Georg Fischer Type 578 Butterfly Valve

The Georg Fischer Type 578 Butterfly Valve has several beneficial design features unique to the Georg Fischer butterfly valve line. The double eccentric operating principle has an off-center disc and shaft that disengages the disk from the seal with only 3 degrees of rotation. This significantly reduces component wear and required operating torque, as the disk is not in contact with the seal when the valve is opening and closing. Conversely, a traditional boot-style valve has a centric design, significantly increasing the required operating torque because of the disk sealing principle associated with these valves. Boot-style valves often show a far more dramatic increase in required operating toque over time than a double eccentric valve. This can result in premature actuator failure and can even render the valve inoperable. Georg Fischer double eccentric butterfly valves require approximately 50% less operating torque than boot-style competitive valves.

The 578 valve also features a truly non-wetted shaft design. The bushing assembly has a double O-ring seal on both the disk and body sides, providing the highest level of protection and reliability.