Challenge
Rotary valves are subjected to severe stresses in industry. Their use is versatile and demanding. For example, rotary valves are used in the chemical and energy industries, in refineries, in district heating systems, in food production and in building automation.
The rotary valves, consisting of an actuator unit, the valve and the control system, require regular maintenance in order to be ready for use at any time. However, disassembly and inspection is associated with high costs and a temporary shutdown of the plant. Due to the conveying of aggressive materials under high pressures and temperatures, wear occurs and the replacement of wear parts must be identified at an early stage.
The throttling element is opened to different degrees during operation in order to regulate the flow. A rotary actuator is used to adjust the throttling element. Mechanical springs and pneumatic pressure on a diaphragm generate the force in the piston. A lever arm converts this piston force into one revolution of the shaft.
The supply pressure of the media flowing through and the torque of the actuator permanently act against each other and lead to wear of the valve. Problems can also occur if the throttling element is blocked, e.g. by hardened polymer melts. Manual pneumatic pressure to open or close the actuator generates previously unknown high torques and can thus, in extreme cases, damage the actuator shaft.
Solution
Inside the drive shaft is the integrated torque sensor coreIN in the direct vicinity of the control choke. This makes it possible to detect the actual loads acting and to use these for monitoring. The built-in temperature sensor measures the temperatures inside the shaft very close to the process and can thus be used to detect overheating of the seal.
Other advantages:
- Wear, sticking or blockages are reliably detected and can be repaired before damage to the shaft occurs
- Commissioning, inspection, maintenance and operation are significantly simplified by the simplified views into the valve interior
Lower maintenance costs due to replacement of wear components as needed - Improved security & documentation capability in a highly regulated environment
