Declutchable Gearboxes Manufacturer & Factory
serving the Czech Republic market

A declutchable gearbox is installed between the pneumatic actuator and the valve. During normal automated operation, the gearbox is disengaged (clutched out), allowing the pneumatic actuator to turn the valve stem directly. When air supply fails or maintenance is required, the operator manually pulls the engagement lever. This meshes the internal worm gear of the gearbox with the valve stem, allowing manual control using the handwheel. Once automated control is restored, the gearbox must be disengaged (clutched in) to allow the actuator to resume control.

Our declutchable override gearboxes comply with ISO 5211, which defines flange dimensions, pilot diameters, and drive square sizes for part-turn actuators. For multi-turn configurations, the gearboxes conform to ISO 5210. Adhering to these international standards makes them compatible with valves and actuators from standard manufacturers worldwide, facilitating integration into European and Czech installations.

To select the appropriate model, you must determine the maximum output torque required by the valve (including a safety margin, typically 30-50% for safety-critical applications). Select a declutchable gearbox whose rated output torque exceeds the valve's torque requirement under differential pressure. Additionally, verify that the input torque needed at the handwheel is low enough for a single operator to turn comfortably, usually keeping manual rim pull forces below 350-400 N.

Yes, we customize our gearboxes for sub-zero environments, which is helpful for outdoor pipelines in northern and central Europe. By using low-temperature cast steels (LCC/LCB), low-viscosity greases, and fluorosilicone seals, we can deliver gearboxes certified for operation down to -45°C or lower. Please specify your local temperature requirements during the RFQ process.

For standard ISO-configured cast steel or ductile iron override gearboxes, we maintain a stock of semi-finished components, allowing assembly, inspection, and dispatch within 2-3 weeks. Transit times from our Suzhou plant to key logistics hubs in the Czech Republic (such as Prague, Brno, or Pilsen) vary between 4-6 weeks via sea freight or 10-15 days via air freight or rail connection.