Overview of Pneumatic High Platform Ball Valve Products

Connection form: flange connection Nominal diameter: 1/2 "-4" Applicable media: water, oil, steam Pressure range: 1.6, 2.4, 6.4 (Mpa). Applicable temperature:- 40~150（°C）. Opening and closing force N: 300-400 Main materials: 304 and 316 Design and production adopt: international standards, Designed and produced according to standards such as ISO, API, GB, BS, etc., their safety and quality have been strictly handled and distributed to domestic and international markets

The working principle of a ball valve is to rotate the valve to make it open or close. Ball valve switches are lightweight, small in size, can be made into large diameters, reliable in sealing, simple in structure, easy to maintain, and the sealing surface and spherical surface are often in a closed state, which is not easily eroded by media. They are widely used in various industries.

　　The working principle and practical application of ball valves

Ball valves and plug valves belong to the same type of valve, except that their closing element is a sphere that rotates around the centerline of the valve body to achieve opening and closing.

Ball valves are mainly used in pipelines to cut off, distribute, and change the flow direction of media. Ball valve is a new type of valve widely used in recent years, which has the following advantages:

1. The fluid resistance is small, and its resistance coefficient is equal to that of a pipe segment of the same length.

2. Simple structure, small size, and light weight.

3. Tight and reliable, plastic is widely used as the sealing surface material for ball valves with good sealing performance, and it has also been widely used in vacuum systems.

4. Easy to operate, quick opening and closing, only need to rotate 90 ° from fully open to fully closed, making it convenient for remote control.

5. Easy to maintain, ball valve structure is simple, and the sealing ring is generally movable, making disassembly and replacement relatively convenient.

6. When fully open or fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium, and when the medium passes through, it will not cause erosion of the valve sealing surface.

7. Widely applicable, with diameters ranging from a few millimeters to several meters, suitable for applications from high vacuum to high pressure.

Ball valves have been widely used in various sectors such as petroleum, chemical, power generation, papermaking, atomic energy, aviation, rockets, as well as in people's daily lives.

　　Ball valves can be classified according to their structural form

　　Floating ball valve

The ball of a ball valve is floating, and under the pressure of the medium, the ball can produce a certain displacement and press tightly against the sealing surface at the outlet end, ensuring the sealing of the outlet end.

The structure of a floating ball valve is simple and has good sealing performance, but the ball bears all the load of the working medium and is transmitted to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used for medium and low pressure ball valves.

　　Fixed ball valve

The ball of a ball valve is fixed and does not move under pressure. Fixed ball valves are equipped with floating seats, which move when subjected to medium pressure, causing the sealing ring to press tightly against the ball to ensure sealing. Usually, bearings are installed on the upper and lower shafts of the sphere, with a small operating torque, suitable for high-pressure and large-diameter valves.

In order to reduce the operating torque of ball valves and increase the reliability of sealing, oil sealed ball valves have emerged in recent years. They inject special lubricating oil between the sealing surfaces to form an oil film, which enhances sealing performance and reduces operating torque, making them more suitable for high-pressure and large-diameter ball valves.

　　Elastic ball valve

The ball of a ball valve is elastic. The ball and valve seat sealing ring are both made of metal materials, and the sealing pressure ratio is very high. Relying on the pressure of the medium itself cannot meet the sealing requirements, and external force must be applied. This type of valve is suitable for high temperature and high pressure media.

An elastic sphere is obtained by creating an elastic groove at the lower end of its inner wall. When closing the channel, use the wedge-shaped head of the valve stem to expand the ball and press it against the valve seat to achieve sealing. Release the wedge-shaped head before rotating the sphere, and the sphere will return to its original shape, creating a small gap between the sphere and the valve seat, which can reduce friction and operating torque on the sealing surface.

Ball valves can be divided into straight through, three-way, and right angle types according to their channel positions. The latter two types of ball valves are used for distributing media and changing the flow direction of media.

　　Ball valve manual

1. Scope: This manual is applicable to electric (or pneumatic) ball valves with flange connections.

2. Composition: It consists of an electric (or pneumatic) actuator (20) and a ball valve body, connected by a bracket (18) and a connecting shaft (17).

3. Usage restrictions: Temperature and pressure limitations

A The nameplate displays the maximum operating pressure allowed by the ball valve at the maximum and minimum operating temperatures.

B The operating temperature for valve seats and seals made of PTFE or RTFE materials should be between -290C and 2000C. The operating temperature of other types of valve seats and seals should be checked by KI factory.

C The nominal pressure rating (PN) of a valve indicates its maximum working pressure at normal temperature. (For example: PN4.0， Indicating that its maximum working pressure is 40 Bar (4.0MPa) when operating at temperatures between -290C and 380C.

D Please refer to the corresponding manual for the precautions of electric or pneumatic actuators.

4. Installation

1) Remove the protective covers on both sides of the flange end and rinse and clean with the valve fully open.

2) Before installation, the entire machine should be tested according to the specified signal (electric or gas) to prevent vibration from affecting performance during transportation. Only after passing the test can it be installed online (wiring should follow the electric actuator circuit diagram).

3) Before connecting to the pipeline, it is necessary to flush and remove any remaining impurities in the pipeline (which may damage the valve seat and ball).

4) During installation, please do not use the actuator part of the valve as a lifting point to avoid damaging the actuator and accessories

5) This type of valve should be installed in the horizontal or vertical direction of the pipeline.

6) The pipeline near the installation point should not have any low hanging or external force bearing phenomenon, and pipeline supports or supports can be used to eliminate the deviation of the pipeline.

7) After connecting to the pipeline, please cross tighten the flange connection bolts with the specified torque.

5. Operation and use

1) Before operation, it is necessary to confirm that the pipelines and valves have been flushed.

2) The operation of the valve is completed by driving the valve stem to rotate according to the input signal of the actuator: when it rotates forward 1/4 turn (900), the valve closes. When rotating 1/4 turn in reverse (900), the valve opens.

3) When the direction indicator arrow of the actuator is parallel to the pipeline, the valve is in the open state; When the arrow is perpendicular to the pipeline, the valve is in the closed state.

6. Repair

Having a long service life and maintenance free period will depend on the following factors: normal working conditions, maintaining a harmonious temperature/pressure ratio, and reasonable corrosion data attention:

When the ball valve is in the closed state, there is still pressurized fluid inside the valve body

Before maintenance, relieve the pipeline pressure and keep the valve in the open position

Before maintenance, disconnect the power or gas source

Before maintenance, detach the actuator from the bracket

1) The filling area needs to be locked again

If there is slight leakage at the filling culvert, the valve stem nut (13) must be tightened again

Be careful not to lock it too tightly. Usually, lock it 1/4 turn to 1 turn again, and the leakage will stop.

2) Replace the valve seat and seals

A) Dismantling

Keep the valve in the half open position, flush and remove any hazardous substances that may exist inside and outside the valve body

Close the ball valve, remove the connecting bolts and nuts on both flanges, and then completely remove the valve from the pipeline.

Disassemble the drive device actuator (20), connecting bracket (18), anti loosening washer (14), valve stem nut (13), butterfly spring plate (12), Gnan (11), wear-resistant plate (10), valve stem packing (9) in sequence. Remove the body cover connecting bolt (5) and nut, separate the valve cover from the valve body, and remove the valve cover gasket (16).

Confirm that the valve ball (3) is in the "off" position, which makes it easier to remove it from the valve body and then remove the valve seat.

Gently push the valve stem (6) downwards from the hole in the valve body until it is completely removed, then remove the O-ring (8) and the lower packing (7) of the valve stem. Caution: Please operate carefully to avoid scratching the surface of the valve stem and the sealing part of the valve body packing box (B), and reassemble

Clean and inspect the disassembled parts, and it is strongly recommended to replace the valve seat, valve cover gasket, and other sealing components with a spare parts kit. Assemble them in the reverse order of disassembly.

Use the specified torque to cross lock the flange connection bolts (5).

Tighten the valve stem nut (13) with the specified torque

After installing the actuator, input the corresponding signal to drive the valve core to rotate by rotating the valve stem, causing the valve to reach the open and closed positions.

If possible, please conduct pressure sealing and performance tests on the valve according to relevant standards before reinstalling the pipeline.