Stopcocks

Stopcocks work as valves, serving to regulate, interrupt, or completely stop gas or liquid flow through piping, tubing, or a faucet, with tubes attached to the stopcock’s female joint, easily separated or connected by a turn of the stopcock. Stopcocks may be held in place by vacuum, rubber rings, or clips. Glass stopcocks need stopcock grease for lubricating and sealing the plug and shell. Glass stopcocks with plastic plugs are sealed without grease but are less effective for high vacuum. Plastic plug glass stopcocks, however, work well for low vacuum applications.