double eccentric butterfly valve Archives

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

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

Advantages and disadvantages of butterfly valve and structure diagram

July 26, 2021

Advantages and disadvantages of butterfly valve and structure diagram
The butterfly valve opening and closing part is a disc-shaped butterfly plate, which rotates around its own axis in the valve body to achieve opening and closing or adjustment. The butterfly valve is usually less than 900 from fully open to fully closed. The butterfly valve and the butterfly rod themselves are not self-locking. For the positioning of the butterfly plate, a worm gear reducer must be installed on the valve rod. The use of worm gear reducer can not only make the disc plate have self-locking ability, make the disc plate stop at any position, but also improve the operation performance of the valve.

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

The industrial butterfly valve is characterized by high temperature resistance, high applicable pressure range, large nominal diameter of the valve, the valve body is made of carbon steel, and the sealing ring of the valve plate uses a metal ring instead of a rubber ring. The large high temperature butterfly valve is made of steel plate welding, and is mainly used for flue ducts and gas pipes of high temperature media.
(1) Advantages of butterfly valve:
1. It is convenient and quick to open and close, labor-saving, low fluid resistance, and can be operated frequently.

Wafer and Lug type butterfly valve structures & parts

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.
(2) Disadvantages of butterfly valves:
1. The working pressure and working temperature range are small.
2. Poor airtightness.
(3) Installation and maintenance of butterfly valve:
1. During installation, the valve disc should be stopped in the closed position.
2. The opening position should be determined according to the rotation angle of the butterfly plate.
3. For the butterfly valve with bypass valve, the bypass valve should be opened before opening.
4. The installation should be carried out according to the installation instructions of the manufacturer, and the heavy-weight butterfly valve should be installed with a firm foundation.
Related knowledge: the principle of butterfly valve structure

Double flange butterfly valve structure

Related products: Electric butterfly valve Pneumatic butterfly valve

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

Selection and application of eccentric butterfly valve

June 23, 2021

Selection and application of eccentric butterfly valve
The advantages of eccentric butterfly valves and other butterfly valves are very prominent, so they are widely used in all aspects of life and work to meet various requirements. Moreover, with the continuous development of eccentric sealing butterfly valve technology, the space for its use becomes more and more extensive. TH valve company can produce double eccentric butterfly valve and triple eccentric butterfly valves, with good quality and reasonable prices.

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

Application of double eccentric sealing butterfly valve
The double eccentric sealing butterfly valve adopts an eccentric structure design. The main structure of the valve is composed of valve body, butterfly plate, valve seat, valve stem and transmission mechanism. The valve seat adopts a detachable structure and can be based on the physical and chemical properties of different media. Corresponding corrosion-resistant, light-resistant, and aging-resistant materials are selected, which can be widely used in fluid pipelines such as water supply and drainage, sewage, construction, air conditioning, petroleum, chemical, food, medicine, textile, papermaking, hydropower, shipbuilding, metallurgy, energy systems, etc. Used as a regulating and intercepting device. The double eccentric butterfly valve usually uses tetrafluoroethylene material as its sealing seat, and can also use metal sealing seat to expand its application in the high temperature field. However, the seal of the double eccentric butterfly valve with metal sealing seat is still a positional sealing structure, that is, the sealing surface of the butterfly plate and the seat is in line contact, so it cannot withstand high pressure, and it will inevitably lead to greater leakage when used in a high pressure system. Therefore, double eccentric butterfly valves with metal seal seats should be avoided as far as possible in high-pressure or tight shut-off systems.

Application of triple eccentric sealing butterfly valve
The triple eccentric butterfly valve, as the crystallization of the latest technology of valves, takes advantage of the advantages of various valves and avoids the shortcomings of various valves, and has attracted more and more

cryogenic triple offset butterfly valve 1

attention from users and designers. The maximum pressure level can reach 2500 pounds, the standard caliber can reach 48 inches, and the clamp, lug, flange, ring connection, butt welding, jacket, various structural lengths, etc. can be corresponded, due to the room for material selection Very large, high and low temperature, various acids, alkalis and other corrosive media can also respond freely. Especially in the aspect of large diameter, with its zero leakage advantage, it is constantly replacing the thick gate valve and ball valve in the shut-off valve. Similarly, with its excellent control function, it is also constantly replacing the bulky control valve. Shut-off valve. So far, triple eccentric sealing butterfly valves have been used in various important pipelines including China’s oil and gas exploration, offshore platforms, petroleum refining, petrochemicals, inorganic chemicals, energy power generation and other major industrial fields such as process control. In actual engineering, if the working pressure of the system is not less than 1.0 MPa or in important parts that need to be opened frequently, triple eccentric butterfly valves can be used.
Related knowledge: common sense of eccentric butterfly valve
Related products: Electric triple eccentric butterfly valve Pneumatic triple eccentric butterfly valve

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

Installation instructions of double eccentric butterfly valve

July 24, 2020

Installation instructions of double eccentric butterfly valve:
1. Before installation, you must carefully check whether the valve’s mark and certificate of conformity meet the requirements for use, and clean it after verification.

Double eccentric-wafer butterfly valve-D72F-150lbP-stainless steel (3)

Uninstalled valves should be stored in a dry room. Valves stored for a long time should be cleaned regularly, dried and coated with anti-rust oil. Blind plates shall be used to protect the flange sealing surface at both ends of the valve.
2. Install according to the flow direction of the medium; horizontal installation is preferred.
3. The connecting bolts of the butterfly valve and the pipeline should be tightened several times in the diagonal direction during installation, and no single piece should be tightened at a time to prevent the flange connection from leaking due to uneven force.
4. When installing the butterfly valve, the butterfly plate should be in the closed position to prevent debris from entering the valve cavity and scratching the sealing surface. When the user wants to test the pressure, be sure to install the flange pair on both ends and test the pressure.
5. When connecting the valve to the pipeline, it is required to use butt-welded steel flanges or special butterfly valve flanges on the pipeline. If flat-welded steel flanges are used, the inner hole of the flange must be the same size as the inner hole of the gasket to ensure the effective sealing surface of the gasket.
6. When the electric butterfly valve leaves the factory, the opening and closing stroke of the control mechanism has been adjusted. In order to prevent the direction from being wrong when the power is turned on, the user must manually move to 1/3 of the closed position before turning on the power for the first time. And check whether the direction of the indicator plate is consistent with the opening direction of the valve.
7. When the valve is in use, if any malfunction is found, stop using it immediately

Tanghai Valve is the best manufacturer of double eccentric butterfly valve in China. We produce the best quality products with competitive low prices. Main products: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

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 and application area of double eccentric butterfly valve

July 24, 2020

Double eccentric butterfly valve is also called high-performance butterfly valve. It is mainly used for drainage of water plants, power plants, steel smelting, chemical

5 double-eccentric-butterfly-valve-2

industry, water source engineering, environmental facility construction, etc. It is especially suitable for water pipelines and used as regulation and interception equipment. Compared with the centerline butterfly valve, the double eccentric butterfly valve is more resistant to high pressure, has a longer life and good stability.
Another name: high performance butterfly valve
Applicable area: water plant, power plant, steel mill smelting, chemical industry
Features: Longer life and good stability

use of double eccentric butterfly valve:
Double eccentric butterfly valve is also called high-performance butterfly valve. It is mainly used for drainage of water plants, power plants, steel smelting, chemical industry, water source engineering, environmental facility construction, etc. It is especially suitable for water pipelines and used as regulation and interception equipment. Compared with the centerline butterfly valve, the double eccentric butterfly valve is more resistant to high pressure, has a longer life and good stability. Compared with other valves, the larger the caliber, the lighter the material, and the lower the cost. But because there is a butterfly plate in the middle and the flow resistance is large, a butterfly valve smaller than DN200 is meaningless.

working principle of double eccentric butterfly valve:
The double eccentric butterfly valve is further improved on the basis of the single eccentric butterfly valve. Its structural feature is that the axis of the valve stem deviates from the center of the butterfly plate and the center of the body. The double eccentric effect enables the butterfly plate to be released from the valve seat immediately after the valve is opened, which greatly eliminates unnecessary excessive extrusion and scratching of the butterfly plate and the valve seat, reduces the opening resistance, reduces wear and improves The life of the valve seat is improved. The scraping is greatly reduced, and at the same time, the double eccentric butterfly valve can also use a metal seat, which improves the application of the butterfly valve in the high temperature field.

Structural features
1 Reasonable design, compact structure, easy assembly and disassembly, and easy maintenance.
2 The eccentric structure is adopted to reduce the friction of the sealing ring and prolong the service life of the valve.
3 Completely sealed, zero leakage. Can be used in ultra-high vacuum conditions
4 Replace the valve plate sealing ring, butterfly plate, shaft and other materials, which can be applied to a variety of media and different temperatures

Posts

Application of double eccentric butterfly valve and triple eccentric butterfly valve

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

Advantages and disadvantages of butterfly valve and structure diagram

Selection and application of eccentric butterfly valve

Installation instructions of double eccentric butterfly valve

Features and application area of double eccentric butterfly valve

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Double eccentric High performance butterfly valve (TH-BTV-DE)

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