Most common valve types and applications
Butterfly valves: Butterfly valves contain a flat disk/flap that swivels sideways to allow, block or regulate flow. These valves are often used in power plants and wastewater plants as shut off or regulating valves. While they are cheaper and smaller than ball valves, they are not good for high-pressure applications.
Check valves: Check Valves allow the flow of media in one direction while preventing flow in the opposite direction. These valves typically have an inlet and an outlet port and operate using differential pressure. They are used to prevent reverse flow — a problematic phenomenon that can occur in piping systems, in which media flows in the wrong direction. This phenomenon can have profound implications such as problematic flow, contamination of the flowing media and damage to the piping system. There are various types of check valves, best suited to different applications.
Plug valves: In plug valves, cylindrical or conical plugs are used to control flow. The plug has a horizontal hole through which the media flows. To open the valve, the plug is rotated sideways to align the hole to the flow. Plug valves can commonly be found in radiators, heaters and air systems.