Stopcocks The Glassware Gallery Stopcocks Introduction Stopcocks regulate the flow of liquids or low pressure gases just like a kitchen water faucet.
Stopcocks serve many functions in the laboratory and come in many different forms.
Several of the most common types of stopcocks are discussed here. These are the most common types in the laboratory. Some are ground glass with a solid ground glass plug, while others are smooth glass with Teflon plugs. The stopcock can have a straight or oblique bore and even a double oblique bore as shown below. Using your finger, rub the grease evenly around the glass plug and then insert it into the stopcock.