Working with pressure/vacuum conditions in the lab is common but not all products are designed to withstand this. Products with appropriate geometry and wall thickness are suitable for working safely with pressure. For example, filtering flasks, desiccators, or flat flange vessels, as well as products like the DURAN® pressure plus+ range of bottles. These provide guaranteed vacuum and pressure resistance from –1 bar to + 1.5 bar due to modified geometry and a greater wall thickness than standard DURAN® borosilicate 3.3 laboratory bottles.
When used under positive or negative pressure, and especially when also working with differential temperatures, additional care measures must also be taken. Glass apparatus that are under pressure/vacuum should only be subject to further stress, such as significant temperature changes, with extreme caution, as this added strain could result in failure.
Points to consider
Here are some points to keep in mind when working with pressure in the lab to keep the user safe:
- To avoid stresses on the glass, the vessel should be heated evenly, not on one side or heated with an open flame.
- The maximum figures indicated in the product specification should not be exceeded.
- Visually inspect the glassware before using it under vacuum. The glassware should not have any serious scratches, micro-cracks or abrasions. Damaged glassware should not be used under pressure/vacuum for safety reasons.
- Never subject glassware to sudden pressure changes, the pressure should be changed slowly to avoid breaking the glasssware.
- Lab glassware with a flat bottom (e.g Erlenmeyer and flat bottom flasks) should not be used under pressure/vacuum.
- Plastic coating of lab bottles have no influence on pressure resistance. These products are not designed for use under pressure, only the Duran Pressure plus bottles should be used.
