Single acting pneumatic actuator:

1) It has the function of spring reset and can be selected as normally open or normally closed according to the working conditions. Under ventilation, the pneumatic actuator opens the valve and automatically closes when there is no gas source. Single acting pneumatic actuators rely on springs to automatically reset and are commonly used in dangerous working conditions, such as transporting flammable gases or liquids. In the event of an emergency situation due to the loss of gas source, single acting pneumatic actuators can automatically reset to minimize danger, while double acting pneumatic actuators are generally not easy to reset.

2) Single acting pneumatic actuators are commonly used in dangerous working conditions, and can quickly close or open valves in case of sudden failure due to loss of gas source.

3) In terms of price, single acting pneumatic actuators are more expensive than double acting ones.
 

Double acting pneumatic actuator:

1) It is mainly an air open and air close type, which means that the pneumatic actuator starts to rotate and open the valve when it is ventilated. When the valve needs to be closed, the other side can only be ventilated before it can be closed. It is reset by the cylinder. When the gas source is lost, the valve can only continue to work after the original gas source is reconnected.

2) Generally used in working conditions with low requirements for leakage

3) The price of double acting pneumatic actuators is relatively low.

1. Electrical control

Switching signal: Control the on/off status of valve actuators through electrical switches (such as buttons, relays, etc.).

4-20 mA analog signal: remote control using standard current signal, suitable for precise adjustment of valve position.

2. Digital communication

MODBUS protocol: Through serial communication interfaces such as RS-485 or RS-232, MODBUS protocol is used for data exchange, enabling remote monitoring and control of valves.

CAN bus: Real time communication between multiple devices is achieved through the CAN bus, suitable for complex control systems.

3. Wireless control

Wireless Radio Frequency (RF): Using wireless RF modules for remote control, suitable for places where wiring is inconvenient.

Bluetooth and Wi Fi: Control using Bluetooth or Wi Fi networks, suitable for remote management of homes or small devices.

4. PLC control

Programmable Logic Controller (PLC): The valve actuator is connected to the PLC system, and remote automatic control is achieved through the PLC program, which is widely used in industrial automation.

5. SCADA system

Supervisory Control and Data Acquisition (SCADA): By monitoring and controlling valve actuators through the SCADA system, real-time data feedback is provided for easy management and decision-making.

6. Cloud control

Internet of Things (IoT): Combining cloud computing and IoT technology to achieve remote control and monitoring, users can access and manage valve actuators through mobile devices.

7. Manual and automatic switching

Combination of manual control and automatic control: Some actuators are designed with manual control mode, allowing users to switch between manual and automatic control for flexible operation.

① Use a file to remove the burrs from the valve stem strain; For areas with shallow strains, use a flat shovel to machine them to a depth of about 1mm, and then use sandpaper or angle grinder to roughen them. At this point, a new metal surface will appear.

② Clean the surface with TL-700 metal cleaner to ensure that the repaired surface is free of oil, dust, and dirt.

③ Apply wear-resistant repair agent.

④ Detail trimming.

Preparation and application process of wear-resistant repair agent:

① Prepare repair agent in a volume ratio of 3.8:1;

② Apply the adhesive to the surface of the scratch, with the first coat applied as little as possible, from top to bottom, and no air bubbles are allowed;

③ After the first coat of adhesive is applied for 1 hour (i.e. after the adhesive has preliminarily cured), the repair agent should be re mixed according to the requirements and the second coat should be applied, with a height of 1-2mm higher than the original size;

④ After natural curing for 1 hour, heat with an iodine tungsten lamp at 80-100 ℃ for 3 hours.

Requirements for detailed finishing process:

① Use tools such as files, scrapers, and sandpaper to remove adhesive that is higher than the original size. During the operation, measure it at any time and do not make the adhesive layer lower than the original size. Reserve 0.5mm as the finishing amount;

② When the size reaches the precision level, use a pre processed grinding tool to adjust it (with an 80 mesh sandpaper pad on top);

③ When the size is 0.2mm higher than the original size, replace the diamond sand and grind it to the actual size accuracy.

matters needing attention:

Due to on-site repair, in order to ensure the quality of the repair, it is necessary to clean up the dust, oil stains, etc. around the repair area (especially the upper part); If there are defects (such as small air holes, etc.) after repair, adhesive repair should be carried out, and the operation process is the same as above.

1. Cut off effect

Ball valves can achieve a shut-off function in the process of controlling fluids, that is, the action mode is to rotate the ball 90 degrees, so that the valve channel and the pipeline channel are perpendicular to each other, thereby achieving a closed state. The main principle is based on the design of the ball valve sphere. When the angle is 0, the fluid can pass smoothly, but when the angle is 90 degrees, it cannot pass, thus achieving the purpose of cutting off the fluid.

2. Regulating effect

Ball valves can also achieve regulating effects. In scenarios where flow rate and pressure difference need to be adjusted, the angle of the ball valve can be adjusted to change the cross-sectional area in the channel, thereby changing the size of the fluid passing through the cross-sectional area to achieve regulating effects. The main principle is to change the cross-sectional area of the flow, which decreases with the increase of the angle of the sphere.

3. Cut off effect

Ball valves can also achieve a cutting effect, for example, in emergency situations or when pipeline or equipment needs to be replaced, the purpose of cutting off fluid can be achieved by quickly closing the ball valve. Its main principle is that the opening/closing speed of the ball valve is very fast, which can effectively avoid fluid retention or diffusion.

Therefore, due to the above functions, ball valves mainly have the following uses:

1. As a shut-off and regulating valve in municipal water supply pipelines, gas pipelines, and other systems;

2. As a cut-off, regulating, and shut-off valve in fluid control systems such as chemical, pharmaceutical, and food processing;

3. As a shut-off valve in hybrid control systems for fields such as architecture, metallurgy, and textiles;

4. As a fire extinguishing system