Classification and Characteristics of Pneumatic Ball Valve

Overview: As the name suggests, the pneumatic ball valve is a ball valve equipped with a pneumatic actuator. The pneumatic actuator performs relatively fast, and the fastest switching speed is 0.05 seconds / time, so it is usually also called the pneumatic quick cut-off ball valve. Pneumatic ball valve is usually configured with various accessories, such as solenoid valve, valve processing, triple, limit switch, positioning, control box, etc., in order to achieve in-situ control and remote centralized control, in the control room can control the valve switch, do not need to run to the scene or high and dangerous manual control, to a large extent save the human resources and time and safety.

Classification: The Pneumatic Control Ball Valve can be divided by structural form:

一、Floating pneumatic ball valve: the sphere of the pneumatic ball valve is floating, under the action of the medium pressure, the sphere can produce a certain displacement and press on the sealing surface of the exit end, to ensure that the outlet end sealing. The structure of the floating pneumatic ball valve is simple and has good sealing, but the load of the sphere under the working medium is all passed to the outlet sealing ring, so it should consider whether the sealing ring material can withstand the working load of the sphere medium. This structure is widely used in medium and low pressure ball valves.

二、Fixed ball pneumatic ball valve: The sphere of the pneumatic ball valve is fixed and does not move after pressure. The fixed ball valve is equipped with floating valve seats. After receiving the medium pressure, the valve seat moves to press the seal ring to the sphere to ensure the sealing. Usually installed in the upper and lower shaft bearing, operating a small torque, suitable for high pressure and large caliber valves. In order to reduce the operating torque of the pneumatic ball valve and increase the reliability of the sealing, the oil sealing ball valve has appeared in recent years, injecting special lubricating oil between the sealing surface to form a layer of oil film, which enhances the sealing, and reduces the operating torque, more suitable for high pressure and large caliber ball valve. 

三、Elastic ball pneumatic ball valve: The sphere of the pneumatic ball valve is elastic. The ball and the valve seat sealing ring are made of metal material, the sealing specific pressure is very large, relying on the pressure of the medium itself has not reached the requirements of sealing, the external force must be applied. This valve is suitable for high temperature and high pressure media. An elastic sphere opens an elastic groove at the lower end of the inner wall of the sphere and obtains elasticity. When closing the channel, use the wedge head of the stem to open the sphere with the seat pressure to reach the seal. Release the wedge head before turning the sphere, and the sphere returns to its original shape, causing a small gap between the sphere and the valve seat, which reduces the friction and operating torque of the sealing surface.

Pneumatic ball valve can be divided into straight, three and straight angle. The latter two ball valves are used to distribute the medium and change the flow direction of the medium.

Classification and characteristics: pneumatic ball valve has O-ball valve and V-ball valve. O ball valve using floating structure, ball core for precision casting, exterior hard chrome treatment, seat using enhanced PTFE material, flow crossing and pipe of the same diameter, great circulation capacity, small flow resistance, no leakage, generally do switch valve, especially suitable for high viscosity, V ball valve using fixed structure, ball core open V incision, can realize shear containing fiber, granular medium. According to the different process equipment, can choose pneumatic or electric actuator, respectively form the pneumatic ball valve and electric ball valve, if the pneumatic ball valve must be equipped with valve positioning device, electric ball valve to achieve proportional adjustment must choose electric 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, 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, engineering machinery and other industries; low pressure pneumatic ball valve: mainly used in the medium for water and other corrosive pipelines. Notes in the use of knife type gate valve products: the opening and closing part of the knife type type gate valve is the gate plate, the direction of motion of the gate plate is perpendicular to the fluid direction, the manual knife type gate valve can only be fully opened and closed, not for adjustment and throttling. The gate has two sealing surfaces, the most commonly used mode of gate valve form wedge, wedge Angle varies with the valve parameters, usually 50, the wedge type gate valve gate can be made into a whole, called rigid gate; it can also be made to improve its process, to compensate for the deviation of the sealing surface Angle in the processing process. This gate is called elastic gate. When the knife-type gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, the medium pressure presses the gate sealing surface to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most of the knife gate valve is using forced sealing, that is, when the valve is closed, to rely on external force to force the gate plate to the valve seat, in order to ensure the sealing of the sealing surface of this kind of valve in the pipeline is generally should be installed horizontally.

According to the different process equipment, can choose pneumatic or electric actuator, respectively form the pneumatic ball valve and electric ball valve, if the pneumatic ball valve must be equipped with valve positioning device, electric ball valve if want to achieve proportional adjustment must choose electronic electric actuator or servo amplifier.