in dPa . s: 
    107,6 (softening temperature) = 825 °C
    104 (working range) = 1,260 °C
  • highest short-term admissible working range = 500 °C
  • density ρ at 20 °C = 2.23 g. cm-3
  • modulus of elasticity E (Young’s modulus) = 64.103 MPa
  • Poisson‘s ratio μ  = 0.20
  • thermal conductivity λ  (20 to 100 °C) = 1.2 W.m-1.K-1
  • temperature for specific electric resistance 108 Ω.cm (DIN 52326) tklOO = 250 °C
  • logarithm of electric bulk resistivity (Ω . cm)
    at 250 °C = 8
    at 350 °C = 6.5
  • dielectric properties (1 MHz, 25 °C) Permitivity ε  = 4.6
  • loss factor tan δ = 37.10-4
  • refractive index (λ = 587.6 nm)
    nd = 1.473
  • photoelastic constant (DIN 52314)
    K = 4.0.10-6 mm2.N-1

tubes and capillaries pressure resistance

Pressure resistance (p) calculation with a known wall thickness (Wt) and a given outside diameter (OD):

p = (Wt x 20 x K/S) : (OD-Wt)


Wall thickness (Wt) calculation with a given pressure resistance (p) and outside diameter (OD):

Wt = (OD x p) : (20 x K/S + p)

 

OD = outside diameter in mm
Wt = wall thickness in mm
p = pressure resistance in bar
K/S = admissible stress in N . mm-2

SIMAX borosilicate glass 3.3 admissible stress: K/S = 7 N . mm-2 according to ČSN EN 1595 Standard: Pressure Vessels Made of Borosilicate Glass 3.3; General Principles for Construction, Manufacturing and Testing.


Pressure resistance (p) affects, among others, the following:

  • thermal difference between the inside and outside walls
  • surface quality
  • working the ends
  • compliance with assembling conditions in accordance with pressure vessels regulations
  • tube length

The manufacturer may perform an exact calculation, where necessary.

 

In addition, the following should be taken into consideration:

  • ČSN EN 1595:1998 Pressure Vessels Made of Borosilicate Glass 3.3 General Principles for Construction, Manufacturing and Testing
  • ČSN EN 12585:1999 Glass Equipment, Pipes and Pipe Fittings. Piping and Pipe Fittings with a NominalDiameter of DN 15 to 1000. Compatibility and Interchangeability