Pneumatic ball valve, three-piece ball valve, worm ball valve, ball valve, stainless steel ball valve Evolution: Pneumatic ball valves evolved from plug valves. It has the same 90 degree rotation, except that the plug body is a sphere with a circular through hole or passage through its axis. The ratio of the spherical surface to the passage opening should be such that when the ball is rotated 90 degrees, the spherical surface should be entirely present at the inlet and outlet to intercept the flow. This type of valve can be installed in any position in the pipeline. The pneumatic ball valve works by rotating the valve plug to make the valve unblocked or occluded. The pneumatic ball valve switch is light in weight, small in size, can be made into a large diameter, reliable in sealing, simple in structure, convenient in maintenance, and the sealing surface and the spherical surface are often closed. The non-pneumatic ball valve is easily eroded by the medium and is widely used in various industries. The pneumatic ball valve and the plug valve are the same type of valve, only the closing member of which is a ball, and the ball rotates around the center line of the valve body to open and close a valve. 1. The fluid resistance is small, and its resistance coefficient is equal to the pipe length of the same length. 2. The structure is simple, small in size and light in weight. 3. It is compact and reliable. At present, the sealing surface material of the ball valve is widely used in plastic and has good sealing performance. It has also been widely used in vacuum systems. 4. The operation is convenient, the opening and closing is rapid, and the rotation is 90° from full opening to full closing, which is convenient for long-distance control. 5. The maintenance is convenient, the pneumatic ball valve has a simple structure, the sealing ring is generally active, and the disassembly and replacement are relatively convenient. 6. When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium, and the medium does not cause erosion of the sealing surface of the valve. 7. Wide range of applications, from small to a few millimeters, up to a few meters, from high vacuum to high pressure can be applied. 8. Because the power source of the pneumatic ball valve is gas, it is generally 0.2-0.8MPa pressure, which is relatively safe. If the pneumatic ball valve leaks, the gas can be directly discharged compared with the hydraulic and electric motors, and it has no pollution to the environment and has high safety. 9. Compared with manual and turbo rotating ball valves, pneumatic ball valves can be configured with large diameters. (Manual and turbo rotating ball valves are generally below DN300 caliber, and pneumatic ball valves can currently reach DN1200 caliber.) Pneumatic ball valves have been widely used in petroleum, chemical, power generation, paper, atomic energy, aviation, rocket and other departments, as well as people's daily lives. First, the floating pneumatic ball valve The ball of the pneumatic ball valve is floating. Under the action of the medium pressure, the ball can generate a certain displacement and press on the sealing surface at the outlet end to ensure the sealing of the outlet end. The floating pneumatic ball valve has a simple structure and good sealing performance, but the load of the ball subjected to the working medium is all transmitted to the outlet sealing ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the spherical medium. This structure is widely used in medium and low pressure ball valves. Second, fixed ball pneumatic ball valve The ball of the pneumatic ball valve is fixed and does not move after being pressed. The fixed ball valve has a floating valve seat. After the medium pressure, the valve seat moves, so that the sealing ring is pressed against the ball to ensure the seal. Usually mounted on the upper and lower shafts of the ball, the 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, an oil-sealed ball valve has appeared, which injects a special lubricating oil between the sealing faces to form an oil film, which enhances the sealing property and reduces the operation. Torque is more suitable for high pressure and large diameter ball valves. Pneumatic ball valve instruction manual 1 Scope 2) Before installation, the whole machine test should be carried out according to the specified signal (electricity or gas) (to prevent the use of vibration due to transportation). After passing the test, it can be installed on the line (wiring according to the electric actuator circuit diagram). 3) Before installing the pipe, flush and remove the remaining impurities in the pipe (these materials may damage the seat and the ball). 4) During installation, please do not use the actuator part of the valve as a lifting point for lifting to avoid damage to the actuator and accessories. . 5) This type of valve should be installed in the horizontal or vertical direction of the pipe. 6) The pipe near the installation point should not have the phenomenon of drooping or bearing external force. Pipe brackets or supports can be used to eliminate the deviation of the pipeline. 7) After connecting with the pipe, cross-tighten the flange connection bolt with the specified torque. 4, operation and use 1) Confirm that the pipeline and valve have been flushed before operation. 2), the operation of the valve according to the size of the input signal of the actuator to drive the valve stem to complete: when the forward rotation of 1/4 turn (90 °), the valve is closed. The valve opens when rotated 1/4 turn (90°) in the opposite direction. 3) When the actuator direction indicator arrow is parallel to the pipeline, the valve is open; when the indicator arrow is perpendicular to the pipeline, the valve is closed. Classification and characteristics of pneumatic ball valves Pneumatic ball valves are divided into O-type pneumatic ball valves and V-type pneumatic ball valves. O-type pneumatic ball valve adopts floating structure, the core is precision casting, the surface is hard chrome-plated, the valve seat is made of reinforced PTFE material, the flow port is the same as the pipe diameter, the circulation capacity is great, the flow resistance is very small, when closed No leakage, generally used as an on-off valve, especially suitable for high viscosity, V-type ball valve with fixed structure, V-shaped slit on the core, can achieve shear fiber-containing, granular media, depending on the process equipment, pneumatic or The electric actuators respectively constitute a pneumatic ball valve and an electric ball valve. Among them, the pneumatic ball valve must be equipped with a valve positioner for proportional adjustment, and the electric ball valve must be electronically operated or equipped with a 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 pressing 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, etc. Industry low-pressure pneumatic ball valve: mainly used in corrosive pipelines such as water!
Working principle Pneumatic ball valve only needs to be rotated by 90 degrees with a pneumatic actuator and a small rotating torque can be closed tightly. The fully equal valve body cavity provides a small, straight-through flow path for the medium. Ball valves are generally considered to be the most suitable for opening and closing, but recent developments have designed ball valves to throt and control flow. The main features of the ball valve are its compact structure, easy operation and maintenance, suitable for general working media such as water, solvent, acid and natural gas, and also suitable for medium with harsh working conditions such as oxygen, hydrogen peroxide, methane and ethylene. The ball valve body may be integral or combined.
The practical effect of pneumatic ball valve
Advantages Pneumatic ball valves are mainly used in pipelines to cut off quickly, distribute and change the flow direction of the medium. Pneumatic ball valve is a new type of valve widely used in recent years, which has the following advantages:
Pneumatic ball valves can be divided according to the structure:
Third, the elastic ball pneumatic ball valve The ball of the pneumatic ball valve is elastic. Both the ball and the seat ring are made of metal material, and the sealing pressure is very large. The pressure of the medium itself cannot meet the sealing requirements, and an external force must be applied. This valve is suitable for high temperature and high pressure media. The elastic sphere is made by opening an elastic groove at the lower end of the inner wall of the sphere to obtain elasticity. When the passage is closed, the wedge of the valve stem is used to open the ball and press against the seat to seal. Before the ball is rotated, the wedge head is loosened, and the ball is restored to its original shape, so that a small gap occurs between the ball and the valve seat, which can reduce the friction and operating torque of the sealing surface. Pneumatic ball valves can be divided into straight-through, three-way and right-angle according to their channel position. The latter two ball valves are used to distribute the medium and change the direction of the medium.
This manual applies to electric (or pneumatic) ball valves at flanged ends.
2. Composition The electric (or pneumatic) actuator (20) and the ball valve body portion are connected to the bracket (18) and the connecting shaft (17).
3. Limitations of use Temperature and pressure limits l The nameplate shows the maximum operating pressure allowed for the ball valve at maximum and minimum operating temperatures. l Use PTFE or RTFE seat and seals, operating temperature should be between 150 degrees and 200 degrees. Operating temperatures for other types of seats and seals are subject to inspection by the KI facility. The nominal pressure rating (PN) of the low temperature valve indicates the maximum working pressure of the valve at normal temperature. (Example: PN4.0, indicating that the maximum operating pressure at operating temperatures of -290C to 380C is 40 Bar (4.0 MPa)). l For the notes on electric or pneumatic actuators, refer to their respective instructions.
4. Installation 1) Remove the protective cover on both sides of the flange end and clean it with the valve fully open.
5, maintenance 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 Note: ◠Ball valve in the closed state, the valve body There is still a pressurized fluid inside. ◠Before the maintenance, the line pressure is released and the valve is in the open position. ◠Before the maintenance, disconnect the power supply or the air supply. ◠Before the maintenance, remove the actuator from the bracket. 1) Fill the packing and lock it again. There is micro-bleed at the filler culvert, and the stem nut (13) must be locked again. l Be careful not to lock too tightly, usually lock 1/4 turn to 1 turn, the leak will stop. 2) Replace the seat and seal. A) Disassemble l Put the valve in the half-open position to flush and remove dangerous substances that may exist inside and outside the valve. l Close the ball valve and remove the connecting bolts and nuts on the flanges on both sides. The valve is then completely removed from the line. l Disassemble the drive unit-actuator (20), connecting bracket (18), lock washer (14), stem nut (13), butterfly shrapnel (12), Glam (11), wear-resistant piece (10), stem packing (9) l Remove the body cover connecting bolt (5) and nut, separate the bonnet from the valve body, and remove the bonnet gasket (16). l Confirm that the ball (3) is in the “OFF†position, which makes it easier to remove it from the valve body and then remove the seat. l Push the valve stem (6) down from the hole in the valve body until it is completely removed, then remove the O-ring (8) and the stem under the packing (7). Note: Be careful to avoid scratching the stem surface and valve. Body stuffing box sealing part B), reassembly l Cleaning and inspection of the removed parts, it is strongly recommended to replace the valve seat and bonnet gasket with a spare parts package. l Assembly in the reverse order of disassembly. l Cross-tighten the flange connection bolts (5) with the specified torque. l Lock the stem nut (13) with the specified torque. l After installing the actuator, input the corresponding signal to rotate the spool through the rotary stem to open the valve to the open and closed positions. l If possible, perform pressure sealing test and performance test on the valve according to relevant standards before returning the pipe. D, model representation: Like the previous valve Q11S-16C, the "S" is the older method, and the "S" is the plastic seal. It is now represented by "F". It represents PTFE or PTFE.