butterfly valve factory Archives

Wafer Concentric Type Butterfly Valve (tanghai valve)

April 11, 2024

A wafer concentric type butterfly valve is a type of butterfly valve commonly used in various industries, including marine applications. Here’s a brief overview of its features, selection considerations, and usage:

Features:

Concentric Design: The wafer concentric butterfly valve features a concentric design where the stem passes through the center of the disc, ensuring a uniform seal around the circumference. This design minimizes turbulence and pressure drop while providing efficient flow control.
Wafer Style: These valves have a wafer-style body, which means they fit between two flanges without the need for additional bolts or nuts. This compact design saves space and facilitates easy installation and removal.
Resilient Seating: Most wafer concentric butterfly valves come with resilient seat materials such as EPDM or NBR, which provide excellent sealing properties and resistance to wear, corrosion, and chemicals.
Bidirectional Sealing: The concentric design allows for bidirectional sealing, meaning the valve can be installed in either direction without affecting its performance.
Manual or Actuated Operation: Wafer concentric butterfly valves are available in manual or actuated configurations. Manual valves are operated by hand, while actuated valves can be controlled remotely using pneumatic, electric, or hydraulic actuators for automated flow control.

Selection Considerations:

Size and Pressure Rating: Choose a valve size and pressure rating suitable for the intended application and operating conditions. Consider factors such as flow rate, system pressure, and compatibility with existing piping.
Material Construction: Select valve materials compatible with the fluid being handled and the environmental conditions. Common materials include stainless steel, carbon steel, ductile iron, and various alloys.
Seat Material: Consider the type of seat material (e.g., EPDM, NBR, PTFE) based on the fluid properties (e.g., temperature, viscosity, chemical compatibility) and sealing requirements.
Operation Type: Decide whether manual or actuated operation is preferred based on the level of automation required, accessibility, and control system integration.
Standards Compliance: Ensure the selected valve complies with relevant industry standards and certifications for quality, performance, and safety, such as ANSI, API, ISO, and marine classification societies’ requirements.

Usage:

Installation: Properly install the wafer concentric butterfly valve between flanges using appropriate gaskets and fasteners according to manufacturer specifications and industry standards.
Operation: Operate the valve manually or remotely using the designated controls, following established procedures for opening, closing, and adjusting the flow as needed.
Maintenance: Implement a regular maintenance schedule to inspect, clean, lubricate, and replace components as necessary to ensure optimal performance and longevity.
Monitoring: Periodically monitor the valve’s operation and condition for signs of leakage, wear, or malfunction, and take corrective action as required to prevent downtime or safety hazards.
Emergency Response: Establish protocols for responding to valve failures, leaks, or other emergencies, including shutdown procedures, isolation measures, and contingency plans to mitigate risks and minimize disruptions.

By considering these factors and following best practices for selection, installation, and maintenance, wafer concentric butterfly valves can effectively control flow and provide reliable performance in marine applications and other industrial settings.

Lug Concentric Type Butterfly Valve with Rubber Seated（tanghai valve)

March 27, 2024

A lug concentric type butterfly valve with rubber seated refers to a specific configuration of a butterfly valve commonly used in various industries, including marine applications. Let’s break down its features, considerations for selection, and how it’s typically used:

Features:

Concentric Design: Like other concentric butterfly valves, this type features a design where the stem passes through the center of the disc, ensuring a uniform seal around the circumference. This design minimizes turbulence and pressure drop while providing efficient flow control.
Lug Style: The valve body has lugs (also known as ears or tabs) on the valve’s periphery, allowing it to be bolted directly between flanges in the pipeline. This design provides easy installation and removal without needing to disconnect the entire pipeline.
Rubber Seating: The valve has rubber or elastomeric seating, typically made from materials like EPDM or NBR, which provide excellent sealing properties. Rubber seats offer resilience, chemical resistance, and longevity, making them suitable for various fluids and operating conditions.
Bidirectional Sealing: Similar to other concentric butterfly valves, this type can seal bidirectionally, allowing it to be installed in either direction without affecting its performance.
Manual or Actuated Operation: Lug concentric butterfly valves are available in both manual and actuated configurations. Manual valves are operated by hand, while actuated valves can be controlled remotely using pneumatic, electric, or hydraulic actuators for automated flow control.

Selection Considerations:

Size and Pressure Rating: Choose a valve size and pressure rating suitable for the intended application and operating conditions. Consider factors such as flow rate, system pressure, and compatibility with existing piping.
Material Construction: Select valve materials compatible with the fluid being handled and the environmental conditions. Common materials include stainless steel, carbon steel, ductile iron, and various alloys.
Seat Material: Consider the type of seat material (e.g., EPDM, NBR, PTFE) based on the fluid properties (e.g., temperature, viscosity, chemical compatibility) and sealing requirements.
Operation Type: Decide whether manual or actuated operation is preferred based on the level of automation required, accessibility, and control system integration.
Standards Compliance: Ensure the selected valve complies with relevant industry standards and certifications for quality, performance, and safety, such as ANSI, API, ISO, and marine classification societies’ requirements.

Usage:

Installation: Properly install the lug concentric butterfly valve between flanges using appropriate gaskets and fasteners according to manufacturer specifications and industry standards.
Operation: Operate the valve manually or remotely using the designated controls, following established procedures for opening, closing, and adjusting the flow as needed.
Maintenance: Implement a regular maintenance schedule to inspect, clean, lubricate, and replace components as necessary to ensure optimal performance and longevity.
Monitoring: Periodically monitor the valve’s operation and condition for signs of leakage, wear, or malfunction, and take corrective action as required to prevent downtime or safety hazards.
Emergency Response: Establish protocols for responding to valve failures, leaks, or other emergencies, including shutdown procedures, isolation measures, and contingency plans to mitigate risks and minimize disruptions.

By considering these factors and following best practices for selection, installation, and maintenance, lug concentric butterfly valves with rubber seating can effectively control flow and provide reliable performance in marine applications and other industrial settings.

Marine Butterfly Valve in the Application of Characteristics（Tanghai Valve）

October 23, 2023

The butterfly discs of the marine butterfly valve is installed in the diameter position of the ballistic path. Marine butterfly valve is easy to construct, small volume, light weight, only by the majority of more or less whole machine components. And as long as around 90 ° can quickly open and close, easy to operate, while the valve has excellent fluid mastery characteristics.

Marine butterfly valve in the closed position, the butterfly discs thickness is the only barrier when the medium flows through the valve body, so the pressure drop through the valve is very small, so there is a better flow control characteristic. Inertia sealing valve, the gasket can be set in the valve body or attached to the perimeter of the butterfly discs. Adoption of metal sealing valve is normally longer than inertia sealing valve life, but it is difficult to achieve complete sealing. Metal sealing can comply with the higher degree of task, inertia sealing is subject to the shortcomings of the degree of constraints.

If the marine butterfly valve as a flow control application, the main thing is to accurately choose the valve position and type. Marine butterfly valve construction principle is particularly suitable for the manufacture of large diameter valves. Butterfly valve is not only in alcohol, natural gas, chemical industry, ionization and other normal light industry to lose wide use, and also used in thermal power plant icing water fractions. For the clip type butterfly valve is to use the double head nut to butt the valve between the two ballistic flange, flange type butterfly valve is with flange on the valve, with the nut on the valve on the two ends of the flange is connected to the ballistic flange.

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.

Marine Valve for Mono Flange Butterfly Valve

May 31, 2023

Rubber Lined Butterfly Valve with Mono Flange(Single Flange)

Single Flange butterfly vlaves suitable for connecting standard and design standard is PN 10 normally.

Material of Mono flange butterfly valve

Marine Butterfly Valve,Ductile Iron Mono Flange;NBR/EPDM/Viton Lined,shaft stainless steel,Disc is alu-bronze or stainless steel.

Marine quality butterfly valve with a bonded NBR liner suitable for many duties including oils and hydrocarbons,Supplied bare shaft, please specify if lever, gearbox or actuator is required. The butterfly valve offers quick opening and closing with full flow in either direction and leak tight shut off. Flange gaskets not needed since the lining that extends onto the faces acts as a gasket.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. Wehave certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services.

Below is our wafer butterfly valve of marine valves, if you need to check more information, please click here: butterfly valve : https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/; https://www.tanghaivalve.com/double-flange-butterfly-valve-th-btv-df/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.

We are committed to “Build a top valve enterprise; Be a reliable partner!”

Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

How to install wafer butterfly valve and installation tips

March 11, 2022

Title: How to install wafer butterfly valve

In this article, let’s talk about the installation method of the wafer butterfly valve. Wafer type is a connection method of butterfly valve, that is, when installing on the pipeline, it is necessary to clamp the butterfly valve with two pieces of flanges, and then connect it with the flange on the pipeline. Corresponding to it is another connection method of butterfly valve, flange type. The installation of flanged butterfly valve will be shared with you in the future. Today we mainly talk about how to install the wafer butterfly valve in the form of pictures and texts.

JIS 10K-wafer butterfly valve-backup seat (4)

The structure of the wafer butterfly valve is relatively short and takes up little space. During installation, use the special flange for the wafer butterfly valve to fix it, and then put the fixed wafer flange into the middle of the flanges at both ends of the pipeline, and use bolts to fix it. The control of the fluid medium in the pipeline can be realized by fixing it through the special flange of the wafer butterfly valve and the pipeline flange (if there is no flange on the pipeline, the special flange for the butterfly valve needs to be welded on the pipeline). The wafer type butterfly valve occupies a small space, which makes it especially suitable for installation and use in situations where the space is narrow or the distance between pipes is relatively small.
The specific installation steps of the wafer butterfly valve are as follows:
1. Place the wafer butterfly valve between the two pre-installed special flanges for wafer butterfly valves, and pay attention to align the flange bolt holes with the round holes of the butterfly valve body.

2. Insert the bolts and nuts into the flange holes to connect the valve body and the flange, and correct the flatness in the method, but be careful not to overtighten the bolts and nuts.

3. Weld the flange on the pipe, this step should be done by spot welding.

4. Remove the wafer butterfly valve first.

5. Weld the two flanges on the pipe completely to complete the fixation.

6. After the weld between the flange and the pipe is cooled, install the wafer butterfly valve. At this time, pay attention to opening the butterfly plate a little.

7. Correct the installation position of the butterfly valve again, and tighten the bolts, but be careful not to over-tighten them.

8. Fully open the butterfly plate of the butterfly valve to ensure that the butterfly plate of the butterfly valve can be opened and closed freely.

9. Cross the bolts again and tighten them evenly;

10. After the above steps are completed, test the opening and closing of the butterfly valve again to ensure that the valve can open and close freely.

The above is the introduction of butterfly valve installation steps. Here, I would like to tell all friends who purchase butterfly valves. Before installing the wafer butterfly valve, pay attention to the handling and do not bump it at will. After installation, non-professionals should not disassemble it casually.

Double offset-wafer butterfly valve-D72F-150lbC (1)

Manual wafer butterfly valve installation skills

1. Storage work before installation: Store the manual wafer butterfly valve in a cool, dry and ventilated environment, and cover the valve to prevent the valve from being contaminated with dust and all debris.
2. Before the wafer butterfly valve is installed on the pipeline, the pipeline needs to be calibrated, and the positions of the pipes at both ends cannot be deviated. Body strain or rupture.
3. Before the valve is installed, the valve and all installed pipelines should be cleaned again to ensure that the inside of the valve and the pipeline is completely clean, and no dust is left.
4. Manual wafer butterfly valve belongs to manual butterfly valve, which requires frequent manual operation. Therefore, there are also requirements for the installation position of the manual butterfly valve. The installation position of the valve must be convenient for personnel to operate and maintain in the future. It has been demonstrated that the best position for manual valve installation is about 1.2 meters from the operating floor. For valves installed outdoors, cover the valve with some covering to prevent bad weather from affecting the valve.
5. When installing on the pipeline, make sure that the butterfly plate is in a closed state, so as to avoid collision and damage between the butterfly plate and the pipeline flange, which will affect the sealing performance.
6. After the manual wafer butterfly valve is installed, if there is an opening and closing failure during use, it is necessary to find out the cause and eliminate the failure. It cannot be forced to open and close by beating, prying or brute force.
The above is the whole content of the “manual wafer butterfly valve installation skills” introduced for you. Here, the editor also reminds everyone that after the valve is installed, it must be regularly maintained during the use of the valve. work, so as to ensure the normal and smooth operation of the valve. If you have purchase requirements for manual wafer butterfly valves, you are welcome to consult the official website of Tanghai 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

Video of center-lined butterfly valve:

Video of double 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

Working principle diagram of electric butterfly valve

August 2, 2021

Working principle diagram of electric butterfly valve
With the rapid development of my country’s industrial manufacturing industry, the demand for valves is also getting higher and higher, especially the use of electric butterfly valves and electric ball valves, which are the most prominent among many valves, and belong to the more common types of pipelines! The electric butterfly valve, as a component used to realize the on-off and flow control of the pipeline system, makes it more and more widely used in practical applications with its excellent quality and performance!

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

According to different connection methods, electric butterfly valves can generally be divided into the most common electric wafer butterfly valves and electric flange butterfly valves. The sealing materials include soft seal (normal temperature and pressure) and hard seal (high temperature and high pressure). The working power supply usually includes: AC220V, AC380V, DC24V, the input signal has 4~20mA 0~10v and other weak current signals. Finally, according to the control form, it is divided into switch type and regulation type. The switch type functions as a switch; the regulation type is used to adjust the flow rate, which can be accurate Adjusting the flow rate to thousand divisions is also a relatively expensive valve.
Working principle of electric butterfly valve:
The electric butterfly valve uses electric energy as the driving force, and the valve stem is driven by the electric device to make the butterfly plate produce a 90° rotation to achieve the opening and closing of the valve. It can also receive 4-20mA or other signals from the industrial automation control system to accurately control the valve opening. , So as to achieve the adjustment and control of different process parameters such as flow, temperature and pressure.
Related knowledge: dynamic diagram of butterfly valve working principle
Recommended products: Electric regulating butterfly valve Electric 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

electric fluorine-lined butterfly valve vs electric metal seated butterfly valve

August 2, 2021

The difference between electric fluorine-lined butterfly valve and electric hard seal butterfly valve
Electric butterfly valve is one of the most commonly used valves in industrial pipelines in recent years. In addition to ordinary opening and closing, it can also be used to adjust and control the pressure, flow, temperature and other parameters of various water, liquid, gas and other fluids. An important execution unit in the field of automation control, is widely used in chemical, electric power, petroleum, metallurgy, steam, environmental protection, fire-fighting systems and other occasions! In addition, there are many types of electric butterfly valves and various control modes, which can meet the requirements of various working conditions!

Fluorine lined butterfly valve-PTFE-WAFER (10)

Electric fluorine-lined butterfly valves and electric hard-sealed butterfly valves are the two most commonly used types of butterfly valves. The applicable medium and pressure temperature are completely different! But many people’s choice between the two often seems a bit uncertain! In the simplest terms, the two control modes are the same, the difference is the sealed structure. The electric fluorine-lined butterfly valve is suitable for corrosive media, but it can only be used at room temperature and pressure. The electric hard seal butterfly valve can be used for various pressures. temperature range! The detailed differences are as follows:
Electric fluorine-lined butterfly valve Electric hard-sealed butterfly valve
1. From the structure:
The hard sealing butterfly valve refers to that both sides of the sealing pair are made of metal materials or other harder materials. For soft sealing butterfly valves, the two contacting sealing surfaces can be separate or all of soft materials. For example, fluorine-lined butterfly valve means that the butterfly plate and valve seat are both wrapped in PTFE;

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

2. From the sealing performance:
The advantage of soft-sealed fluorine-lined butterfly valve is good sealing performance, but the disadvantage is that it is easy to age, wear, and has a short service life. The hard seal butterfly valve has a long service life, but the sealing performance is relatively worse than that of the soft seal.
3. From the conditions of use:
The soft-sealed fluorine-lined butterfly valve is used in normal temperature and pressure environment, and the hard-sealed butterfly valve can be used in low temperature, normal temperature, high temperature and other environments. Generally, it can be used for higher pressure, but the soft seal is not. However, the fluorine-lined butterfly valve has super corrosion resistance!
4. From the manufacturing point of view:
As for manufacturing, from a principle point of view, there is little difference between the two, mainly the difference in valve seats. The soft-seal fluorine-lined butterfly valve is a non-metallic structure, and the hard-seal butterfly valve is a metal structure. The hardness relationship between metals and the workmanship must be considered. Situation, what medium to go and so on.
Related knowledge: Working principle diagram of electric butterfly valve Selection of electric wafer butterfly valve and flange 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, API

Single eccentric|double eccentric|triple eccentric butterfly valve structure principle (diagram)

July 30, 2021

The evolution of butterfly valve sealing structure: single eccentric butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve

Butterfly valves have been widely used due to their low cost, small size, light weight and long life. With the development of my country’s industry, various industries have more and more stringent requirements for the performance of equipment, especially in some gas pipelines or other hazardous material pipelines, the butterfly valve must achieve zero leakage, so the sealing structure design of the butterfly valve has always been important Research topics.

With the rapid development of modern industrial technology, butterfly valves are widely used in pipeline control systems, especially large-diameter pipeline control systems where other control valves are difficult to apply. Generally, the valve seat of the butterfly valve is a fixed type, and its materials are polymer and metal. The polymer valve seat is mainly suitable for working conditions with lower temperature. Although the metal seat butterfly valve can meet the higher temperature and pressure However, the elasticity of the metal valve seat is lower than that of the polymer valve seat, and the sealing performance is poor. The improvement of various performances of butterfly valves is closely related to its continuous improvement. For example, the development of butterfly valve sealing structure technology has successively experienced the evolution process of ordinary butterfly valve, single eccentric butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve.

Since the rotation center of the butterfly plate (that is, the center of the valve shaft) and the sealing section of the butterfly plate are set eccentrically according to a, the butterfly plate sealing surface gradually separates from the valve seat sealing surface during the opening process of the butterfly valve, and 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. When the valve is fully opened, a gap x is formed between the two sealing surfaces, so that the relative mechanical wear and extrusion between the two sealing surfaces of the butterfly valve is greatly reduced during the opening and closing process. Ensure the sealing of the butterfly valve.

Since the rotation center of the butterfly plate (that is, the center of the valve shaft) and the center line of the valve body are offset by size b on the basis of the single eccentric butterfly valve, the sealing surface of the butterfly plate will be faster than the single eccentric sealing butterfly valve during the opening process of the butterfly valve. When the butterfly plate rotates to 8°～12°, the butterfly plate sealing surface is completely separated from the valve seat sealing. When it is fully opened, a larger gap y is formed between the two sealing surfaces. This type of butterfly valve is designed , Which greatly reduces the mechanical wear and extrusion deformation between the two sealing surfaces, and improves the sealing performance of the butterfly valve.

There are different types of eccentric sealing butterfly valves, and the fields of application and their respective characteristics are naturally different. But fundamentally speaking, the basic principles of eccentric sealing butterfly valves are similar.

Structural characteristics of single eccentric butterfly valve:

single eccentric butterfly valve structure diagram

1. The center of rotation of the disc plate (that is, the center of the valve shaft) is located on the center line of the valve body, and an A-size offset is formed on the sealing section of the valve plate. The single eccentric butterfly valve is that the rotation center of the disc plate is on the center line of the valve body, and the valve plate deviates a distance from the sealing surface, which is suitable for soft sealing.
2. When the valve is closed, the valve seat and the sealing surface of the valve plate are in a relatively interference contact state. To achieve the seal, it is mainly by pressing the sealing ring to expand in the peripheral direction to produce the sealing specific pressure and the pipeline pressure against the valve plate. It can only be sealed in one direction because of the strong force.
3. When the valve is opened, the contact side of the valve plate and the valve seat is separated from the valve seat, and the other side is always two-point contact along the axial direction of the half circumference. Repeated opening and closing of the sealing ring is easy to be damaged, which affects the sealing performance. It is impossible to achieve a metal seal.
4. From a geometric point of view, it is obvious that X does not exist in the above figure, and in turn there is a certain amount of interference.
Structural features of double eccentric butterfly valve:

double eccentric butterfly valve structure diagram

The center of rotation of the valve plate (that is, the center of the valve shaft) forms an offset of dimension A on the sealing section of the valve plate, and forms an offset of dimension B with the center of the valve body.
Since the center line of the valve seat and the center line of the valve body form a β angle offset on the basis of the double eccentric butterfly valve, the sealing surface of the butterfly plate immediately leaves the sealing surface of the valve seat at the moment of opening during the valve opening process of the butterfly valve. Only at the moment of closing does it contact and compress the seat sealing surface. When fully opened, a gap y is formed between the two sealing surfaces, which is the same as that of the double eccentric sealing butterfly valve. The design of this type of butterfly valve completely eliminates the mechanical wear and abrasion between the two sealing surfaces, making the butterfly valve more effective in its sealing performance and use. The life span has been greatly improved.

Structural features of triple eccentric butterfly valve:

triple eccentric butterfly valve structure diagram

The center of rotation of the valve plate (that is, the center of the valve shaft) forms an offset A on the sealing section of the valve plate, and an offset b from the center of the valve body; the centerline of the valve body sealing surface and the centerline of the valve seat (ie the centerline of the valve body) An angular offset of β is formed.
The uniqueness of the triple eccentric butterfly valve is that the stem shaft on which the butterfly plate is installed is a three-segment shaft structure. This three-segment shaft type valve stem has two shaft sections concentric, and the center line of the central shaft is deviated from the two ends of the axis by a center distance. , The butterfly plate is installed on the intermediate shaft section. Such an 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.
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

Types and classifications of butterfly valves

July 30, 2021

Types and classifications of butterfly valves
Butterfly valves can be divided into offset plate type, vertical plate type, inclined plate type and lever type according

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

to the structure. According to the sealing form, it is divided into two types: relatively sealed type and hard sealed type. Soft-sealed butterfly valves generally use rubber ring seals, and hard-sealed butterfly valves usually use metal ring seals. According to the connection type, they are divided into flange connection and wafer connection. According to the transmission mode, they are divided into manual, gear transmission, pneumatic, hydraulic and electric. .
Due to the wide variety of butterfly valves, and in special working conditions, the butterfly valve products used are also different. Therefore, for this type of valve, you should choose the type separately from the engineer! According to common types and classifications, butterfly valves can be divided into the following forms:
(1) Classification by structure
1. Center sealing butterfly valve

Types of wafer butterfly valves

2. Single eccentric sealing butterfly valve
3. Double eccentric sealing butterfly valve
4. Triple eccentric sealing butterfly valve
(2) Classified by link method
1. Wafer butterfly valve
2. Flanged butterfly valve
3. Lug butterfly valve
4. Welded butterfly valve
(3) Classified by working temperature
1. High temperature. t>450 °C butterfly valve.
2. Medium temperature butterfly valve. 120 C<t<450 ℃ butterfly valve.
3. Normal temperature butterfly valve. A butterfly valve of 40C<t<120 °C.
4. Low temperature butterfly valve. One 100<t<一40 °C butterfly valve.
(4) Classified by sealing surface material
1. Soft sealing butterfly valve.
(1) The sealing pair is composed of non-metallic soft material to non-metallic soft material.
(2) The sealing pair is composed of metallic hard materials and non-metallic soft materials.
2. Metal hard sealing butterfly valve. The sealing pair is composed of a metal hard material to a metal hard material.
(5) Classified by work pressure
1. Vacuum butterfly valve, a butterfly valve whose working pressure is lower than the atmospheric pressure of the standard stack.
2. Low pressure butterfly valve, butterfly valve with nominal pressure PN<1.6MPa.
3. Medium pressure butterfly valve, butterfly valve with nominal pressure PN of 2.5-6.4MPa.
4. High-pressure butterfly valve, a butterfly valve with a nominal pressure PN of 10.0-80.0MPa.
5. Ultra-high pressure butterfly valve, butterfly valve with nominal pressure PN>100MPa.
(6) Classified by sealing form

Double offset-lug butterfly valve-D372F-150lbC (1)

1. Forced sealing butterfly valve.
(1) Elastic sealing butterfly valve. The specific pressure of the seal is generated by the elasticity of the valve seat or the valve plate when the valve plate squeezes the valve seat when it is closed.
(2) External torque sealing butterfly valve. The seal specific pressure is generated by the torque applied to the valve shaft.
2. Pressure-filled and sealed butterfly valve. The specific sealing pressure is generated by the pressure of the elastic sealing element on the valve seat or valve plate.
3. Automatic sealing butterfly valve. The sealing specific pressure is automatically generated by the medium pressure.
Related knowledge: Types of valves Types of regulating valves Types of stop valves Types of ball valves Types of gate 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

Posts

Wafer Concentric Type Butterfly Valve (tanghai valve)

Lug Concentric Type Butterfly Valve with Rubber Seated（tanghai valve)

Marine Butterfly Valve in the Application of Characteristics（Tanghai Valve）

Marine Valve for Mono Flange Butterfly Valve

How to install wafer butterfly valve and installation tips

Application of double eccentric butterfly valve and triple eccentric butterfly valve

Working principle diagram of electric butterfly valve

electric fluorine-lined butterfly valve vs electric metal seated butterfly valve

Single eccentric|double eccentric|triple eccentric butterfly valve structure principle (diagram)

Types and classifications of butterfly valves

TH VALVE • PROFESSIONAL VALVE MANUFACTURER

GET IN TOUCH WITH US