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This is were you can find frequently asked questions about shakingtechnology. You can receive special information about different shaken bioreactors under the respective entry. If you cannot find a solution for your problem, please contact our "Dr. Shaker"-team of experts. |
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| Up to what maximum temperature can borosilicate glass (DURAN®) be used? |
| The maximum permissible operating temperature for DURAN® is +500 °C. Above a temperature of +525 °C the glass begins to soften and above a temperature of +860 °C it changes to the liquid state. |
| What temperature variations can laboratory borosilicate glassware (DURAN®) sustain? |
| As it has a very low coefficient of linear expansion (α = 3.3 • 10–6 K–1) a feature of DURAN® is its high thermal shock resistance up to ΔT = 100 K. |
| What is the lowest temperature to which DURAN® laboratory glassware can be cooled? |
| DURAN® can be cooled down to the maximum possible negative temperature and is thus suitable for use with liquid nitrogen (approx. – 196°C). During such use/ freezing, the effect of the expansion of the content must be borne in mind. In general DURAN products are recommended for use down to – 70 °C. When doing so, bear in mind the product geometry and the properties of any accessories used (e.g. screw caps). When cooling down and thawing ensure that the temperature difference does not exceed 100 K. |
| How chemically resistant is laboratory borosilicate glassware (DURAN®)? |
| Glass is the most universal material in terms of chemical resistance when compared with other materials. DURAN® borosilicate glass 3.3 is highly resistant to water, acids, saline solutions, organic substances and also halogens such as chlorine and bromine. Its resistance to bases is also relatively good. Only hydrofluoric acid, concentrated phosphoric acid and strong bases cause appreciable surface removal of the glass (glass corrosion) at high temperatures (>+100 °C). In detail: Water resistance: DURAN® corresponds to Class 1 of the glasses that are divided into a total of 5 water resistance classes in accordance with ISO 719 (98 °C). Due to its good water resistance, DURAN® meets the requirements of the USP and EP for a neutral glass or corresponds to glass type 1 and can be used in an almost unrestricted way in pharmaceutical applications and in contact with foodstuffs. Acid resistance: DURAN® corresponds to Class 1 of the glasses divided into 4 acid classes in accordance with DIN 12 116. As the surface removal after boiling for 6 hours in normal HCl is less than 0.7 mg/100 cm2, DURAN® is classed as acid-resistant borosilicate glass. Resistance to bases: DURAN® corresponds to Class 2 of the glasses divided into 3 base classes in accordance with DIN ISO 695. Only strong bases combined with high temperatures (>+100 °C) cause appreciable surface removal of the glass. |
| Can DURAN® borosilicate glassware be used in the microwave? |
| DURAN® laboratory glassware is suitable for use in microwaves. This also applies to plastic coated DURAN® products. |
| How accurate are the printed scales on general DURAN® laboratory glassware items? (Beakers, Erlenmeyer flasks, laboratory bottles) |
| For DURAN® beakers, Erlenmeyer flasks, laboratory bottles, etc., a scale accuracy of ± 10% is attained for the bottom and top scale markings. I.e. the products are not suitable for use as volumetric glassware. |
| Are DURAN® products suitable for working under pressure and vacuum? |
| Only the extra designated products are, due to geometry and wall thickness, suitable for working under pressure/vacuum (e.g. filtering flasks, desiccators or flat flange vessels). |
