Borosilicate glass 3.3   contains 80.6% SiO2, 13 % B2O3, 4 % Na2O+K2O and 2,4 % Al2O3. It has a much smaller temperature expansion coefficient (3,3×10-6 K-1) of sodium glass (9 × 10−6 K-1) and is therefore dimensional much more stable and more resistant to cracking due to rapid temperature changes. It is mainly used in the industrial tube, laboratory glassware, kitchenware, optical elements and automotive headlights.

The physical properties of borosilicate glass are available in the PDF enclosure.                

PROMAL Borosilicate Glass Technical Data(pdf)

CATALOG OF STANDARD TUBES DIMENSION                                                                                                      PROMAL Borosilikat 3.3 Tubes Dimension(pdf)

From the PDF catalog you can see the standard dimensions of the pipes with tolerances. Pipes outside of our stock have delivery time within 30 to 90 days, according to the assigned production week at the factory. The minimum order quantity is 1x box (and not 1x tube!).

MATERIAL CERTIFICATE                                                                                                                                                                  Material Certificate(pdf)


Some basic views on the installation of glass pipes in the carrier:

  • the glass tube must not be laden with defelection, lever, shear, bending and the like
  • the construction of the carrier together with the glass tube holders or the level gauge should be sufficient to prevent from accumulating or filling in the tank to mechanically load the glass tube
  • sealing is carried out with O-rings or silicone and rubber seals so as to capture the relatively high tolerance of the glass tubes
  • in addition to mechanical stability, the holders, muffs and other clamping elements should cover the tolerance field of pipe diameter
  • Thicker walls of the level gauge are much more sensitive to temperature shocks and internal stresses, therefore they are basically used only for higher pressure or vacuum, and not for increasing the mechanical and structural strength of the pipe in the carrier