glasrör

Glasrör, or glass tube, is a hollow cylindrical piece of glass used to transport and contain liquids and gases and as a component in laboratory glassware. It is produced in a range of sizes and can be cut, bent, or joined to other glass components.

Materials and forms: The most common glass types are soda-lime glass for general use and borosilicate glass for heat and chemical resistance. Quartz glass is used for very high temperatures or high-purity UV applications. Tubes may be straight or curved and may have uniform inner diameter or capillary sizes. Some tubes are designed with ground-glass joints to connect to flasks and other equipment.

Manufacture and properties: Glass tubes are drawn from molten glass and annealed to relieve internal stresses. They are transparent and chemically resistant to many solvents, but brittle and susceptible to thermal shock. End edges may be flame-polished or ground for safe handling.

Usage and care: Typical laboratory roles include reaction and transfer tubes, condensers, drying tubes, and connections between flasks and other equipment. Clean with compatible solvents, rinse thoroughly, and avoid scratching. Store upright in protective sleeves or racks and handle with care to prevent breakage.

Safety and disposal: Broken glass poses cutting hazards; use designated containers for disposal and wear eye protection when handling glassware. Glass tubes may be reused after proper cleaning, or discarded if chipped or cracked.

See also: glassware, laboratory equipment, borosilicate glass.