What is the material of the butterfly plate seal of the double eccentric soft seal butterfly valve

Soft seals are generally PTFE or rubber.

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 are the top ten domestic first-line valve brand manufacturers in 2022-2023, but for reference only: Suzhou Neway Valve Co., Ltd., Shanghai Guanlong Valve Machinery, Shanghai Qizhong Valve Manufacturing, 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.

1. The hard-sealed butterfly valve adopts a three-eccentric hard sealing structure, and the valve seat and butterfly plate are almost wear-free, and it has the sealing function of getting tighter and tighter.

2. The sealing ring is made of stainless steel, which has the dual advantages of metal hard seal and elastic seal, and has excellent sealing performance, corrosion resistance and long service life in the case of low and high temperatures.

3. The sealing surface of the butterfly plate is made of surfacing cobalt-based cemented carbide, which is wear-resistant and has a long service life.

4. The large-size butterfly leakage bent code plate adopts quilting structure, which has high strength, large overflow area and small flow resistance.

5. According to the needs of users, the hard seal butterfly valve can be designed with two-way sealing function, which is not limited by the flow direction of the medium or the influence of the space position during installation, and can be installed in any direction.

6. The noise drive device can be installed in multiple stations (rotation 90° or 180°), which is convenient for users to use.

Features of triple eccentric butterfly valves:

1. Celery lead is carefully adjusted and cut off, and the control is respectful.

In order to prevent the deformation of the butterfly plate, the dislocation of the valve stem and the occlusion of the sealing surface caused by the influence of fluid pressure and temperature, two independent thrust rings are installed on the upper and lower sides of the butterfly plate, so as to ensure the normal operation of the valve under any working conditions;

2. No dead zone design, small opening torque.

The shape of the triple eccentric butterfly valve disc is an oval cone, and its surface is welded with cemented carbide, which has excellent wear resistance. When the valve is opened, the oval cone sealing face disc first detaches from the valve seat and then rotates; When closed, the disc rotates, and under the action of the eccentric shaft, the disc automatically adjusts the center to the elastic seat, and presses the seat to deform the seat until the seat and the oval cone sealing surface of the disc are tightly matched. When the valve is opened and closed, the butterfly plate does not scratch the valve seat, and the torque of the valve stem is directly transmitted to the sealing surface through the butterfly plate, and the opening torque is small, so as to eliminate the common jumping phenomenon when opening the valve.

3. Zero leakage, high temperature and high pressure resistance.

The biggest feature of the three eccentricities is that the sealing structure is fundamentally changed, no longer position sealing, but torsion sealing, that is, it does not rely on the elastic deformation of the valve seat, but completely relies on the contact pressure of the valve seat to achieve the sealing effect. This sealing structure allows the triple eccentric butterfly valve to achieve a hard seal V I class to achieve true zero leakage. At the same time, due to the selection of metal seats and the structural characteristics of face seals, the problem of high temperature and high pressure resistance is also solved.

To withstand high temperatures, hard seals must be used, but the leakage is large; To achieve zero leakage, it is necessary to use a soft seal that is not resistant to high temperatures. In order to overcome the contradiction of double eccentric butterfly valve, the butterfly valve was eccentric for the third time. Its structural characteristics are that at the same time as the axial position of the valve stem of the double eccentricity is eccentric, the conical axis of the sealing surface of the butterfly plate is deviated from the cylindrical axis of the body, that is to say, after the third eccentricity, the sealing section of the butterfly plate is no longer a true circle, but an ellipse, and the shape of the sealing surface is also asymmetrical, one side is inclined to the center line of the body, and the other side is parallel to the center line of the body.

Since the advent of the triple eccentric disc valve, in order to meet the increasingly severe working conditions, it has also undergone a process of self-improvement and continuous development. Even the most basic zero-leakage, theoretically triple offset disc valve can be achieved, but in practice it still depends on careful design and precision manufacturing.

To sum up, the triple eccentric butterfly valve, as the crystallization of the latest technology of the valve, promotes the advantages of various valves and avoids the shortcomings of various valves, and will surely attract more and more attention from the majority of users and designers.

Especially in terms of large diameter, with its advantage of zero leakage, it is constantly replacing bulky gate valves and ball valves in shut-off valves, and similarly, with its excellent control function, it is also constantly replacing bulky shut-off valves in regulating and control valves. As a matter of fact, it has been used in a variety of important pipelines such as oil and gas extraction, offshore platforms, oil refining, petrochemical, inorganic chemical, energy and power generation and other important industrial fields such as oil and gas extraction, offshore platforms, oil refining, petrochemicals, inorganic chemicals, and energy power generation.

Features: Triple eccentric structure: offset a size A between the stem axis and the butterfly plate sealing surface, and offset a size B with the valve body channel axis, and the valve seat rotary axis and the valve body channel axis form an eccentric angle, so three eccentricities are formed.

When the butterfly valve is opened from 0° 90°, the butterfly plate sealing surface will immediately leave the seat sealing surface at the moment of opening, and when it is closed at 90° 0°, only at the moment of closing, its butterfly plate conical sealing surface will contact and compress the seat conical seal. As a result, there is no friction between the seat and the sealing surface on the butterfly plate, eliminating the possibility of wear and leakage.

Performance: Three-dimensional eccentric hard seal butterfly valve is used as the best device for adjusting the flow, cutting off or connecting the fluid on the pipelines of different media such as petroleum, chemical industry, metallurgy, electric power, food, medicine, water supply and drainage, gas transportation, etc. Using different materials, there are manual pneumatic and electric, butterfly valves can be applied to water, sewage, seawater, air, steam, gas, combustible gas, corrosive media, oil and food and other media, the maximum working temperature can reach 600.

It is widely used in industrial pipelines such as metallurgy, electric power, petrochemical industry, water supply and drainage and municipal construction, and is used to regulate flow and carry off fluid.

The advantages of the triple eccentric structure of the hard seal butterfly valve are:

The unique design of the three eccentric makes the metal hard seal start to be more labor-saving, when the valve is opened and closed, there is no friction between the butterfly plate and the valve body during rotation, when the valve is closed, the torque of the transmission mechanism increases to provide a compensating seal, which greatly improves the sealing performance of the triple eccentric butterfly valve, and prolongs the service life of the butterfly valve.

There are nine sealing materials for butterfly valves:

x1 (natural food glue);

x2 (Hypalen);

x3 (ethylene propylene monomer);

x4 (neoprene);

x5 (nitrile rubber);

x6 (abrasion resistant rubber);

x7 (fluoroelastomer);

x8 (silicone rubber);

x9 (heat-resistant ethylene propylene rubber).

Butterfly valve, also known as flap valve, is a simple structure of the regulating valve, which can be used for the on-off control of low-pressure pipeline medium butterfly valve refers to the shut-off part (disc or butterfly plate) as a disc, rotating around the valve shaft to achieve opening and closing of a kind of valve, the valve can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. It mainly plays the role of cutting and throttling on the pipeline. The butterfly valve opening and closing part is a disc-shaped butterfly plate, which rotates around its own axis in the valve body, so as to achieve the purpose of opening and closing or adjusting.

The soft seal is generally: PTFE, and the valve body is generally cast iron.

Part Name Material Valve Body Various rubber, PTFE.

Butterfly plate Gray cast iron, ductile steel, cast steel, stainless steel and special material sealing ring Ductile steel, cast steel, alloy steel, stainless steel stem 2Cr13, stainless steel.

Filler: O-ring, flexible graphite.

Valve body: ductile iron QT450 valve body seal: stainless acid-resistant steel 1Cr18Ni9Ti

Valve plate: ductile iron QT450 valve plate seal: stainless acid-resistant steel 1Cr18Ni9Ti

Valve shaft: stainless steel 2Cr13 Valve shaft seal: flexible graphite shaft sleeve:

Tin Bronze Worm Gear Box: Ductile Iron QT450 Worm Gear: Ductile Iron QT450 Worm Gear Box Seal:

Nitrile NBR Worm: Stainless Steel 2CR13 Handwheel or Square Head: Ductile Iron QT450 Valve Shaft Seal Adjustment Bolt:

Stainless steel 2CR13 Body adjustment telescopic limit bolt: stainless steel 2CR13

As a component used to realize the on-off and flow control of pipeline system, butterfly valve has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower, etc. In the well-known butterfly valve technology, its sealing form is mostly a sealing structure, and the sealing materials are rubber, PTFE, etc. Due to the limitation of structural characteristics, it is not suitable for high temperature resistance, high pressure resistance, corrosion resistance, wear resistance and other industries.

At present, a relatively advanced butterfly valve is a three-eccentric metal hard seal butterfly valve, the valve body and the valve seat are conjoined components, and the surface layer of the valve seat seal is welded with temperature-resistant and corrosion-resistant alloy materials. The multi-layer soft-stacked sealing ring is fixed on the valve plate, this butterfly valve has high temperature resistance, light operation, no friction in opening and closing, and compensates for the sealing with the increase of the torque of the transmission mechanism when closing, which improves the sealing performance of the butterfly valve and prolongs the service life.

The butterfly plate of the triple eccentric hard seal butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°, and when the rotation reaches 90°, the valve is fully open. The characteristics of the new high-life stainless steel butterfly valve and the problems that the butterfly valve has during use.

The triple eccentric hard seal butterfly valve is widely used in metallurgy, electric power, petrochemical, water supply and drainage and municipal construction industrial pipelines with a medium temperature of 425 to regulate the flow and cut off the fluid.