1、 Drive mode
The opening and closing actions of the ball valve are achieved by manually rotating the valve stem. During operation, the operator directly acts on the handwheel or handle, manually rotates the valve stem, and then drives the ball core to rotate, achieving the purpose of controlling fluid flow.
Using compressed air as the power source, the opening and closing of the ball valve are driven by pneumatic actuators. Pneumatic actuators receive pressure signals from the control system, convert pressure energy into mechanical energy, drive the valve stem and ball core to rotate, and achieve fluid control.
2、 Working principle
Manual ball valve: When the valve stem is manually rotated to align the through-hole of the ball core with the pipeline axis, the valve is fully open and fluid can pass smoothly; When the ball core rotates 90 degrees and the through-hole of the ball core is perpendicular to the pipeline axis, the valve is completely closed, preventing fluid from passing through.
Pneumatic ball valve: After the control system sends the valve opening signal, compressed air enters the air inlet of the pneumatic actuator, pushing the piston or diaphragm and other actuating components to move, driving the valve stem and ball core to rotate 90 degrees, achieving valve opening; When receiving the valve closing signal, the actuator exhausts, and under the action of the spring or other reset device, the valve stem and ball core rotate in the opposite direction by 90 degrees, and the valve closes.
3、 Performance characteristics
Manual ball valve operation is simple and flexible: the structure is relatively simple, and manual operation is convenient and fast. Operators can easily control the opening of the valve according to actual needs. Low cost: Due to the absence of complex driving devices such as pneumatic actuators, the manufacturing and procurement costs of manual ball valves are relatively low. High reliability: Without complex pneumatic or electric control systems, it reduces the risk of failure caused by electrical faults or gas source issues, and has high reliability in some simple working conditions.
4、 Pneumatic ball valve quick response:
Pneumatic actuators have fast response capabilities and can complete the opening and closing of valves in a short period of time, making them suitable for situations that require high switching speeds. High degree of automation: It can be integrated with various automation control systems to achieve remote control and automated operations, facilitating centralized management and monitoring. High output torque: Pneumatic actuators can provide a large output torque, suitable for large-diameter ball valves or ball valves used in high-pressure, high viscosity media and other working conditions, and can easily overcome the resistance when the valve is opened and closed.
5、 Applicable scenarios for manual ball valves and low-pressure small-diameter pipelines:
In some low-pressure, small-diameter pipeline systems, such as household water supply and drainage pipelines, small air conditioning system pipelines, etc., manual ball valves can meet simple on-off control requirements, with low cost and easy operation.
Occasions of infrequent operation:
For some occasions that do not require frequent valve operation, such as certain backup pipelines or occasionally used branch pipelines, the simple and reliable characteristics of manual ball valves make them a suitable choice.
Areas with convenient on-site manual control: In areas where operators can easily access valves for on-site manual control, such as local pipeline systems in small factories, equipment pipelines in laboratories, etc., manual ball valves can quickly achieve on/off operations. Automated production process of pneumatic ball valves: Pneumatic ball valves are widely used in the automatic control of fluid conveying pipelines on automated production lines in industries such as petroleum, chemical, pharmaceutical, and food. They can seamlessly integrate with control systems such as PLC and DCS to achieve automation and intelligence in the production process.
In situations where fast switching is highly required, such as emergency shutdown systems, fire protection systems, gas supply systems, etc., pneumatic ball valves can respond quickly to ensure the safe and reliable operation of the system. Adverse environmental conditions: In some harsh environmental conditions such as high temperature, high pressure, flammability, explosiveness, toxicity, etc., pneumatic ball valves can be remotely controlled to avoid direct contact with hazardous environments by operators and improve operational safety.