Description
DURAN® Kjeldahl flask 500 ml is a specialised laboratory vessel made from borosilicate glass 3.3 for nitrogen determination by the Kjeldahl method. With a nominal volume of 500 ml, the flask is built to endure extreme chemical and physical loads typical of digestion and distillation steps. Body wall thickness is held at 1–2 mm, a deliberate compromise that avoids overly thick walls, which can retain permanent stresses and lead to breakage after overheating, while remaining thick enough to limit progressive glass abrasion in alkaline media. This application-adapted wall design takes technological constraints into account and supports safer, more consistent handling under harsh conditions. Offered as a single piece from manufacturer Duran/DWK Life Sciences, the flask suits analytical chemistry, food and feed testing, environmental laboratories and quality-control workflows that rely on reliable Kjeldahl nitrogen analysis. The DURAN® borosilicate glass 3.3 construction provides the chemical resistance and thermal behaviour required for repeated exposure to concentrated reagents, helping laboratories maintain process integrity throughout demanding sample-preparation sequences.
This article is part of Round-bottom flasks, in Beakers & flasks. See also Flat-bottom flasks.
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Questions about DURAN® Flask, Kjeldahl
What is this article?
DURAN® Flask, Kjeldahl is the article on this page. Luminix Health distributes DWK Life Sciences for laboratory use. It sits in Round-bottom flasks, inside Beakers & flasks, in Labware.
A round-bottom flask is the heating flask of a distillation or a reflux. The curved wall takes the heat, and the ground neck connects to a still head or a condenser. The joint size, not only the volume, has to match the rest of the set.
A beaker is an open working vessel: easy to pour, poor as a measure. An Erlenmeyer flask has a flat base and a conical wall so a liquid can be swirled without climbing out. A round-bottom flask is for heating under a condenser, because the heat meets a curved wall and the joint at the neck connects to the rest of the glassware. Borosilicate is the glass that survives the temperature change. These forms are listed under ISO laboratory glassware.
Which category should I open next?
The category is Beakers & flasks. The sub-category is Round-bottom flasks. The catalogue is Labware.
Shelves beside this one are Beakers, Erlenmeyer flasks, Reaction vessels & jacketed vessels, Flat-bottom flasks, Flasks (other) and Beaker & flask accessories.
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The seven catalogues are Labware, Lab chemicals, Lab instruments, Lab consumables, Chromatography equipment, Lab safety equipment and Life Science & Microbiology.

