What is the difference between a floating ball valve a rail ball valve and a fixed ball valve? 10

Floating Ball Valve Features and Performance.

1. The ball valve is made of a ball with a circular through hole as the opening and closing parts, and the ball rotates 0 90 degrees around the center of the valve stem under the drive of the valve stem to complete the opening and closing function;

2. Small size, light weight and simple structure;

3. The sphere has the function of free floating, which can better ensure the sealing;

4. It has the characteristics of compact structure and fast switching, and can close the valve and cut off the pipeline medium by rotating 90 degrees;

5. The diameter of the spherical channel is the same as the diameter of the pipeline, the flow resistance is small, and the circulation capacity is large;

6. The valve stem is bottom-mounted, which eliminates the occurrence of the accident of valve stem penetration and ensures the safety of use;

7. The middle flange gasket is a closed structure, which prevents the pipeline stress from sealing the valve seat Structural characteristics of the orbital ball valve The switch is wear-free: the ball rotates after deviating from the valve seat, which eliminates the friction with the valve seat and solves the wear problem of the valve seat of the traditional ball valve, gate valve and plug valve.

Single seat design: The static single seat of the rail ball valve can ensure zero leakage in both directions, and avoid the problem of increasing pressure in the inner cavity of the double valve seat.

Anti-wear hard sealing surface spool: The sealing surface of the spool is surfacing with a layer of cemented carbide and polished, which can meet the sealing performance in very harsh media occasions.

Double Stem Guide Pin: The stem guide groove slides along the hard guide pin to smoothly control the lifting and rotation of the stem.

Mechanical Wedge Force: The cam slope at the lower end of the stem provides a mechanical wedge force to ensure continuous adhesion between the spool and the seat piece.

Low torque operation: because the sealing surface of the orbital ball valve is frictionless and the rotational torque is small, except for the extra-large size that requires the gear to be outward, it can be equipped with a pinion.

Optimal flow characteristics: Both the full bore and the standard bore have a high CV value, which reduces the resistance loss along the line and minimizes wear problems.

Self-cleaning: When the valve core deviates from the valve seat, the medium can flow 360 degrees along the sealing surface to flush out the impurities in the medium.

Fillable Grease: Maintenance can be carried out during operation, and the grease is injected through the grease injector to fully control the valve and prevent leakage.

Long life: Orbital ball valves can replace ordinary ball valves, gate valves, globe valves, and plug valves that are prone to failure of sealing pairs. The unique characteristics of the orbital ball valve can effectively reduce the failure rate of the device and greatly reduce the user's use and maintenance costs.

Structural features of orbital ball valves.

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

First, the structure is different:

The floating ball valve is small in size, light in weight, simple in structure, and the ball has the function of free floating, which can better ensure the sealing; The ball valve is made of a ball with a circular through hole as the opening and closing parts, and the ball rotates 0 90 degrees around the center of the valve stem under the drive of the valve stem to complete the opening and closing function.

Common actuation methods for fixed ball valves are worm gear drive, manual, electric, and pneumatic. Most fixed ball valves are flanged, but there are also fixed ball valves in welded form.

Second, the principle is different:

The ball of the floating ball valve is floating, and under the action of medium pressure, the ball can produce a certain displacement and press on the sealing surface of the outlet end to ensure that the outlet end is sealed.

The ball body of the fixed ball valve is fixed and does not move after being pressurized. Fixed ball valves are equipped with floating seats, and after being pressured by the medium, the valve seats move to make the sealing ring press against the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts with the ball, and the operating torque is small, which is suitable for high-pressure and large-diameter valves.

Features:

1. Among all kinds of valves, the flow resistance of the ball valve is the smallest, and when the full-diameter ball valve is opened, the diameter of the ball channel, the valve body channel and the connecting pipe are equal and form a diameter, and the medium can flow through almost without loss.

2. The ball valve can be fully closed and fully opened by rotating 90°, and the opening and closing are fast. Compared with gate valves and globe valves of the same specification, ball valves are small in size and light in weight, which is convenient for pipeline installation.

3. Advanced valve seat: The valve seat designed with many years of ball valve manufacturing experience ensures that the valve is sealed, the friction coefficient is low, the operating torque is small, the seat material is a variety of materials, and the application range is wide.

There are two types of ball valve trims commonly used in ball valves: floating ball valves and fixed ball valves. Some users are very confused in the selection and do not know the difference between the two, we refer to the characteristics of the American Vedun VTON, which has a relatively large amount of ball valves, to analyze their differences.

Imported floating ball valve, simple structure, relying on the medium pressure to form a seal specific pressure and achieve sealing. Therefore, the floating ball valve should not be used in larger size occasions, otherwise, when the medium pressure is low and the ball is heavier, the effect of cutting off the seal will be worse, or even can not be sealed. The floating ball valve can be either a single seat seal or a double seat seal, and the imported fixed ball valve uses a spring-supported floating seat and the spool to establish a sealing specific pressure and achieve a shut-off seal. The floating valve seat is composed of a valve seat, a sealing ring, a support spring and a sealing ring type, and the structure is complex and the structure size is also large. However, the fixed ball valve does not need the pressure of the medium to achieve sealing, the sealing is reliable, and it is easy to achieve two-way sealing, so it is often used in the case of large diameters.

It is fixed like an elastic rubber ball in the middle of the ball, and when the rubber tube ball is pinched, a gap will be created to open the valve. The floating ball is similar to the float in the storage tank behind the flush toilet, and the valve is opened or closed at a certain height.

The ball of the floating ball valve is floating, under the action of medium pressure, the ball can produce a certain displacement along the ball mandrel axis and press tightly on the valve seat sealing ring at the outlet end to ensure that the outlet end is sealed, and the inlet end can not be sealed, this floating ball valve is a single-sided forced sealing form.

The ball of the fixed ball valve is fixed with the lower valve stem, and will not move after being pressurized, therefore, the two sealing rings must have enough preload to ensure the sealing of the valve seat and the ball during the design, which is a double-sided forced seal. Thrust or plain bearings are usually installed on the upper and lower stems that are integrated with the ball.

Each has its own characteristics, there is no absolute good or bad, generally the caliber is greater than DN250 to choose a fixed ball.

Taking the American Vedun Vton ball valve as an example, there are mainly differences in appearance, working principle and functional use.

1. Appearance. 1. It is easy to distinguish between floating ball valve and fixed ball valve in appearance, if the valve body has a lower fixed shaft, it must be a fixed ball valve.

2. If there is a seat grease injection valve on the ball valve body, it is basically a fixed ball valve. But the reverse is not true, it is not correct to have a floating ball valve without a seated grease valve, because small size such as a 2" 150lb fixed ball valve usually does not have a seated grease valve.

Second, the working principle.

1. The ball of the floating ball valve only has the upper valve stem, and the ball can be slightly displaced, so it is called a floating ball valve. There is also a fixed shaft at the bottom of the ball of the fixed ball valve, which fixes the position of the ball, so it cannot be displaced, so it is called a fixed ball valve.

2. The ball of the floating ball valve is displaced due to the pressure of the medium, and it is tightly attached to the valve seat to achieve sealing, and it is necessary to consider whether the valve seat material can withstand the working pressure. The ball of the fixed ball valve is fixed, and the valve seat is driven to move by the medium pressure, and it is tightly sealed on the ball.

3. Functions and Use.

1. The floating ball valve is suitable for medium and low pressure, and the diameter is small; Fixed ball valves can withstand up to 2500lb and can be up to 60 inches in size. For example, the large-diameter and high-pressure ball valve of Weidun VTON is a fixed ball valve.

2. The fixed ball valve can realize the function of double resistance and double row, while the floating ball valve is mostly one-way sealed. When the pressure in the cavity of the valve body is greater than the tightening force of the seat spring, the valve seat will be pushed open, and the pressure in the cavity will be released, and the packaging is safe.

3. Fixed ball valves usually have a longer life than floating ball valves. According to user feedback, the Vton fixed ball valve has been used for 10 years and there is no problem.

4. The torque of the fixed ball valve is smaller than that of the floating ball valve, so the operation is more labor-saving.

5. Fixed ball valves above 4 inches are equipped with seat grease valves, and floating ball valves are not.

6. The sealing performance of the fixed ball valve is more reliable: the PTFE single material sealing ring is embedded in the stainless steel valve seat, and the tail end of the metal valve seat is equipped with a spring to ensure sufficient preload of the sealing ring.

7. The American Vedun vton friendly reminder that the cost of ball valve fixed balls of the same specification is generally higher than that of floating balls.

Generally, the floating ball valve is used more below DN200, because the weight of the ball itself can bear it, and the ball valve above DN200 generally fixes the ball more, the greater the pressure of the floating ball valve, the smaller the possibility of leakage, and the greater the pressure of the fixed ball valve, the greater the possibility of leakage.

Different types of ball valves are used in different occasions.

Floating balls are used in low-pressure situations and fixed balls are used in high-pressure situations.

The difference between a fixed ball valve and a floating ball valve is that the floating ball valve – the spool ball rotates freely between the two seat seals with the help of the stem. Fixed Ball Valve – A ball valve with a floating ball and an elastic movable sleeve and a drain seat that is connected to the stem and rotates in the center of the stem.

The floating ball valve is small in size, simple in structure, light in weight, and the ball has the function of free floating, which can better ensure the sealing. The more common driving methods for fixed ball valves are worm gear drive, manual, electric and pneumatic. Most fixed ball valves are flanged.