Valve Drive
Drive device: The power part of the belt conveyor consists of a motor high-speed shaft coupling reducer and a low-speed shaft coupling and a brake.
Lined Valve drive device
The valve drive device is a device that uses external power to open and close the valve. The purpose of using a drive device is to make the operation of the valve labor-saving, convenient, quick and reliable, or to achieve automatic control and remote control. The basic requirements for the valve drive device are: the torque or thrust can meet the opening and closing needs of the valve, the control of the stroke and torque is accurate and reliable, the power selection is suitable for the site conditions, the opening and closing action meets the control requirements, and the device itself is light and small.
According to the output shaft movement mode, the valve drive device is divided into three types: multi-turn rotary type, partial rotary type and linear reciprocating type. The multi-turn rotary type is suitable for valves where the valve stem or valve stem nut needs to rotate multiple turns to fully open or fully close, such as gate valves and stop valves. The output torque value series is generally 40~10000 Nm (thrust is 20~1100 kN). The partial rotary type is suitable for valves whose stems can be fully opened or fully closed within one rotation, such as ball valves and butterfly valves. The output torque series is generally 125 to 125,000 Nm. The linear reciprocating type is suitable for valves such as solenoid valves whose stems can be fully opened or fully closed only by linear reciprocating motion. Valve drive devices can be divided into manual devices, pneumatic devices, hydraulic devices, electric devices, gas-liquid linkage devices, electro-hydraulic linkage devices, etc. according to the power source.
The most primitive and simplest valve drive device is the handwheel (handle). With the large-scale valves and the automation of the production process, the demand for various valve drive devices is increasing. Valve drive devices occupy an important position in industrial production automation.
Manual device
The manual device is a deceleration device driven by manpower to reduce the force required for manual operation of the valve. It usually has two types: multi-turn rotary type and partial rotary type. It is characterized by simple structure and easy operation. It is often used to drive valves with a nominal diameter of less than 300mm.
Electric device
A valve electric device uses an electric motor to drive a reduction mechanism to drive a valve. Some valves are driven by electromagnetic force. It has two types: multi-turn rotary and partial rotary. Its characteristics are convenient power supply, easy adjustment, high output, suitable for remote control and automatic control, and widely used. However, when designing and manufacturing, it is necessary to consider the impact of outdoor, flammable and explosive environmental conditions on the electric device, and the structure is relatively complex.
Pneumatic (hydraulic) device
Most pneumatic (hydraulic) devices are composed of pressure cylinders driven by compressed gas or hydraulics, and a few are composed of reduction mechanisms driven by pneumatic motors or hydraulic motors. The former is widely used as partial rotary and linear reciprocating drives; the latter can be used as multi-turn rotary drives, and some can be used with electric devices. They all have the characteristics of compact structure and rapid opening and closing, suitable for indoor or corrosive, flammable and explosive environments; their disadvantage is that the piping is more complicated and not suitable for remote control. The pressure of pneumatic devices is generally (4~6)×105 Pa, and the output is relatively small. Hydraulic devices use higher pressure and have greater output.
Gas-liquid linkage and electro-hydraulic linkage
Gas-liquid linkage and electro-hydraulic linkage are composed of hydraulic mechanisms with compressed gas or electricity as the power source. The most common type is the partial rotary type, which is characterized by rapid action, large output, and can drive large-diameter valves. This device is often used as a shut-off valve or emergency automatic shut-off valve for long-distance oil and natural gas pipelines.
