What is the difference between one piece ball valve, two piece ball valve and three piece ball valve

The fundamental difference between one-piece ball valve, two-piece ball valve and three-piece ball valve is in the valve body structure.

The one-piece ball valve is held in place by a plug head, which makes it easy to maintain.

The two-piece ball valve is fixed by two pieces of valve body clamping the ball, and the maintenance is relatively complicated, and the tightness of the screw in the middle is very critical, which is related to whether there is air leakage.

The three-piece ball valve is similar to the two-piece ball valve, but with an additional body in the middle of the ball, which is clamped by neck flanges on both sides.

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.

Difference Between One-Piece Ball Valve, Two-Piece Ball Valve and Three-Piece Ball Valve:

According to the structure, the threaded ball valve with internal thread is divided into one-piece ball valves, two-piece ball valves and three-piece ball valves, and understanding their characteristics and differences will help us choose the right ball valve to use.

First of all, let's understand what is a one-piece ball valve, a two-piece ball valve and a three-piece ball valve.

One-piece ball valve refers to a ball valve with a small diameter of internal thread connection, composed of an integral one-piece valve body, and an integral valve body, which is often used for small-sized valves.

Two-piece ball valve, also known as two-piece ball valve, refers to a small-diameter internal thread connection, the valve body is divided into two parts, buckle form, usually used valve.

Three-piece ball valves, which are internally threaded, and the valve body is composed of three parts, are usually used for larger and more important valves.

Their differences and characteristics can be analyzed from the following aspects:

1. Distinguish from the structure.

The one-piece ball valve is an integrated type composed of balls, tetrafluorine rings, and lock nuts, and the diameter of the ball is slightly smaller than the diameter of the pipe, similar to the wide-type ball valve, which is generally a reduced diameter, and the actual flow of the aperture is one size less than the diameter DN, and the flow rate is relatively small.

The two-piece ball valve is composed of two parts, the sealing effect is better than that of the one-piece ball valve, the diameter of the ball is the same as that of the pipe, and it is easier to disassemble than the one-piece ball valve.

The three-piece ball valve is composed of three parts, the bonnet on both sides and the middle valve body, the three-piece ball valve is different from the two-piece ball valve and the one-piece ball valve in that it is easy to disassemble and maintain. Stronger pressure resistance.

2. Distinguish from pressure.

The pressure resistance of three-piece ball valves is much higher than that of one-piece and two-piece ball valves. The outer edge of the main three-piece ball valve is held in place by four bolts, which plays a good tightening role. Precision cast body can be pressured up to 1000 psi. Higher pressures require a forged body.

3. Distinguish from an economic point of view.

Because the main body material of the one-piece ball valve is less than the other two types, it is preferential and has the same use as the wide ball valve. The two-piece ball valve is higher than the one-piece type, and the three-piece valve body is composed of three parts in line with higher pressure resistance, and the material is higher than the other two types.

The difference between one-piece ball valve and two-piece ball valve1. The working principle is different: the working principle of one-piece ball valve is the mechanical pressure effect of the valve stem; The two-piece ball valve works by rotating the spool to keep the valve open or occluded.

2. The valve body is different: the one-piece type is fixed by a plug head to fix the ball; The two-piece ball valve is fixed by two pieces of the valve body clamping the ball, and the maintenance is relatively complicated, and the tightness of the bolt in the middle is very critical.

3. The closing parts are different: the closing parts of the one-piece ball valve are a ball, and the ball rotates around the center line of the valve body to achieve a valve that opens and closes; Two-piece ball valves, on the other hand, have no special requirements.

The one-piece ball valve structure is integral, and the ball is stabilized by a plug head, so that it can be convenient during maintenance, and the caliber of the ball valve is also small, and the ball is put into it from one side of the valve body, and the valve seat should be screwed in, and then the ball is pressed.

The two-piece ball valve is composed of bolts on the left and right two valve bodies, and the two-piece valve body is clamped when fixed, and the maintenance is relatively difficult, and the key is to see how tight the screws in the middle are, which is directly related to whether the seal is tight.

1. The working principle of one-piece ball valve and two-piece ball valve is different: the working principle of one-piece ball valve is the mechanical pressure effect of the valve stem; The working principle of the two-piece ball valve is to make the valve open or occluded by rotating the valve.

2. The valve body of one-piece ball valve and two-piece ball valve is different: the one-piece type is fixed by a plug head; The two-piece ball valve is fixed by two pieces of the valve body clamping the ball, and the maintenance is relatively complicated, and the tightness of the bolt in the middle is very critical.

3. The closing parts of one-piece ball valves and two-piece ball valves are different: the closing parts of one-piece ball valves are a ball, and the balls rotate around the center line of the valve body to achieve opening and closing; Two-piece ball valves, on the other hand, have no special requirements.

1. Disassembly difference:

The one-piece type is a wide type ball valve. Two-piece ball valves are easier to remove than one-piece ones.

2. Structural differences:

The one-piece ball valve is fixed by a plug head, which is small in size, reliable in sealing, simple in structure and easy to maintain. The one-piece type is a reduced diameter, and the actual flow diameter is smaller than the thread diameter.

The two-piece ball valve is fixed by two pieces of valve body clamping the ball, and the maintenance is relatively complicated, and the tightness of the bolt in the middle is very critical, which is related to whether it leaks. Two-piece ball valves are not suitable for high pressures.

There is no difference in the working principle, but the installation method and structural form are different.

The structure of the valve body is different, the one-piece gland should be opened and the disc should be replaced, while the two-piece stone should be opened with the connecting bolts of the valve body and the disc replaced. The media that can be used is also different, OWG's can generally be used for both, but the one-piece type can be used for some high-pressure working conditions or toxic media that require quick opening and closing.

The working principle of one-piece ball valves, that is, wide ball valves, is to rely on rotary valves to make the valve unblocked or occluded. The ball valve switch is lightweight, small in size, can be made into a large caliber, reliable sealing, simple structure, easy maintenance, the sealing surface and the spherical surface are often in a closed state, not easy to be eroded by the medium, and have been widely used in various industries.

Structural features of two-piece ball valve:

1. There is no friction in opening and closing. This function completely solves the problem of traditional valves affecting the sealing due to the friction between the sealing surfaces.

3. Single seat design. It eliminates the problem that the medium in the cavity of the valve affects the safety of use due to abnormal pressure increase.

4. Low torque design. The valve stem with special structure design can be easily opened and closed with only a small handle valve.

5. Wedge-shaped sealing structure. The valve is sealed by the mechanical force provided by the valve stem to press the ball wedge to the valve seat, so that the sealing of the valve is not affected by the change of pipeline pressure, and the sealing performance is reliably guaranteed under various working conditions.

6. Self-cleaning structure of sealing surface. When the ball is tilted away from the valve seat, the fluid in the pipeline passes evenly along the sealing surface of the ball at 360°, which not only eliminates the local scouring of the valve seat by the high-speed fluid, but also washes away the accumulation on the sealing surface to achieve the purpose of self-cleaning.

Three-piece ball valves offer the following advantages:

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

2. Simple structure, small size and light weight.

3. Tight and reliable, the sealing surface material of the ball valve is widely used plastic, with good sealing, and has been widely used in the vacuum system.

4. Easy to operate, fast opening and closing, from full open to full closed, only need to rotate 90°, which is convenient for long-distance control.

5. Easy maintenance, simple structure of ball valve, sealing ring is generally movable, and it is more convenient to disassemble and replace.

6. When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium, and the erosion of the sealing surface of the valve will not be caused when the medium passes.

7. Wide range of application, from small to a few millimeters in diameter, from high vacuum to high pressure.