Work with Laboratory Ware on Ground Joints

WORK WITH LABORATORY WARE ON GROUND JOINTS 

Ground joints, like glass cocks, must never be used without lubrication/ They are easily damaged if this is done, and the tightness of the connection will be disturbed. Clean the surface of a joint before applying a lubricant to it. Choose the latter depending on the process to be carried out in the ware with joints. 

When working with aggressive gases or volatile liquids, use syrupy substances for lubrication, for instance phosphoric acid or concentrated sulphuric acid. However, owing to its lower viscosity and strong hygroscopicity, the latter is less suitable for this purpose. 

Vaseline oil or glycerin is very often used for lubricating joints and cocks when working with non-aggressive compounds under conditions of room temperature. 

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