The term "Butterfly Valves" encompasses a number of disk-shaped valves that open and close along an axis that crosses the diameter of the disk. These valves effectively limit the flow of liquids and gasses through pipes that service a number of different types of systems. They also work in automobile engines and in small engines that use carburetors.
History
·         Butterfly valves were used back in 1872 to control the flow of air and steam through fans that were essentially turbines. When using butterfly valves to control the speed of these fans, variable speeds of 1500 to 2000 RPMs (rotations per minute) were possible. In 1893, Carl Benz invented the carburetor butterfly valve which made it possible to vary the running speed of a gasoline engine. Other innovations were made throughout the 20th century.
Butterfly Valve Types
·         A resilient Butterfly Valves has a rubber seat that creates a tight seal around the gate. These valves carry a pressure rating of 232 psi (pounds per square inch). They are good for liquids and gasses. High performance butterfly valves offer many improved design capabilities over resilient butterfly valves, including bi-directional service, direct mount actuation, and high-temperature applications (to 648 degrees Celsius). These valves carry a pressure rating of around 725 psi. Tricentric butterfly valves use metal seats and boast pressure ratings of 1450 psi.
·        Resilient Butterfly Valve
·         Resilient Butterfly Valves are usually designed with a rubber seal that produces a very tight seal. The rubber seals have varying life spans depending on what products they control and the temperature of the products when they are exposed to the seals.
High Performance Butterfly Valve
·         High performance butterfly valves are medium-grade and are smaller than tricentric valves. These valves are used to control water, oil, steam, fuel, and chemical flows for quick, responsive, and tight shut-offs.
Tricentric Butterfly Valve
·         The tricentric butterfly valves are generally the largest and the highest-quality valves on the market. They can be small (3 inches) or very large (60 inches). Manufacturers are capable of producing custom sizes for custom applications.