Metal-seated ball valves are essential components in various industries, providing reliable and efficient control of fluid flow. However, to enhance their functionality and ensure optimal performance, the use of accessories is crucial. These accessories not only improve the valve's efficiency but also extend its lifespan. Valve accessories include driving devices, driving device supporting devices, brackets, connecting shafts and other accessories that connect the driving devices. The drive device of the metal-seated ball valve can be divided into lever handles, steel pipe handles, turbine actuators, handwheel clutch reducers used to switch manual operation or automatic operation, automatic actuators, including pneumatic actuators and electric actuators according to its power source.
One essential accessory for metal-seated ball valves is the actuator. Actuators provide the necessary force to open or close the valve, allowing for precise control over fluid flow. They come in various types such as pneumatic, hydraulic, or electric actuators, each offering unique advantages depending on the application. Another important accessory is the positioner. Positioners accurately position the valve based on input signals from a controller or process variable transmitter. This ensures that the valve operates at specific setpoints and maintains consistent flow control. Additionally, limit switches are commonly used with metal-seated ball valves to provide feedback on valve position. These switches can be used to indicate when a valve is fully open or closed or to trigger alarms when certain conditions are met. Furthermore, stem extensions are often required for valves installed in hard-to-reach areas or underground applications. These extensions allow for easy access and operation of the valve without compromising safety.
For lever handles, steel pipe handles, gear mechanisms and other driving devices that rely on manual operation, calculate the torque according to the working torque value of the product, and then select the appropriate length or specification. Of course, the torsional tensile strength of the material also needs to be considered. The selection of automatic actuators is relatively complicated. Take pneumatic actuators as an example. Pneumatic actuators are divided into single-acting and double-acting types. Double-acting pneumatic actuator has spring force and consistent torque. The single-acting pneumatic actuator must overcome the spring force when opening, and rely on the spring force to close when closing. In this way, its output torque value is a range of torque values, which increases the difficulty of selection. Generally, when installing a pneumatic actuator, it is necessary to multiply by a safety factor to prevent insufficient operating force due to the range change of the actuator output torque based on the working torque value of the valve. Generally, the actual working torque value cannot be measured accurately when it leaves the factory before it reaches the actual working condition. The commonly used standard is to estimate the working torque value based on the no-load torque value multiplied by a dielectric coefficient. For metal-seated ball valves, the medium coefficient should be selected according to different working conditions. If the medium is particle, dust, or mud, the coefficient should be as high as possible, usually within the range of 1.5 to 2.
In addition to the selection of the actuator, the selection of its accessories should also be based on the actual situation, such as related solenoid valves, pressure reducing valves, valve position switches, etc. For example, if a pneumatic actuator has a big air intake and is equipped with a solenoid valve with a small air flow, the air intake of the pneumatic actuator will be very slow; the valve will close slowly, and the sealing surface will be eroded for a longer time, which is not conducive to the service life of the valve. Moreover, the significant advantage of automatic valves lies in their fast opening and closing times. Many customers require that the opening and closing actions be completed within seconds, which puts forward higher requirements for the reasonable setting of related accessories.
In addition to the non-technical failures caused by the above common wrong selection, failures may also occur due to the installation direction and steps not following the specifications during the actual use of metal-seated ball valves. Therefore, during the use of the valve, you should follow the instructions and connect to ensure nothing goes wrong.
One essential accessory for metal-seated ball valves is the actuator. Actuators provide the necessary force to open or close the valve, allowing for precise control over fluid flow. They come in various types such as pneumatic, hydraulic, or electric actuators, each offering unique advantages depending on the application. Another important accessory is the positioner. Positioners accurately position the valve based on input signals from a controller or process variable transmitter. This ensures that the valve operates at specific setpoints and maintains consistent flow control. Additionally, limit switches are commonly used with metal-seated ball valves to provide feedback on valve position. These switches can be used to indicate when a valve is fully open or closed or to trigger alarms when certain conditions are met. Furthermore, stem extensions are often required for valves installed in hard-to-reach areas or underground applications. These extensions allow for easy access and operation of the valve without compromising safety.
For lever handles, steel pipe handles, gear mechanisms and other driving devices that rely on manual operation, calculate the torque according to the working torque value of the product, and then select the appropriate length or specification. Of course, the torsional tensile strength of the material also needs to be considered. The selection of automatic actuators is relatively complicated. Take pneumatic actuators as an example. Pneumatic actuators are divided into single-acting and double-acting types. Double-acting pneumatic actuator has spring force and consistent torque. The single-acting pneumatic actuator must overcome the spring force when opening, and rely on the spring force to close when closing. In this way, its output torque value is a range of torque values, which increases the difficulty of selection. Generally, when installing a pneumatic actuator, it is necessary to multiply by a safety factor to prevent insufficient operating force due to the range change of the actuator output torque based on the working torque value of the valve. Generally, the actual working torque value cannot be measured accurately when it leaves the factory before it reaches the actual working condition. The commonly used standard is to estimate the working torque value based on the no-load torque value multiplied by a dielectric coefficient. For metal-seated ball valves, the medium coefficient should be selected according to different working conditions. If the medium is particle, dust, or mud, the coefficient should be as high as possible, usually within the range of 1.5 to 2.
In addition to the selection of the actuator, the selection of its accessories should also be based on the actual situation, such as related solenoid valves, pressure reducing valves, valve position switches, etc. For example, if a pneumatic actuator has a big air intake and is equipped with a solenoid valve with a small air flow, the air intake of the pneumatic actuator will be very slow; the valve will close slowly, and the sealing surface will be eroded for a longer time, which is not conducive to the service life of the valve. Moreover, the significant advantage of automatic valves lies in their fast opening and closing times. Many customers require that the opening and closing actions be completed within seconds, which puts forward higher requirements for the reasonable setting of related accessories.
In addition to the non-technical failures caused by the above common wrong selection, failures may also occur due to the installation direction and steps not following the specifications during the actual use of metal-seated ball valves. Therefore, during the use of the valve, you should follow the instructions and connect to ensure nothing goes wrong.
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