Level gauge glass MAXOS
Long form reflex and transparent
Bending strength is determined by the surface compressive stress and the
inherent resistance of the glass. the inherent resistance is heavily dependent
upon the surface quality.
For safety reasons, the stress to the glasses caused by internal forces, thermal
stress and vessel pressure have to be totally absorbed by the surface
compressive stress so that a tensile stress of the glass surface is prevented.
Bending strength (typical values)
Standard level gauge glasses
≥ 150 n/mm 2 21,000 psi
Average
170 n/mm 2 25,000 psi
high pressure level gauge glasses
≥ 180 n/mm 2 26,000 psi
Average
200 n/mm 2 29,000 psi
Temperature
thermal shock resistance ∆ t 265 K
Max. permissible temperature 300 °c (572 °f)
protected with mica 320 °c (608 °f)
Surface compressive stress
Standard level gauge glasses
≥ 90 n/mm 2 13,000 psi
Average
100 n/mm 2 14,500 psi
high pressure level gauge glasses
≥ 100 n/mm 2 14,500 psi
Average
110 n/mm 2 16,000 psi
Parallelism
Standard level gauge glasses
≤ 0.08 mm 0.003 inches
high pressure level gauge glasses
≤ 0.05 mm 0.002 inches
