triple-eccentric Archives

Structure diagram of triple eccentric butterfly valve

March 24, 2022

With the advancement of science and technology and the improvement of production technology, the industrial requirements for butterfly valves are no longer simple cut-off and adjustment of normal temperature and low pressure media, but also require butterfly valves to play a role in high temperature and high pressure environments. For this reason, the triple eccentric butterfly valve was born, and has replaced the application of some gate valves, globe valves, ball valves and other valves in the industry. What is the structure of the triple eccentric butterfly valve? What are the structural characteristics of the triple eccentric butterfly valve?

Triple eccentric butterfly valve structure

triple eccentric butterfly valve structure diagram

The triple eccentric butterfly valve is a hard-sealed butterfly valve. This kind of butterfly valve adopts the triple eccentric sealing structure and has the characteristics of compact structure, fast opening and closing speed, labor-saving and light operation, and reliable sealing performance. It is suitable for pipelines under various working conditions. media flow. Three eccentric butterfly valves are currently widely used in electric power, metallurgy, petroleum, chemical industry, urban heating and other industries.

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

1. The shape of the sealing surface of the valve body and the butterfly plate is an elliptical cone, and the center line of the sealing cone surface of the valve body and the butterfly plate has an eccentric angle c° with the center line of the valve body channel.
2. There is an axial eccentricity a between the center line of the valve body and the disc sealing surface and the valve stem shaft.
3. There is a radial eccentricity b between the center line of the valve stem and the center line of the valve body.

Triple eccentric butterfly valve sealing principle
On the basis of the double eccentric sealing butterfly valve, the center line of the valve seat and the center line of the valve body form a β angle offset. When the triple eccentric sealing butterfly valve is in a fully open state, the sealing surface of the valve plate will be completely separated from the sealing surface of the valve seat. , and the same gap y as the double eccentric sealing butterfly valve is formed between the sealing surface of the valve plate and the sealing surface of the valve seat. When the valve plate of this type of butterfly valve is opened from 0° to 90°, the sealing surface of the valve plate will be separated from the sealing surface of the valve seat at the moment of opening. When it is closed at 90° to 0°, only at the moment of closing, the sealing surface of the valve plate will contact and press the sealing surface of the valve seat.

This is the three eccentricities of the triple eccentric butterfly valve. So what are the characteristics of the triple eccentric butterfly valve structure?
1. The unique triple eccentric design, the friction coefficient between the valve body and the sealing surface of the disc is extremely small, which reduces the wear of the sealing surface and prolongs the service life of the valve.
2. The eccentric design reduces the opening and closing torque of the valve, and the opening and closing is more rapid.
3. The valve body and the disc are directly conical, as shown in the figure above, when the disc is closed, the medium exerts pressure on the disc. The conical design makes the valve more tightly closed, realizing automatic sealing and greatly improving Improve the sealing performance and truly achieve zero leakage.
4. It can be equipped with different driving methods according to customer needs or working conditions, such as installing pneumatic and electric actuators to realize automatic operation of triple eccentric butterfly valves.
5. The sealing ring on the butterfly plate is made of stainless steel sheet and flexible graphite. It has the rigidity of metal and the elasticity of non-metal, and also makes the triple eccentric butterfly valve have the advantages of metal hard sealing and elastic sealing at the same time. Good sealing performance can be achieved in low temperature environment or high temperature working condition.

If you want to know more about triple eccentric metal hard sealing butterfly valve, please pay more attention to the official website of “Tanghai Valve”. If you have the needs of this valve, 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:

Properties of triple eccentric butterfly valve

February 10, 2022

Performance advantages of triple eccentric butterfly valve:
1. It integrates adjustment and cut-off, and has strong controllability.
The design of the new triple eccentric butterfly valve adopts a double safety structure. In order to prevent the deformation of the disc, the dislocation of the valve stem, and the occlusion of the sealing surface caused by the

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

influence of fluid pressure and temperature, two independent stoppers are installed on the upper and lower sides of the disc. The push ring ensures the normal operation of the valve under any working conditions; in order to prevent the valve stem from being damaged and flying out and causing unexpected accidents, independent valve stem flying-out prevention mechanisms are designed at the lower end of the valve inside and outside.
2. No dead zone design, small opening torque.
The shape of the valve plate of the triple eccentric butterfly valve is an elliptical cone, and its surface is surfacing with hard alloy, which has excellent wear resistance. The floating U-shaped stainless steel valve seat has the function of automatically adjusting the center. When the valve is opened, the valve plate of the elliptical cone sealing surface is first separated from the U-shaped elastic valve seat, and then rotated; when the valve is closed, the valve plate rotates, and the valve plate automatically adjusts the center to the elastic valve seat under the action of the eccentric shaft. Seat pressure deforms the seat until the seat is in close contact with the oval conical sealing surface of the valve plate. When the valve is switched on and off, the disc does not scratch the valve seat, the torque of the valve stem is directly transmitted to the sealing surface through the disc, and the opening torque is small, thus eliminating the common jumping phenomenon when opening the valve, that is, eradicating the dead zone (no sense band) . This design without dead zone enables the triple eccentric butterfly valve to enter the controllable area almost from 0 opening to 90 opening, and its control ratio can be as high as 1001 or more, which is twice that of ordinary butterfly valves.
3. Zero leakage, high temperature and high pressure resistance.
The biggest feature of triple eccentricity is that it fundamentally changes the sealing structure. It is no longer a position seal, but a torsion seal, that is, it does not rely on the elastic deformation of the valve seat, but completely relies on the contact surface pressure of the valve seat to achieve the sealing effect. This sealing structure enables the triple eccentric butterfly valve to achieve a hard seal of level VI and achieve true zero leakage. At the same time, due to the selection of the metal valve seat and the structural characteristics of the face seal, the problem of high temperature and high pressure resistance is also easily solved. In addition, the triple eccentric butterfly valve adopts the body seat structure, which makes the valve structure more compact, and reduces the chance of the valve seat directly contacting the medium, reduces the degree of erosion of the valve seat, and can effectively prevent small solids in the medium. The impact of the material and thermal expansion may cause the sealing surface to bite, thereby extending the service life of the valve seat. The new triple eccentric butterfly valve can not only replace the body seat, but also the disc sealing surface and disc are independent, and the disc sealing surface can also be replaced, which greatly reduces the maintenance cost.

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:

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

Evolution of the Sealing Surface of the Triple Eccentric Butterfly Valve

December 9, 2021

The triple eccentric butterfly valve is one of the butterfly valves. Its unique sealing form and sealing structure are continuously improved and upgraded through the product to obtain a better sealing effect. There have been great reforms in high temperature and corrosion resistance. Let’s take a look at its product upgrade process.

triple offset butterfly valve-double flange- (5)

The butterfly valve’s single eccentric soft-seal butterfly valve is the first to be favored by the market. Because of the design of the soft seal, the product has a good sealing effect. Single eccentricity means that the sealing section of the valve seat is eccentric relative to the center of rotation of the valve stem, so that the sealing surface of the butterfly plate gradually separates from the sealing surface of the valve seat during the opening process. When the butterfly plate rotates to 20-25, the sealing surface of the butterfly plate is completely separated from the sealing surface of the valve seat, so that the relative mechanical wear and extrusion between the two sealing surfaces of the butterfly valve is greatly reduced during the opening process, and the sealing performance of the butterfly valve is improved. This design mainly relies on the elastic deformation of the squeezing between the butterfly plate and the valve seat to ensure the sealing of the butterfly valve.
In order to meet the needs of the site, to achieve the effect that the sealing surface of the butterfly plate is separated from the sealing surface of the valve seat faster than the single eccentric structure, the double eccentric sealing butterfly valve is upgraded on the basis of the single eccentric butterfly valve. The lines are relatively offset, so that the butterfly valve forms a cam effect during the opening process. When the butterfly plate rotates to 8°~12°, the two sealing surfaces can be completely separated. The biggest benefit of this structural design is to further reduce the mechanical wear and extrusion deformation between the two sealing surfaces, which improves the sealing performance of the butterfly valve and increases the lifespan.
The triple eccentric sealing butterfly valve is once again upgraded on the basis of the double eccentric butterfly valve. The center line of the seat sealing surface and the valve center line form an angular eccentricity, and a third eccentricity appears. In this way, during the opening process, the sealing surface of the butterfly plate can be separated from the sealing surface of the valve seat immediately, and will contact and compress the sealing surface of the valve seat at the moment of closing. This unique eccentric design makes full use of the benefits of the cam, so that the mechanical friction and scratches between the two sealing surfaces of the butterfly valve seal pair can be completely eliminated when opening and closing, so that the possibility of wear and leakage is eliminated. The product changes the extrusion seal into a torque seal. By adjusting the external driving torque, the adjustment of the seal specific pressure is realized, so that the sealing performance and service life of the triple eccentric structure sealing butterfly valve are greatly improved. At the same time, while ensuring a tight seal, it also improves the characteristics of the sealing sub-materials of the single-eccentric soft-seal butterfly valve and the double-eccentric soft-seal butterfly valve that cannot withstand high temperature and wear.
Now, the triple eccentric sealing butterfly valve is widely used as the best device to cut off or adjust the flow of the medium pipeline in the urban construction, petrochemical, metallurgy, electric power and other industries. Its structure itself is the most ideal opening and closing part in pipelines, and it is the development direction of today’s pipeline opening and closing parts. If you need butterfly valve products, look for Tanghai Valve. 24 years of experience in butterfly valve production is more assured.

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: https://youtu.be/AkRwg2X1Wh0

Two-way triple eccentric butterfly valve

December 8, 2021

The two-way hard-sealed butterfly valve is a valve product that has been developed rapidly in recent years. From the earliest centerline butterfly valve to the later triple eccentric sealing butterfly valve to the current triple eccentric two-way sealing structure, the hard sealing butterfly valve has greatly reformed and improved its own sealing performance. In the course of this evolution and development, leading valve manufacturers have paid tremendous hard work and efforts.

cryogenic triple offset butterfly valve 1

Let’s first take a look at the sealing characteristics of the two-way hard-sealed butterfly valve. Its sealing material is forged with metal or materials with strong hardness. It has strong durability and longer service life than ordinary valve products. However, because of the material characteristics of the sealing surface, the sealing performance is worse than that of ordinary butterfly valves. Make it completely sealed. But now, with the improvement of technology, there have been the emergence of multi-layer hard sealing butterfly valves, which can achieve zero leakage and have the dual advantages of soft and hard sealing.
The seat sealing surface of the two-way hard sealing butterfly valve adopts alloy material butt welding form, high temperature resistance, easy to operate, and the opening and closing torque is transmitted to the valve stem without friction, which greatly improves the sealing performance of the sealed butterfly valve and prolongs its service life. Its main technical feature is the advantages of sealing two-way. This structure effectively compensates for the pressure of the medium, and can achieve zero-leakage sealing performance regardless of whether it is at low temperature or high temperature.
Science and technology are developing, and society is also progressing. In the past ten years of development, the two-way hard seal butterfly valve has made great progress in product development, performance, quality, reliability, and service. The market prospects are optimistic. In the future, valve manufacturers will also make greater efforts to continuously innovate and formulate development paths in terms of electricity, water, and materials. Speed up the elimination of low-efficiency and high-energy-consuming butterfly valve products, adjust the industrial structure, and promote the development and promotion of new technologies and products. At present, some long-established manufacturers already have their own multi-system butterfly valve products. If you want to purchase two-way hard-sealed butterfly valves, Tanghai Valve is your first choice.

Compared with ordinary butterfly valves, the two-way hard-to-hard seal butterfly valve has the biggest difference in that it does not require the installation direction, that is, the direction of its input and output is uncertain. Ordinary butterfly valves are one-way and have restrictions on the installation direction. In addition to this, there is another point to pay attention to when installing the two-way hard-to-hard seal butterfly valve, that is, it cannot be installed and used in places with too much pressure.
Why can’t the two-way hard-to-hard sealing butterfly valve be used in places with too much pressure? Now let’s take a look at the reasons:
1. Because the valve plate is in a normally open state, the sealing ring fixed on the valve plate is multi-layered, that is, multi-layer soft and hard stacked sealing ring. In the normally open state, the medium will flush its sealing surface positively. If the pressure is too high, the soft sealing tape in the metal sheet sandwich will be easily washed away and cause leakage.
2. At the same time, because the overall structure of the valve plate of the two-way hard-to-hard seal butterfly valve is generally thicker, the flow resistance is also relatively large. If it is installed in a place with high pressure, the flow resistance and friction can be imagined, and the damage to the sealing surface will be great.
3. Because this product is a two-way seal, the product seal is mainly to press the valve plate against the valve seat through the torque of the transmission device. The greater the pressure, the tighter the seal, but it should be in a positive flow state at this time. But if the medium in the flow channel flows backwards, if it is installed in a pipeline position with too much pressure, it is easy to cause the positive pressure of the seal between the valve plate and the valve seat to be less than the medium pressure, and leakage will occur.
The two-way hard-to-hard sealing butterfly valve has many advantages, including: it is not hindered by forward pressure and reverse pressure, and can be reliably shut off; the two sealing surface materials of the sealing pair can choose different functional materials according to different hardness; there is automatic The centering function can automatically overtravel to compensate for wear. In addition, a series of advantages such as small size, light weight, convenient transportation, installation, maintenance and repair, and reliable operation make the two-way hard-to-hard seal butterfly valve more and more popular in the market. If you have relevant needs, please consult Tanghai Valve and choose your suitable valve product.

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: 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

How to replace valve packing for triple eccentric sealing butterfly valve

November 19, 2021

Although we are not focusing on valve packing during the procurement and use of triple eccentric butterfly valves, in fact packing has a great influence on the service life of the valve. If we find that the upper cavity is leaking during the pressure test, it is likely to be caused by the leakage of the packing. Wrong type of packing, packing leakage will cause internal leakage and greatly affect the service life.

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

There are many reasons for packing leakage. For example, the packing is the sealing effect of the pressure of the gland in the valve. After operation, the packing will age and become hard, especially the frequently used triple eccentric sealing butterfly valve, the friction between the valve stem and the packing is reduced, and it is easy to leak water and steam. At this time, the valve packing needs to be replaced. In normal times, we also need to regularly replace the valve packing through the investigation. Let’s take a look at how to replace the valve packing.
When replacing the packing for the triple eccentric sealing butterfly valve, for small valves with gland nuts, you can use a wire hook to clean the packing, put the asbestos rope clockwise around the valve stem and re-install the packing surface, and then tighten the gland nut. . Do not use excessive force when installing the nut to prevent tripping or breakage. If it still leaks after replacement, tighten it again until it does not leak. For large valves with flange glands, square or round asbestos ropes braided into strands can be cut into small sections according to the required length and laminated, and the joints of each layer should be staggered by 180°. When tightening the gland, the bolts on both sides should be compressed alternately to prevent the gland from breaking due to uneven force, and the rotation of the valve skewer should be checked to ensure the flexible rotation of the valve stem.
It is important to mention here that many developed countries do not allow the use of asbestos-containing valves. This is because asbestos has slight carcinogens, so triple-eccentric sealing butterfly valves with asbestos plates on the sealing surface are firmly not allowed to be used in drinking water. It can be considered to use full graphite or 314 or tetrafluoroethylene instead.
The triple eccentric sealing butterfly valve is widely applicable and easy to use. It has the advantage that it can be applied to a variety of working conditions by replacing the sealing pair, which is very popular. Need triple eccentric sealing butterfly valve, welcome to consult the brand manufacturer Tanghai Valve, who has rich experience in the production and processing of butterfly valve products, and there are many cases. I believe you will find your favorite products here.

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

Precautions for the use of triple eccentric metal seated butterfly valve

November 16, 2021

Triple eccentric hard-sealed butterfly valves are generally metal seated butterfly valves, which have an eccentric metal sealing structure. Sealing forms include metal-to-metal sealing, stainless steel plate and graphite composite plate sealing ring to metal sealing, etc. The driving methods are mainly electric, manual, turbo rod transmission,

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

pneumatic and so on. The triple eccentric hard-seal butterfly valve is very popular in the market. It maintains the advantages of the centerline butterfly valve and discards the disadvantage of the poor sealing performance of the metal seal. It is a more promising product in the market. Let’s take a look at the problems we need to pay attention to in use:
1. The triple eccentric hard sealing butterfly valve is a multi-layer soft and hard stacked sealing ring, which is also a very significant feature of the triple eccentric hard sealing butterfly valve. The seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of the soft T-shaped sealing ring. When the valve plate is in the normally open state, the medium will form a positive scouring on its sealing surface, and the soft sealing tape in the metal sheet sandwich will directly affect the sealing performance after being scoured.
2. The valve will be restricted by the structural conditions, so the structure is not suitable for valves with a diameter below DN200, because the overall structure of the valve plate will be too thick and the flow resistance will be large.
3. The principle of the valve’s triple eccentric structure. The sealing between the sealing surface of the valve plate and the valve seat is to press the valve plate against the valve seat by the torque of the transmission device. It is a self-sealing property. That is, when the medium is flowing in the forward direction, the higher the medium pressure, the tighter the sealing and squeezing. However, in general, when the flow channel medium flows back, as the medium pressure increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the seal will begin to leak.
Is there a solution to the inability to achieve two-way sealing? Butterfly valve manufacturers add an adjustment ring between the pressure plate and the valve seat to achieve a very ideal two-way hard seal. The sealing surface of the valve plate and the valve seat of the triple eccentric sealing butterfly valve is an oblique cone structure, and temperature-resistant and corrosion-resistant alloy materials are surfacing welded on the oblique cone surface of the valve plate. A structure in which the spring fixed between the pressure plate of the adjusting ring and the adjusting bolt of the pressure plate are assembled together. This structure effectively compensates for the tolerance zone between the shaft sleeve and the valve body and the elastic deformation of the valve stem under the medium pressure, and solves the sealing problem of the valve in the two-way interchangeable medium conveying process.
When the medium flows backward, the seal between the valve plate and the valve seat depends on the torque of the driving device to press the valve plate against the valve seat. With the increase of the reverse medium pressure, when the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the deformation energy stored by the spring of the adjusting ring after being loaded compensates for the tight pressure of the sealing surface of the valve plate and the valve seat Play the role of automatic compensation.
The triple eccentric hard seal butterfly valve adopts a soft T-shaped multi-layer stainless steel sheet on both sides to form a sealing ring. It has the dual advantages of metal hard and soft sealing, and has zero leakage sealing performance regardless of low temperature and high temperature. In the future, it may also replace gate valves and ball valves.

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

Advantages of Triple Eccentric Metal seated Butterfly Valve

September 26, 2021

The triple eccentric butterfly valve belongs to the metal seated butterfly valve. The triple eccentricity is named because its stem axis deviates from the center of the disc and the center of the body at the same time, and there is a certain angle between the axis of rotation of the valve seat and the axis of the valve body channel. The triple-eccentric butterfly valve is corrosion-resistant, wear-resistant, and has a long service life. It is suitable for working conditions

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

where the medium temperature is ≤425℃. It is widely used in metallurgy, electric power, petrochemical, and water supply and drainage, municipal construction and other industrial pipelines for adjustment. Flow rate and use of off-load fluid. The body materials of the triple eccentric butterfly valve are cast iron, cast steel and stainless steel. This article will make an analysis and introduction to the advantages of the triple eccentric butterfly valve.

1. The metal-to-metal elastic hard seal structure is a structure in which an elastic metal J-ring is installed on the valve seat. The J-ring is pressed by a pressure plate and fixed with bolts. The two sides of the J-ring are respectively provided with sealing rings with good sealing performance, high temperature and high pressure resistance, and a certain margin. The position of the J-ring can be adjusted to make the valve After a period of use, it will not leak due to wear. The valve is suitable for medium and high temperature and medium and high pressure pipeline systems.

2. High wear-resistant self-lubricating composite bearings are used in the key parts of the relative movement of the shaft and the body to reduce the friction of the butterfly plate when it is opened or closed, and to ensure that there is no wear between the shaft and the body.

3. At the bottom of the lower shaft of the valve body, a high-hardness wear-resistant alloy spherical thrust pad and a high-hardness flat pad are used. During the movement of the butterfly plate, all downward gravity and friction forces are concentrated here. Due to the high hardness of the two thrust pads, the small contact area, long-term movement without abrasion, to ensure that the valve opens and closes easily, and never sinks.

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

4. The triple eccentric structure is a qualitative leap of the butterfly valve. Therefore, the valve greatly improves the service life and significantly improves the opening and closing torque. If you don’t understand the triple eccentric structure, you can click (https://www.tanghaivalve.com/triple-eccentric-butterfly-valve-th-btv-te/) to view.

5. The metal-to-metal multi-layer composite hard seal structure is a structure in which a multi-layer composite metal ring is installed on the valve plate. The multi-layer composite metal ring is made of stainless steel metal plates and flexible graphite sheets repeatedly laminated and pressed, which has high strength and rigidity. Flexible graphite still has good sealing performance under high temperature and high pressure. The combination of rigidity and flexibility of these two materials makes the valve suitable for most media, with a wide range of applications and long service life.

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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