Dropping Funnels (Cylinder) Dropping Funnels (Cylinder) – Laboratory Glassware Equipment Dropping Funnels Cylindrical, open top, with Screw type PTFE Needle Valve Stopcock, Stem with Cone. A dropping funnel is a type of laboratory glassware used to transfer fluids. They are fitted with a stopcock which allows the flow to be controlled. Dropping funnels are useful for adding reagents slowly, i.e. drop-wise. This may be desirable when the quick addition of the reagent may result in side reactions, or if the reaction is too vigorous. Capacity – 50 ml, 100 ml, 250 ml,
