triple eccentric butterfly valve Archives

What is the principle of triple eccentric butterfly valve

February 11, 2022

Triple eccentric butterfly valve is a kind of butterfly valve with outstanding performance in industrial pipelines. According to the sealing form, triple eccentric butterfly valve belongs to the category of hard sealing butterfly valve. Therefore, the triple eccentric butterfly valve has the characteristics of a hard-sealed butterfly valve, which is

D943H-16C-metal seated stainless steel electric triple offset butterfly valve

resistant to high temperature, erosion, and has a long service life. And because the triple eccentric butterfly valve directly welds the high temperature corrosion resistant alloy material on the valve seat surface, the valve also has the same excellent sealing performance as the soft sealing butterfly valve. So what is the principle of triple eccentric butterfly valve? What are the three eccentricities of the triple eccentricity? Why use a triple eccentric structure?

The sealing surface of the triple eccentric butterfly valve is an inclined conical surface. The valve seat of the valve body is in contact with the sealing ring of the butterfly plate. Its working principle is to drive the movement of the butterfly plate by operating the transmission device. During the movement of the butterfly plate, its sealing The ring is in full contact with the valve seat because of the elastic deformation to achieve the seal.
A prominent feature of the triple eccentric butterfly valve is that the sealing structure of the valve is changed. It is no longer a traditional position seal, but a torsion seal, that is to say, it does not rely on the elastic deformation of the valve seat to achieve sealing, but relies on the sealing surface of the butterfly plate. The contact surface pressure with the valve

triple eccentric butterfly valve-wafer-lug-double flange-welded (5)

seat is used to achieve the sealing effect, which also solves the problem of large leakage of the metal valve seat, and because the contact surface pressure is proportional to the medium pressure, the triple eccentric butterfly valve has a strong high pressure and high temperature resistance.

Three eccentric butterfly valve three eccentric
The first eccentricity: the deviation from the plane of the sealing surface to the centerline of the valve stem;
The second eccentricity: the distance from the centerline of the valve body to the centerline of the stem;
The third eccentricity: there is an included angle between the center line of the cone surface where the sealing surface of the valve body is located and the center line of the valve body channel.

Reasons for using triple eccentric structure
The use of triple eccentric structure can reduce the friction between the sealing surface of the disc and the sealing surface of the valve body when opening or closing, so that the disc can quickly disengage or release the valve seat when the triple eccentric butterfly valve is opened or closed, reducing the operation time. torque, the operation is more labor-saving and light, and the service life of the sealing surface of the butterfly valve is increased.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Video of triple eccentric butterfly valve:

Advantages and Disadvantages of Triple Eccentric Butterfly Valves

January 21, 2022

The triple eccentric butterfly valve is a new type of butterfly valve product. Before the advent of the triple eccentric butterfly valve, the soft sealing butterfly valve and the single eccentric double eccentric metal hard sealing butterfly

triple eccentric butterfly valve-

valve were the most used in industrial pipelines. These two types of butterfly valves have their own advantages, but also have obvious disadvantages. The advantage of soft sealing butterfly valve is that it has good sealing performance and can achieve zero leakage; the disadvantage is that it is not suitable for high temperature and high pressure environment and is not resistant to wear. The advantage of hard sealing butterfly valve is that it can adapt to high temperature and high pressure working conditions, but the sealing performance is very poor. In order to solve the shortcomings of the two types of butterfly valves and better serve our production work, the triple eccentric butterfly valve came into being and has been widely used.

Advantages of triple eccentric butterfly valve
The triple eccentric butterfly valve also belongs to the metal hard sealing butterfly valve. The technology makes the triple eccentric butterfly valve more resistant to high temperature and high pressure environment and more corrosion resistant than traditional butterfly valve products. At the same time, due to the unique design of the triple eccentricity, the valve is very easy to operate. When opening and closing, the disc and the valve body have no friction. When the valve is closed, the torque of the transmission mechanism increases to provide a compensation seal, which greatly improves the triple eccentricity. The sealing performance of the butterfly valve also prolongs the service life of the butterfly valve. So what do the three eccentricities of the triple eccentricity mean?
1st eccentric: The valve shaft is located behind the valve plate shaft, allowing the seal to have a complete tight encircling contact with the entire valve seat.
The second eccentricity: the centerline of the valve shaft is offset from the centerline of the pipe and valve, which is free from the interference of valve opening and closing.
3rd eccentricity: The valve seat cone shaft is offset from the centerline of the valve shaft, which eliminates friction during closing and opening and achieves a uniform compression seal around the entire valve seat.

Disadvantages of triple eccentric butterfly valve
No matter how perfect things are, there will be more or less defects and imperfections, and the triple eccentric butterfly valve is no exception. Its shortcomings have the following two points:
1. Due to the special process of the triple eccentric butterfly valve, the structure of the butterfly plate will be relatively thick, so if a butterfly valve with a triple eccentric structure is used on a small-diameter pipeline, the resistance of the butterfly plate to the circulating medium in the pipeline will be very large in the open state, and the flow of The resistance is large, so generally speaking, the triple eccentric butterfly valve is not suitable for small diameter pipelines below DN200.
2. In the normally open pipeline, the sealing surface of the valve seat of the triple eccentric butterfly valve and all layers of the sealing ring on the butterfly plate will be washed by the front, which will affect the sealing performance of the valve for a long time.

The above is the introduction of Tanghai valve for the advantages and disadvantages of triple eccentric butterfly valve. If you have purchase requirements for triple eccentric butterfly valves, you are welcome to inquire.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Video of triple eccentric butterfly valve:

Which valves are used for wastewater and sewage treatment

January 20, 2022

Which valves are used for wastewater and sewage treatment? The continuous increase of water pollution in my country has made the sewage treatment and regeneration industry receive unprecedented attention. In the sewage treatment pipeline system, the valve plays a very important role.

marine valve; butterfly valve; check valve; gate valve; manufacturer in China

Definition of sewage treatment
Sewage treatment: The process of purifying sewage in order to make it meet the water quality requirements for discharge into a body of water or for reuse. Sewage treatment is widely used in construction, agriculture, transportation, energy, petrochemical, environmental protection, urban landscape, medical treatment, catering and other fields, and is increasingly entering the daily life of ordinary people.

Sewage treatment classification
According to the classification of sewage sources, sewage treatment is generally divided into production sewage treatment and domestic sewage treatment. Production sewage includes industrial sewage, agricultural sewage and medical sewage, etc., while domestic sewage is sewage generated in daily life, which refers to the complex mixture of various forms of inorganic and organic substances, including: ① floating and suspended solid particles; ② glue shape and gel-like diffusion; ③ pure solution.
According to the quality of water pollution, there are two types of water pollution: one is natural pollution; the other is man-made pollution. At present, man-made pollution is the most harmful to water bodies. Water pollution can be divided into three categories: chemical pollution, physical pollution and biological pollution according to the different pollution impurities. The main pollutants are: (1) industrial wastewater discharged without treatment; (2) domestic sewage discharged without treatment; (3) farmland sewage with extensive use of chemical fertilizers, pesticides, and herbicides; (4) industrial waste and domestic garbage piled up by the river ; ⑸ soil erosion; ⑹ mine sewage.

Sewage treatment valve
Modern sewage treatment technology can be divided into primary, secondary and tertiary treatment according to the degree of treatment. Generally, the degree of sewage treatment is determined according to the water quality and the destination of the treated water. The valves used at each level are also different.
primary treatment
It mainly removes suspended solid pollutants in sewage, and most of the physical treatment methods can only complete the requirements of primary treatment. After primary treatment of sewage, BOD can generally be removed by about 30%, which does not meet the discharge standard. The primary treatment belongs to the preprocessing of the secondary treatment. Valves and their pipeline accessories are used: knife gate valve, triple eccentric butterfly valve, filter, etc.
secondary processing
It mainly removes colloidal and dissolved organic pollutants (BOD, COD substances) in the sewage, and the removal rate can reach more than 90%, so that the organic pollutants can meet the discharge standard, and the suspended solids removal rate can reach 95%, and the effluent effect is good. The valves used are soft-sealed butterfly valves, gate valves, ball valves, check valves, etc.
tertiary treatment
Further treatment of refractory organic matter, nitrogen and phosphorus and other soluble inorganic matter that can lead to eutrophication of water bodies. The main methods are biological denitrification and phosphorus removal, coagulation sedimentation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis. The valves used are wafer butterfly valve, gate valve, ball valve, check valve, rubber soft joint, etc.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Video of center-lined butterfly valve: https://youtu.be/NuSZH_AJcwY
Video of triple eccentric butterfly valve: https://youtu.be/AkRwg2X1Wh0
Video of dual plate wafer check valve: https://youtu.be/XqRRI7o-LFI
Video of knife gate valve: https://youtu.be/vFSbTF_FGXM
Video of resilient seated gate valve: https://youtu.be/AI-LT1dy2sU

Structure of Triple Eccentric Metal seated Butterfly Valve (Picture)

December 31, 2021

Butterfly valves can be divided into soft-sealed butterfly valves and metal seated butterfly valves according to the sealing form. This article mainly analyzes the structure of the triple eccentric metal seated butterfly valve. Metal hard seal butterfly valves are usually used in some high temperature and high pressure environments. They are mainly composed of valve body, butterfly plate, valve shaft, valve seat, butterfly plate sealing ring, shaft sleeve, self-lubricating bearing, driving device and so on.

D943H-16C-metal seated stainless steel electric triple offset butterfly valve

The triple eccentric metal hard seal butterfly valve is a high-performance butterfly valve. It drives the rotation of the valve shaft through various driving devices, and the valve shaft drives the butterfly plate to rotate within the range of 0-90° in the valve body passage to achieve the valve opening and closing. The purpose is to realize the control of the medium flowing in the pipeline. Because of its super high performance, the triple eccentric metal hard seal butterfly valve can be widely used in the pipelines of generators, steam, hot and cold air, chemical smelting engineering, power generation, environmental protection, etc. The applicable media include various corrosive and non-corrosive fluid media. .

Structure diagram of triple eccentric metal seated butterfly valve
Insert “154-1 Picture”

Structural features of triple eccentric metal seated butterfly valve
①Unique and novel three-way eccentric design, frictionless transmission between sealing surfaces, greatly prolonged valve life.
②The elastic seal is produced by the torque, which improves the sealing performance of the valve.
③The wedge-shaped design allows the valve to be closed tighter and tighter, realizing automatic sealing, and the sealing surfaces directly compensate each other to achieve zero leakage.
④The drive mode of the valve can be selected according to the needs of customers, such as equipped with pneumatic and electric devices.
⑤ Only need to change the material of the parts, the valve can be applied to different media, and it can also be lining anti-corrosion (lining F46, GXPP, PO, etc.).
⑥The sealing ring is made of stainless steel, and it has the advantages of metal hard seal and elastic seal. It can achieve good sealing performance regardless of low temperature environment or high temperature working conditions.

If you want to know more about the triple eccentric metal seated butterfly valve, please pay more attention to the official website of “Tanghai Valve”. If you have any valve requirements in this area, you are also welcome to inquire.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Video of triple eccentric butterfly valve:

Application of double eccentric butterfly valve and triple eccentric butterfly valve

December 29, 2021

Butterfly valves can be divided into centerline butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves and triple eccentric butterfly valves. These butterfly valves are widely used in our production and life. Because of some defects of the centerline butterfly valve itself, it is not suitable for the environment where the temperature and pressure are too high or too low, so the butterfly valve is continuously improved, and this is the new design of single eccentric, double eccentric, and triple eccentric. Improvement is a breakthrough. Nowadays, the

Double eccentric-lug butterfly valve-D72F-150lbP-stainless steel (4)

application range of double eccentric butterfly valve and triple eccentric butterfly valve is wider and wider. This article will introduce the application of double eccentric butterfly valve and triple eccentric butterfly valve.

Application of double eccentric butterfly valve
The double eccentric butterfly valve is designed with eccentric structure and is widely used in the fluid pipeline system of water supply and drainage, sewage, construction, petroleum, chemical, textile, paper, hydropower, metallurgy, energy and other projects for regulation and interception.
Under normal circumstances, the seat material of the double eccentric butterfly valve is made of tetrafluoroethylene, which can effectively prevent corrosion. In addition, metal sealing seat can also be used to adapt to the high temperature environment. However, the double eccentric butterfly valve adopts metal sealing seat. The sealing surface of the butterfly plate and the seat is in line contact. The seal is a positional sealing structure. This sealing structure cannot withstand high pressure. If used in high pressure conditions, it will cause a lot of leakage. Therefore, do not use double eccentric butterfly valves with metal seal seats in high-pressure working environments or systems that require tight shut-off.

Application of triple eccentric butterfly valve

triple eccentric butterfly valve-lug

The triple eccentric butterfly valve is currently the most technologically advanced butterfly valve. It not only absorbs the advantages of other butterfly valve products, but also avoids the shortcomings of other butterfly valves, and has been valued by more and more users and technicians. The triple eccentric butterfly valve has a lot of leeway in the selection of sealing materials, and can deal with corrosive media such as high and low temperatures and various acids and alkalis. In addition, the triple eccentric butterfly valve can achieve zero leakage and is particularly suitable for making large-diameter valves. When used as a cut-off valve, it can replace gate valves and ball valves; when used as a flow adjustment, it can replace bulky shut-off valves.
At present, triple eccentric butterfly valves are used in important pipelines in large industrial fields such as petroleum exploration, petroleum refining, petrochemical, and energy power generation. As people continue to study, it is believed that triple eccentric butterfly valves will be applied to more and more fields.
If you want to know more about double eccentric butterfly valve and triple eccentric butterfly valve, please visit the official website of “Tanghai Valve”. If you have valve requirements in this area, you are also welcome to inquire and order.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D.
Video of center-lined butterfly valve: https://youtu.be/NuSZH_AJcwY
Video of double eccentric butterfly valve: https://youtu.be/yOw2xp3bIaE
Video of triple eccentric butterfly valve: https://youtu.be/AkRwg2X1Wh0

What is a triple eccentric metal seated butterfly valve

November 30, 2021

The triple eccentric metal seated butterfly valve is classified from the multi-level metal seated butterfly valve. Named because of the triple eccentricity structure. Its sealing performance is as good as the soft sealing butterfly valve, and it can maintain a good seal even in a high-pressure and high-temperature environment. It is often used for heating, gas, and gas, oil, acid and alkali environments, and appears in industrial pipelines such as petrochemical, food, medicine, textile, paper, electricity, sewage treatment, water supply and drainage, and smelting. A variety of gas, liquid, semi-fluid and micro-particle powder transportation pipelines or containers also play an important role. In more and more sites, it has gradually begun to replace electric gate valves and stop valves. And the installation position of the triple eccentric metal seated butterfly valve can be arbitrary, which is very convenient.

triple eccentric butterfly valve-wafer-lug-double flange-welded (5)

Let’s take a look at its structural characteristics and principle of action:
1. The difference between the triple eccentric metal seated butterfly valve and the ordinary butterfly valve is the triple eccentric design structure. The advantage of this structure is that there is less friction and no wear during the opening and closing process, which greatly extends the service life of the valve. The disc installation center and the rotation center are designed with a strict eccentricity.
2. The valve seat of this product is embedded with O-shaped rubber ring or fluorine plastic as the sealing gasket. This greatly compensates for the lack of tight sealing of the hard seal butterfly valve, while retaining the advantage of strong applicability of the hard seal. When the medium pressure is introduced into the sealing groove, the product seal squeezes the valve seat sealing surface to the butterfly plate under pressure to seal the valve. This unique sealing structure makes the greater the pressure, the stronger the sealing force.
3. The advantage of the triple eccentric metal seated butterfly valve is also reflected in the later maintenance. Once the sealing ring leaks, the valve can be fine-tuned to the required size by the adjusting screw to the direction of the butterfly plate without disassembling the valve, and the sealing performance of the new valve can be regained, which is a very valuable advantage.
4. In addition to the manual type, the product also has three categories and six series of products such as pneumatic and electric, which fully meets the needs of the site.
On the occasion of use, the triple eccentric metal seated butterfly valve is very suitable for working conditions where the temperature is high and leakage is not allowed, and the medium is impure and impurity, such as cement plants and power plants. And the sealing can be improved by surfacing the sealing surface and improving the strength of the valve seat. If the working conditions allow certain leakage, the ventilation butterfly valve is better to use. Tanghai Valve independently develops, produces and sells various butterfly valve products, including hard-sealed butterfly valves, flanged butterfly valves, electric butterfly valves, pneumatic butterfly valves, pipe network butterfly valves and many other products. Welcome to visit our factory.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Operation precautions of stainless steel butterfly valve

November 2, 2021

Stainless steel butterfly valves are usually metal seated butterfly valves, which can be driven by manual, pneumatic, etc., and are suitable for use in high temperature and corrosive medium pipelines. Stainless steel butterfly valves are currently widely used in the market and can be seen in many fields. Especially in metallurgy, chemical industry,

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

building materials, power stations, glass and other industries in the dusty cold or hot air pipelines of ventilation and environmental protection projects, it plays an important role as a gas medium to adjust the flow or cut off the device.

Stainless steel butterfly valves mainly have the following two characteristics:
1. It is designed and manufactured with a new structure welded by a centerline disc plate and a short structure steel plate. It is compact in structure, light in weight, easy to install, small in flow resistance, large in circulation, avoiding the influence of high temperature expansion, and easy to operate.
2. There are no connecting rods, bolts, etc., so it works reliably and has a long service life. It can be installed in multiple positions and is not affected by the flow direction of the medium.
The advantages and disadvantages of stainless steel butterfly valves are: advantages. 1. It is convenient and quick to open and close, labor-saving, low fluid resistance, and can be operated frequently. 2. Simple structure, small size and light weight. 3. Mud can be transported, and the accumulation of liquid at the pipe mouth is the least. 4. Under low pressure, good sealing can be achieved. 5. Good adjustment performance. shortcoming. 1. The working pressure and working temperature range are small. 2. Poor airtightness.
In view of these characteristics, we first strictly follow the operating procedures in the instructions in our usual operations. Finally, pay attention to observe the valve opening and closing instructions and the operation of the valve stem, and the valve opening and closing degree must meet the requirements. In the process of opening and closing the valve, if the signal indicator is found to be wrong or the valve makes an abnormal sound, it should be shut down in time for inspection. We pay attention to these problems in daily use, so as to reduce the damage caused by operating errors in stainless steel butterfly valves.
Stainless steel butterfly valve is one of the valve products that many manufacturers need to purchase. Customers must pay attention to the selection of valve manufacturers when choosing specific valve parameters such as model size and caliber. Only by choosing a reputable and advantageous valve manufacturer can the valve quality be better and the later repairs more convenient.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Application of metal seated butterfly valve in metallurgical field

October 28, 2021

In the initial use of metallurgical blast furnaces, gate valves occupies half of the country. However, as the government has increased its efforts in environmental protection construction, and the pipe diameter of the blast

D943H-16C-metal seated stainless steel electric triple offset butterfly valve

furnace system has gradually increased, the metal seated butterfly valve, which is light in weight, good in sealing performance, small in torque, and more suitable for making large-diameter valves, has gradually replaced gate valves. It is widely used in the field of metallurgy.
The metal hard seal butterfly valve has two driving methods: hydraulic drive and electric drive. In the ironmaking blast furnace, it is mainly installed in the waste heat utilization system, the dry dust removal system and the gas pipe network. It is used under the high temperature conditions of large nominal diameter, low working pressure and opening and closing pressure difference, and temperature of 200-350℃ . Because most of the metallurgical system pipelines are high-temperature gas media, the metal hard seal eccentric butterfly valve has been developed.
The metal hard sealing butterfly valve adopts surface-to-surface contact, and the sealing material is metal, so it is more resistant to high temperatures, even up to 400°C. However, correspondingly, the selection of metal seals has become very important. We must choose old brands and professional brands. Because brand manufacturers pay attention to reputation and their qualifications are relatively sound, we can check whether the metal seal is of high quality when purchasing, which can ensure that it maintains flexibility under high temperature conditions. This is also the possibility to ensure that the metal eccentric butterfly valve will not deform and leak after a period of use.
Now Tanghai also has a triple-eccentric butterfly valve whose sealing pair is a multi-layer composite material, which is a composite of metal and non-metal materials. This further makes up for the slight inferiority of metal sealing performance to fluorine lining, especially the non-metal interlayer in the middle can make the sealing of the sealing pair produce a stepped sealing form. After long-term use, it can still maintain good and reliable high-temperature use effects. The disadvantage is that the valve can maintain good sealing performance while maintaining high temperature and aging resistance. Various systems in metallurgical blast furnaces have been widely used, especially high-temperature systems.
Metal hard seal butterfly valves are suitable for high temperature gas pipeline systems in metallurgy, mining, cement, chemical, power generation and urban heating industries, as opening and closing equipment. In addition, Tanghai’s metal eccentric hard seal butterfly valve has compact structure, few parts, small size, light weight, high temperature resistance, flexible opening and closing, and can achieve zero leakage under long-term working conditions, long service life, and low power required. , The future will also usher in a wider range of applications.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

How to choose concentric |double eccentric |triple eccentric butterfly valve

October 26, 2021

The difference in butterfly valve structure distinguishes four types of butterfly valves, namely: concentric butterfly valve, single eccentric butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve. What is the concept of this eccentricity? How to decide when to use concentric butterfly valve, when to use single eccentric

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

butterfly valve, when to use double eccentric butterfly valve and triple eccentric butterfly valve? Many users are not particularly clear. We might as well share together.
Concentric butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves and triple eccentric butterfly valves reflect the process of opening and closing more and more labor-saving, and the sealing surface wear is getting smaller and smaller. By setting the position of the shaft of the butterfly valve valve plate, the sealing and opening state of the butterfly valve can be changed. Under the same conditions, the torque of the valve is greater than one at each opening. When the valve is opened, the angle required for the valve plate to be separated from the seal is smaller than one.
The structural feature of the concentric butterfly valve is that the shaft center of the valve stem, the center of the butterfly plate, and the center of the valve body are in the same position. Generally, if you can use concentric butterfly valves in principle, use concentric butterfly valves as much as possible. Because the concentric butterfly valve does not require high sealing performance in terms of structure or operation, it is a conventional product. In order to overcome squeezing, scratching, and to ensure the sealing performance, the seat of the concentric butterfly valve is basically made of rubber or polytetrafluoroethylene and other elastic materials,

Double eccentric-wafer butterfly valve-D372F-150lbP-stainless steel (1)

which is a soft sealing butterfly valve. This makes the concentric butterfly valve subject to temperature restrictions in use. In order to solve the problem of the squeezing of the butterfly plate and the valve seat of the concentric butterfly valve, a single eccentric butterfly valve was also produced. Its structural feature is that the shaft center of the valve stem deviates from the center of the butterfly plate.
Double eccentric butterfly valve is the most widely used. Its structural feature is that the shaft center of the valve stem deviates from the center of the butterfly plate and the center of the valve body. It deviates from the two center positions so it is called a double eccentric butterfly valve. Many double eccentric butterfly valves are line-sealed. When the sealing surface is closed, friction occurs between the disc and the valve seat, and the sealing effect is very good. It has the characteristics of small area and strong pressure. After the valve is opened, the butterfly plate can be quickly separated from the valve seat, which greatly eliminates unnecessary excessive squeezing and scratching of the butterfly plate and the valve seat, reduces the opening resistance, reduces the wear, and improves the life of the valve seat.
The triple eccentric butterfly valve is eccentric for the third time on the basis of the double eccentric butterfly valve. The shape of the sealing pair is not a positive cone, but an oblique cone. Mostly short-distance force and face seal. The stem shaft of the triple eccentric butterfly valve is a three-section shaft structure. The two shaft sections of this three-section shaft valve stem are concentric, and the center line of the central section shaft deviates from the axis of both ends by a center distance, and the butterfly plate is installed in the middle On the shaft section. Such an

U-type flange butterfly valve, ductile iron, DI, center line,

eccentric structure makes the butterfly plate a double eccentric shape when in the fully open position, and a single eccentric shape when the butterfly plate rotates to the closed position. Due to the effect of the eccentric shaft, when it is close to closing, the butterfly plate moves a distance into the sealing cone surface of the valve seat, and the butterfly plate matches the sealing surface of the valve seat to achieve reliable sealing performance. It makes up for the contradiction that the hard seal has poor sealing, and the soft seal has good sealing effect but is not resistant to high temperatures. When to use a concentric butterfly valve and when to choose a double eccentric butterfly valve or a triple eccentric butterfly valve, it mainly depends on the usage habits and budget. If it is not for extreme working conditions, concentric butterfly valves can generally be selected, and concentric butterfly valves should be used as much as possible. Because the concentric butterfly valve is simple in structure and relatively economical in price.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Features of Stainless Steel Valves

September 15, 2021

Generally speaking, stainless steel valves are valves made of stainless steel. They are classified according to the stainless steel material grade of the valve body. They are mainly 301, 304, 316, 304L, 316L, etc. According to international standards, they can be divided into CF8, CF3, CF8M, CF3M, the quality of the material

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

CF8<CF3<CF8M<CF3M. Because stainless steel has strong corrosion resistance, is easy to form, has high compatibility, and can remain strong in a wide temperature range, many advantages make stainless steel valves widely used in heavy industry, light industry, daily necessities industry and architectural decoration industry. middle.
Stainless steel refers to steel that is resistant to corrosion by weak corrosive media such as air, steam, water and chemical corrosive media such as acids, alkalis, and salts. It is also called stainless acid-resistant steel. Stainless steel valves are also stainless acid-resistant steel valves. , And resistant to acid and alkali corrosion. Research tests have shown that the corrosion resistance of steel in weak media such as the atmosphere and water and oxidizing media such as nitric acid will increase with the increase of the chromium water content in the steel. When the chromium content reaches a certain percentage, the corrosion resistance of steel The sex changes, that is, from easy to rust to not easy to rust, from no corrosion resistance to corrosion resistance.
Common stainless steel valves mainly include stainless steel butterfly valves and stainless steel ball valves. The gate valve is rarely made of stainless steel, because the gate valve is usually used for low corrosive media such as water.
Stainless steel butterfly valve, also known as stainless steel flap valve, usually adopts three-eccentric metal hard sealing structure. The valve body, valve seat and butterfly plate sealing surface are all made of stainless steel with different hardness, which has strong corrosion resistance and long service life. It is widely used in metallurgical, electric power, petrochemical, water supply and drainage, municipal construction and other industrial pipelines with fluid pipeline medium temperature ≤ 425°C.
Stainless steel ball valves usually require horizontal installation in the pipeline. Stainless steel ball valves can be divided into stainless steel pneumatic ball valves, stainless steel electric ball valves, and stainless steel manual ball valves according to the driving mode. According to different stainless steel materials, it is divided into 304, 316, 321 stainless steel ball valves. The stainless steel ball valve switch is light and can also be made into a large diameter. It has reliable sealing, simple structure and convenient maintenance. The sealing surface and spherical surface are often in a closed state and are not easily eroded by the medium. It has applications in various industries.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

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