How to Size an Actuator for a Ball Valve
How to Size an Actuator for a Ball Valve

How to Size an Actuator for a Ball Valve


Shut-off valves in linear actuators are designed to lock various mechanisms and control the coolant circuits in heating and ventilation systems. Electric valves are among the most popular types of pipeline equipment. With their help, you can block and adjust the flow of liquid or gas as per your requirements, or also eliminate any emergencies. They are widely used in the utility, gas, oil, and agricultural industries, with key benefits including high-speed opening/closing of the stream, reliability, and durability in operation.

The electric drive also provides the ability to work with valves remotely via the control panel. It’s important to know how to choose an automatic valve actuator that’s the proper size for your application. While we here at ActuatorZone do not currently have actuators that are suited towards ball valves, should your actuator have this capability we have outlined how to accurately determine how to choose one.

Ball valve actuator

Electric Valve Actuators - What You Need to Know

As noted above, electric actuator-based valves are used in automation systems as regulators of temperature, pressure, or indirect flow rate of water. In building engineering systems, control valves are widespread with stricter requirements for energy efficiency and increased comfort in the building.

In heating systems, the valve torque controlled by an electric actuator allows you to implement weather-dependent regulation and programmed reduction in heat output after hours. In hot water supply systems, electric control valves are used to maintain a constant temperature of the water heating system, acting as an indirect temperature regulator.

Furthermore, in systems of forced ventilation with air heating or cooling, the heat and cooling performance of the water-air heat exchanger (air heater) is controlled with the help of control valves also.

Electric valve actuator

Form Factor of Ball Valves

Now let's talk about the form factor. Typically, two-way and three-way valves with linear actuators are the most common. The two-way ball valve provides the flow of coolant or refrigerant in one direction and is used to control the temperature and barometric parameters of the working environment. Before the valve, it is recommended to install filters that protect it from clogging and damaging by mechanical impurities.

The three-way ball valve acts as a mixer. Its task is to mix two streams or separate one stream in the right proportions. It is used to equalize the temperature in areas such as heating circuits and hot water networks. In the equipment of supply and exhaust ventilation, this device regulates the heating or cooling of the incoming air.

Thermal engineer repairs a modern heating system in a boiler room

How to Define the Size of your Ball Valve?

Now let's talk about valve actuator sizing. Obviously, before proceeding with the selection of a linear actuator, it is necessary to study the technical characteristics of a ball valve. In particular, you need to take into account:

Break/Running/Sitting Torque

All these parameters determine the force necessary to start, resume, and stop the valve movement.

Maximum Shaft Torque

This parameter determines the maximum force that can be applied to the moving element before it breaks.

Safety Coefficient

Usually, this parameter is equal to 25% however, it may vary somewhat depending on the value of the break torque of the drive.

Throttling Service

This is a valve that controls movement throughout the stroke of a linear actuator. With it, you can increase/decrease speed and completely stop the movement;

On/Off Switch

This switch launches/ceases actuator performance.

All in all, it is important to consider aspects such as the valve form factor, differential pressure indicators, mechanical seal, permissible operating temperature range, and the environmental conditions in which the device will be used. For valves with a complex design (for example, four-way valves), it is impossible to calculate running torque, so it is necessary to measure each valve under different pressure differential conditions.

Conclusion

There are numerous factors to think about before choosing a ball valve for your actuator. We strongly recommend that professionals ask for help in selecting and setting up linear actuators for ball valves. Even if you choose a universal device for domestic needs, this will not be able to guarantee you the correct operation of the entire system. On the other hand, excessive dimensions of the torque actuator can break the valve stem, especially if you have not previously installed safety valves. In turn, the insufficient size of the linear actuator will simply not drive the valve, which is extremely important in systems for emergency shutdown.

For more information on this topic, please feel free to contact us with your query. Thanks for reading!

Anna Sapiga

AZ Engineer