The bellow control valve is a pneumatically operated process valve with a single-acting diaphragm actuator. A PTFE bellow ensures the separation between medium and actuator. The materials used and the design of the media space allow the use under hygienic or aggressive conditions. It has a good cleanability. The combination with a controller (Type 869x) and the control cone integrated into the bellow enable the valve to handle demanding control tasks. The space-saving actuator with low internal volume not only results in a very compact size but also in remarkably low response times. The valve is characterized by a good control performance due to the low-friction design and has a linear characteristic. A certain variety of body and block system solutions are deliverable.