The main types of butterfly valve actuator are manually operated, motor operated and cylinder operated. The actuator for each functions in a slightly different way to control the movement of the butterfly valve. Learn more below about how to troubleshoot the different types of butterfly valve actuators.
Manually Operated Butterfly Valve
A gear actuator powers this type of valve. It translates motion of handwheels, chain wheels or nuts into quarter-turns of the valve. The valve disc movement is limited by the physical stops placed on the actuator in its housing.
Problems that Arise with a Manually Operated Butterfly Valve Actuator
Actuator damage can occur if the handwheel, chain wheel or nut is forced against the actuator stops. Exerting such force does not result in tighter closure of the valve, and may snap off 1 or more actuator stops. To close the valve more tightly, adjust the actuator itself.
Motor Operated Butterfly Valves
The gear actuators in a motor operated butterfly valve turn the motor input into quarter-turns of the butterfly valve. The valve movement is controlled by limiting switches in the motor itself and by the actuator stops.
Problems Arising With Motor Operated Butterfly Valve Actuators
Ensure the limiting switches are set properly, and avoid excess pressure against the actuator stops to prevent damage to the actuator.
Cylinder Operated Butterfly Valves
Hydraulic butterfly valves use a gear box and a double-acting cylinder to operate the valve movement. Each linear stroke of the double cylinder is converted to a quarter-turn by the gear box. Other auxiliary controls manage the hydraulic power sent to the cylinder, and the operating speed of the cylinder at various settings.
Problems Arising with Cylinder Operated Butterfly Valves
Excess speed and or excess power sent to the valve at any time can damage the actuator, by causing it to jam or to snap off stops.
Unload Butterfly Valves Carefully
Butterfly valve actuators can be damaged during the offloading process. Always move valves with an eye bolt or a rod through their flange holes, rather than wrapping a chain or sling around the entire valve.
Store Butterfly Valves Properly
Always store butterfly valves and actuators indoors, protected from wind, rain, sand and debris. Store the butterfly valve and actuator with the valve disc partially open. Energize the power actuator of cylinder operated butterfly valves when storing them, to prevent contact corrosion from condensation. Keep rubber seats of the butterfly valves out of direct sunlight and out of contact with ozone.
Do not subject the butterfly valve to any stress or flow before the actuator is attached and tested. The clamping device provided with the butterfly valve is a temporary safety measure to prevent damage to the mechanism, and injury to workers while transporting it. The clamp must be removed before the actuator is installed.
Avoid excess input torque levels of beyond 300 foot-pounds on the actuator when using a wrench nut. Do not put more than 200 foot-pounds of torque on the rims of handwheels or chain wheels. Any of these excess torque conditions can break off actuator stops, causing the actuator to fail and the valve to flap uncontrollably.