[student question] classification and characteristics of pneumatic ball valve?
[answer] pneumatic ball valve can be divided into o-ball valve and v-ball valve. The o-ball valve adopts floating structure, the ball core is precision casting, the outer surface is plated with hard chromium, the valve seat is made of reinforced polytetrafluoroethylene, the port of flow is the same as the pipe diameter, the flow capacity is great, the flow resistance is very small, and there is no leakage when it is closed, it is generally used as on-off valve, especially suitable for high viscosity, v-ball valve adopts fixed structure, the ball core has V-notch, which can realize shearing. Fiber, granular media.
According to different process equipment, pneumatic or electric actuator can be selected to form pneumatic ball valve and electric ball valve respectively. If the pneumatic ball valve is to achieve proportional adjustment, it must be equipped with valve positioner. If the electric ball valve is to achieve proportional adjustment, it must be equipped with electronic electric actuator or servo amplifier.
From the material, it can be divided into: carbon steel ball valve, stainless steel 304 ball valve, 316 ball valve and copper ball valve
According to the pressure, it can be divided into: high pressure ball valve and low pressure ball valve
High pressure pneumatic ball valve: mainly used in oil, natural gas, hydraulic oil, construction machinery and other industries
Low pressure pneumatic ball valve: mainly used in corrosive pipelines such as water! Precautions and model of knife gate valve in use: the opening and closing part of knife gate valve is ram, the movement direction of ram is perpendicular to the fluid direction, manual knife gate valve can only be fully opened and fully closed, and cannot be adjusted and throttled. The ram has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valve form wedge and wedge angle, which vary with the valve parameters, usually 50. The wedge-shaped knife gate valve RAM can be made into a whole, which is called rigid ram. It can also be made into a ram that can produce slight deformation, so as to improve its processability and make up for the deviation of the sealing surface angle in the processing process. This kind of gate When the plate is called elastic ram knife gate valve closed, the sealing surface can only be sealed by the medium pressure, that is to say, the sealing surface of the ram is pressed to the valve seat on the other side by the medium pressure to ensure the sealing of the sealing surface, which is self sealing. Most knife gate valves adopt forced sealing, that is, when the valve is closed, the gate shall be forced against the valve seat by external force to ensure the sealing of the sealing surface. This type of valve shall be installed horizontally in the pipeline generally.
The above contents are sorted out according to the problems encountered in the actual work of the trainees for reference. If there are any problems, please communicate and correct them in time.