Externally Operated Valves are used in many applications, such as: media with high dirt content, media with high viscosity, high ambient temperatures, large flow quantities, damp environments and where there is a risk of explosion. It has very high flow amount. This valve operates from zero differential pressure, high media temperatures and high viscosities. It also operates in EEx areas by placing the pilot valve outside the area. It is also known as air operated angle-seat valves