The pneumatic flanged ball valve is a ball valve coupled with a pneumatic actuator, which is relatively fast and does not require workers to work hand in hand, saving manpower and time to a large extent.
Pneumatic flange ball valve is evolved from the valve. It has the same rotation of 90 degrees to mention the action, the difference is that the plug body is a sphere, with a circular through hole or passage through its axis. The proportion of the spherical and the channel should be such that when the ball rotates 90 degrees, the entrance and exit should be spherical, so as to cut off the flow.
Pneumatic flange ball valve only need to rotate 90 degrees of operation and a small torque can be closed tightly. The fully equal body cavity provides a very small, straight passage for the medium. It is generally believed that the ball valve is most suitable for direct opening and closing use, but the recent development of the ball valve has been designed so that it has a throttle and control the flow of use. The main features of the ball valve itself is compact, easy to operate and repair, suitable for water, solvents, acids and natural gas and other general working medium, but also for poor working conditions such as oxygen, hydrogen peroxide, methane and ethylene. Ball valve body can be the whole, it can be modular.
A, the practical effect of pneumatic flange ball valve
Stainless steel pneumatic ball valve works by rotating the valve to make the valve open or closed. Pneumatic ball valve switch light, small size, can be made into a large caliber, sealed and reliable, simple structure, easy maintenance, sealing surface and the ball is often closed state, not easily eroded by the media, in various industries have been widely used.
Pneumatic flange ball valve in the pipeline is mainly used to do cutting speed, distribution and change the flow direction of the media. Pneumatic ball valve is widely used in recent years, a new type of valve, it has the following advantages:
1. The fluid resistance is small and the drag coefficient is equal to the pipe length of the same length.
2. Simple structure, small size, light weight.
3. Close and reliable, the current ball valve sealing material widely used plastic, good sealing, in the vacuum system has also been widely used.
4. Easy to operate, open and close quickly, from full open to full clearance as long as the rotation 90 °, easy to remote control.
5. Easy maintenance, pneumatic ball valve structure is simple, the seals are generally active, demolition and replacement are more convenient.
6. When fully open or fully closed, the ball and the valve seat sealing surface and the media isolation, the media through, will not cause the valve sealing surface erosion.
7. Applicable to a wide range of diameter from small to a few millimeters, large to a few meters, from high vacuum to high pressure can be applied.
Pneumatic three-piece ball valve has been widely used in petroleum, chemical, power generation, paper, atomic energy, aviation, rockets and other departments, as well as people’s daily lives.
B, pneumatic ball valve can be divided according to the structure:
One, floating pneumatic ball valve
The ball of the stainless steel ball valve is floating, and under the action of the medium pressure, the ball can produce a certain displacement and press it on the sealing surface of the outlet end to ensure that the outlet end is sealed.
Floating stainless steel pneumatic ball valve structure is simple, good sealing, but the ball to bear the working medium of the load all passed to the export seal, so consider the sealing material can withstand the work of the ball media load. This structure is widely used in medium and low pressure ball valves.
Second, fixed ball pneumatic ball valve
The ball of the stainless steel pneumatic ball valve is fixed and does not move after compression. Fixed ball valve with a floating seat, by the media pressure, the valve seat movement, so that the seal on the ball to ensure that the seal. Usually with the ball on the lower shaft with bearings, operating torque is small, suitable for high pressure and large diameter valves.
In order to reduce the operating torque of the pneumatic ball valve and increase the reliability of the seal, in recent years there have been oil seal ball valve, both in the sealing surface between the injection of special lubricants to form a layer of oil film, which enhances the seal, Torque, more suitable for high pressure large diameter ball valve.
Third, the elastic ball pneumatic ball valve
The ball of the pneumatic ball valve is elastic. Ball and valve seat seals are made of metal materials, sealing pressure is very large, relying on the pressure of the medium itself has been less than the requirements of the seal, you must exert external force. This valve is suitable for high temperature and high pressure medium.
The elastic sphere is an elastic groove at the lower end of the inner wall of the sphere, and is elastic. When closing the channel, use the wedge of the stem to keep the ball open and seal against the seat. Before turning the ball, loosen the wedge head, and the sphere restores the original shape, so that there is a small gap between the ball and the seat, which can reduce the friction and operating torque of the sealing surface.
Pneumatic ball valve according to its channel position can be divided into straight-through, three-way and right angle. The latter two ball valves are used to dispense media and change the flow of media.
C, pneumatic ball valve instructions
1, Range: This manual applies to the electric (or pneumatic) ball valve of the flange connection.
(20) and the ball valve body part, which is connected with the bracket (18) and the connecting shaft (17) by the electric (or pneumatic) actuator (20).
2, the use of restrictions
Temperature and pressure limits
• The nameplate shows the maximum operating pressure allowed by the ball valve at maximum and minimum operating temperatures.
L The use of PTFE or RTFE material seat and seal, the operating temperature should be between -290C to 2000C. The operating temperatures of other types of seats and seals shall be checked by the KI plant.
The nominal pressure rating (PN) of the valve indicates the maximum working pressure of the valve in the normal temperature state. (For example: PN4.0, indicating that the operating temperature of -290C ~ 380C when the maximum working pressure of 40 Bar (4.0MPa)).
L Please refer to the corresponding instructions for the precautions of electric or pneumatic actuators.
1), remove the flange on both sides of the protective cover, the valve is fully open in the state of cleaning and cleaning.
2), before installation should be in accordance with the provisions of the signal (electricity or gas) for machine testing (to prevent the vibration caused by the use of transport performance), qualified before the on-line installation (wiring by electric actuator circuit diagram).
3), ready to be connected with the pipeline before the need to rinse and remove the remaining impurities in the clean pipe (these substances may damage the seat and the ball).
4) During installation, do not use the actuator part of the valve as lifting point to avoid damage to the actuator and accessories. The
5), this type of valve should be installed in the horizontal or vertical direction of the pipeline.
6), the installation point near the pipeline can not be low or bear the phenomenon of external force, you can use the pipe support or support to eliminate the deviation of the pipeline.
7), connect with the pipe, please use the specified torque cross-locking flange connection bolts.
4, operation and use
1), make sure that the piping and valves have been flushed before operation.
2), the valve operation according to the actuator input signal size drive stem rotation is completed: forward rotation 1/4 (900), the valve off. When the reverse rotation is 1/4 turn (900), the valve opens.
3), when the actuator direction indicator arrow parallel to the pipeline, the valve is open; indicating the arrow and the pipeline is vertical, the valve is closed.
Has a long service life and maintenance-free period, will depend on the following factors: normal working conditions, maintain a harmonious temperature / pressure ratio, and reasonable corrosion data
Classification and Characteristics of Pneumatic Three – piece Ball Valves
Pneumatic ball valve with O-type ball valve and V-type ball valve points. O-type ball valve with floating structure, the core for the precision castings, the appearance of hard chrome plating, the valve seat with enhanced PTFE material, the flow channel and pipe diameter the same, great circulation, flow resistance is very small, when closed Leakage type, generally do the use of open valve, especially for high viscosity, including fiber, granular media; V-type ball valve with a fixed structure, the ball on the V-shaped incision, can achieve proportional adjustment, flow characteristics for the approximate percentage.
According to the different equipment can be used pneumatic or electric actuator, respectively, composed of pneumatic ball valve and electric ball valve, pneumatic valve, such as to achieve the proportion of adjustment to be equipped with valve positioner, electric ball valve to achieve the proportion of adjustment to be selected electronic electric actuator or Servo amplifier and so on.
From the material, can be divided into: carbon steel ball valve, stainless steel 304 ball valve, 316 ball valve and copper ball valve
With the application, 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: the main application of the media for water and other non-corrosive pipeline!
Source: China Ball Valve Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)