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Dual plate check valve in marine valve

A double plate check valve, also known as a dual plate check valve or wafer check valve, is a type of non-return valve commonly used in various fluid systems on ships. It is designed to allow fluid to flow in one direction while preventing backflow, ensuring that the fluid flow is unidirectional. Here are some key features and details about double plate check valves used in ship valves:

Key Features of Double Plate Check Valves

1,Dual Plates: The valve has two spring-loaded plates or discs that open when fluid flows in the desired direction and close when there is a reversal of flow. This design ensures a quick response to changes in flow direction.

2,Wafer Type Design: These valves have a compact and lightweight wafer design, making them easy to install between flanges in a pipeline. They occupy less space compared to other types of check valves.

3,Non-Slam Closure: The spring-loaded mechanism ensures a non-slam closure, reducing the risk of water hammer, which can cause damage to the piping system.

4,Low Pressure Drop: The dual plate design offers minimal resistance to flow, resulting in a low-pressure drop across the valve.

5,Material Options: These valves are available in various materials such as stainless steel, cast iron, and other alloys to suit different types of fluids and environmental conditions, including seawater applications.

6,Versatility: Suitable for a wide range of applications including ballast systems, cooling systems, fuel systems, and bilge systems on ships.

Advantages in Marine Applications

1,Space-Saving: The compact design is particularly advantageous in the confined spaces typically found in marine engine rooms and other shipboard locations.

2,Durability: Marine environments are harsh, and the materials used in these valves are selected for their corrosion resistance and durability.

3,Maintenance: Double plate check valves are designed for easy maintenance, which is critical in marine operations where downtime needs to be minimized.

4,Efficiency: By preventing backflow and ensuring a unidirectional flow, these valves contribute to the efficiency and reliability of the ship’s fluid systems.

Common Uses on Ships

Ballast Water Systems: Ensuring the correct flow direction in ballast water management, crucial for the stability and balance of the ship.

Cooling Water Systems: Used in engine cooling systems to ensure the proper flow of seawater or freshwater for cooling purposes.

Fuel Systems: Preventing backflow in fuel lines, which is critical for the safe and efficient operation of ship engines.

Bilge Systems: Ensuring the proper discharge of bilge water and preventing backflow into the bilge.

Installation and Maintenance Tips

Proper Alignment: Ensure the valve is correctly aligned with the flow direction indicated on the valve body during installation.

Regular Inspection: Periodic inspection and maintenance are essential to ensure the valve operates correctly and to prevent potential failures.

Material Compatibility: Select the appropriate material for the valve based on the specific application and the type of fluid being handled to avoid corrosion and other issues.

In summary, double plate check valves are a critical component in shipboard fluid systems, providing reliable performance, efficiency, and ease of maintenance, which are essential for the safe and effective operation of maritime vessels.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have 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:https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/.

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!

Understanding the Role and Design of Marine Butterfly Valves

Introduction: Marine butterfly valves are crucial components in the maritime industry, playing a vital role in controlling the flow of fluids onboard ships and offshore platforms. Understanding their design, functionality, and applications is essential for ensuring efficient and reliable operation in marine environments.

Design and Construction: Marine butterfly valves are typically designed with a disc or plate that pivots on a central axis within the pipe. This disc, resembling the wings of a butterfly, can be rotated to either permit or restrict the flow of fluids. The valve operates by turning the disc parallel to the flow direction to allow fluid passage or perpendicular to block the flow.

These valves are constructed using materials that can withstand the corrosive effects of seawater and harsh marine conditions. Common materials include stainless steel, bronze, and other corrosion-resistant alloys. Additionally, marine butterfly valves are often equipped with sealing materials such as EPDM or Viton to ensure tight shut-off and prevent leakage.

Applications: Marine butterfly valves find applications in various onboard systems, including:

Ballast Systems: Controlling the flow of water for stability and trim adjustments.

Cooling Water Systems: Regulating the flow of seawater for engine cooling and heat exchange.

Bilge Systems: Managing the discharge of wastewater and bilge water.

Fuel Oil Transfer Systems: Controlling the flow of fuel oil for propulsion and power generation.

These valves are preferred for their compact design, lightweight construction, and ease of operation, making them suitable for use in confined spaces aboard vessels.

 

Maintenance and Inspection: Regular maintenance and inspection of marine butterfly valves are essential to ensure optimal performance and prevent failures. This includes lubrication of moving parts, checking for signs of corrosion or wear, and testing valve operation to verify functionality.

Conclusion: Marine butterfly valves play a critical role in the safe and efficient operation of marine systems. Understanding their design, applications, and maintenance requirements is essential for ensuring reliable performance and safety at sea.

 

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly

valve, check valve, gate /Knife gate valve. We have 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:https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/.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!

Concentric Type Butterfly valve with resilient seated

A concentric type butterfly valve with a resilient seat is a type of valve commonly used in various industries for flow control. Let’s break down its components:

Concentric Design: In this design, the centerline of the stem (the shaft that controls the opening and closing of the valve) is also the centerline of the disc (the “butterfly” part of the valve). This design allows for smooth flow regulation and minimal turbulence.

Butterfly Valve: This valve uses a disc as the flow control element. The disc is mounted on a shaft in the center of the valve’s body. When the valve is open, the disc is parallel to the flow, allowing fluid to pass through. When the valve is closed, the disc is perpendicular to the flow, blocking it.

Resilient Seat: The seat of the valve is the part where the disc makes contact when the valve is closed. Resilient seats are made from materials like EPDM (ethylene propylene diene monomer) or NBR (nitrile butadiene rubber). These materials are resilient, meaning they can deform slightly to ensure a tight seal when the valve is closed. Resilient seats also provide good resistance to wear and tear and are suitable for a wide range of operating temperatures.

wafer type double stems butterfly valve (2)

In practical terms, a concentric type butterfly valve with a resilient seat is often used in applications where a tight shut-off is required, such as in water treatment plants, HVAC systems, and various industrial processes. The resilient seat ensures a reliable seal, and the concentric design allows for smooth operation and minimal pressure drop across the valve.

wafer type butterfly valve (7)

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have 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.

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!

Wafer Concentric Type Butterfly Valve (tanghai valve)

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:

  1. 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.
  2. 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.
  3. 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.
  4. Bidirectional Sealing: The concentric design allows for bidirectional sealing, meaning the valve can be installed in either direction without affecting its performance.
  5. 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:

  1. 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.
  2. 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.
  3. 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.
  4. Operation Type: Decide whether manual or actuated operation is preferred based on the level of automation required, accessibility, and control system integration.
  5. 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:

  1. Installation: Properly install the wafer concentric butterfly valve between flanges using appropriate gaskets and fasteners according to manufacturer specifications and industry standards.
  2. Operation: Operate the valve manually or remotely using the designated controls, following established procedures for opening, closing, and adjusting the flow as needed.
  3. Maintenance: Implement a regular maintenance schedule to inspect, clean, lubricate, and replace components as necessary to ensure optimal performance and longevity.
  4. 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.
  5. 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)

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:

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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:

  1. 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.
  2. 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.
  3. 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.
  4. Operation Type: Decide whether manual or actuated operation is preferred based on the level of automation required, accessibility, and control system integration.
  5. 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:

  1. Installation: Properly install the lug concentric butterfly valve between flanges using appropriate gaskets and fasteners according to manufacturer specifications and industry standards.
  2. Operation: Operate the valve manually or remotely using the designated controls, following established procedures for opening, closing, and adjusting the flow as needed.
  3. Maintenance: Implement a regular maintenance schedule to inspect, clean, lubricate, and replace components as necessary to ensure optimal performance and longevity.
  4. 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.
  5. 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.

Butterfly Valve of Marine Valves(tanghai valve)

A butterfly valve used in marine applications, often referred to simply as a marine butterfly valve, is a critical component in ship systems for controlling the flow of fluids such as water, fuel, and various other liquids.

Here’s an overview Features: 

  1. corrosion Resistance: Marine environments expose valves to corrosive elements like saltwater. Hence, marine butterfly valves are typically made from materials such as bronze, stainless steel, or other corrosion-resistant alloys.
  2. Compact Design: Space is often limited aboard ships, so marine butterfly valves are designed to be compact and lightweight while still providing efficient flow control.
  3. Resilient Seating: Many marine butterfly valves feature resilient seating made of materials like EPDM or NBR, which offer excellent sealing properties and resistance to wear, corrosion, and chemicals.
  4. Bidirectional Sealing: Butterfly valves are inherently bidirectional, meaning they can effectively seal flow in both directions, allowing flexibility in installation and operation.
  5. Manual or Actuated Operation: Marine butterfly valves can be operated manually using a hand lever or wheel, or they can be equipped with pneumatic, electric, or hydraulic actuators for remote operation and automation.

Selection Considerations:

  1. Size and Pressure Rating: Choose a valve size and pressure rating suitable for the intended application and system requirements aboard the ship.
  2. Material Compatibility: Select materials compatible with the fluids being handled and resistant to corrosion in the marine environment.
  3. Sealing Material: Consider the type of sealing material based on temperature, pressure, and fluid properties to ensure reliable performance and longevity.
  4. Operation Type: Determine whether manual or actuated operation is preferable based on accessibility, control requirements, and automation needs.
  5. Compliance and Certification**: Ensure the selected valve meets relevant industry standards and certifications for marine applications, such as those from classification societies like DNV, ABS, or Lloyd’s Register.

Usage:

  1. Installation: Install the marine butterfly valve correctly according to manufacturer specifications, ensuring proper alignment, bolt torquing, and gasket sealing between flanges.
  2. Operation: Operate the valve using the designated controls, whether manual or actuated, following established procedures for opening, closing, and adjusting flow rates as needed.
  3. Maintenance: Implement a regular maintenance schedule to inspect, clean, lubricate, and replace components as necessary to ensure optimal performance and reliability.
  4. 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.
  5. 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 adhering to best practices for selection, installation, operation, and maintenance, marine butterfly valves can effectively control flow and contribute to the safe and efficient operation of ship systems.

Marine Butterfly Valves are Used to Close or Open the Medium in the Ballistic Channel (Tanghai Valve)

Valve selection of a single variety of valve goods, marine valve speech is inconsistent, partly by use (such as chemical, alcohol, power station, etc.), partly by medium (such as water vapor, atmosphere valve, etc.), partly by material (such as pig iron valve, cast steel valves, forged steel valves, etc.), partly by the way of connection (such as fingerprints, flange valves, etc.), and partly by the measurement (such as high-temperature valves, low-temperature valves, etc.). The following is a list of the most common types of pressure reducing valves for marine use.

Marine pressure reducing valve – used to actively elevate the ballistic and facilities within the medium pressure. Marine pressure-reducing valve medium through the valve flap gap, marine pressure-reducing valve occurs barrier formation pressure loss, to reach the means of pressure reduction. Trap – used to steam ballistic actively remove condensate, to prevent the loss of steam or leakage. Marine butterfly valve is used to close or open the ballistic medium. Can also be used for conditioning. Insurance valve – used in boilers, ware facilities and ballistic, when the media pressure stumbles over the rule value, can actively remove the excess media pressure, to protect the consumption of operational insurance.

In the power station valves can master the boiler and steam engine operation; in alcohol, chemical consumption, the valve also plays a role in mastering the whole consumer facilities and process line of the abnormal operation. In other units are also like that. In spite of this, valves are often ignored by the crowd compared with other goods. Similarly: when installing tools and facilities, people often focus on the main tools and facilities range. Therefore, for the valve selection, installation, use and so on need to be careful.

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 Butterfly Valve in the Application of Characteristics（Tanghai Valve）

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 butterfly valve–Application of Marine Butterfly Valves

Marine butterfly valve is a kind of valve used to control or cut off fluid in liquid or gas flow pipeline on board. The characteristics of marine butterfly valves are simple structure, light weight, convenient operation, and good safety in use. Below, we will introduce marine butterfly valves in several aspects.

 1、 Application of Marine Butterfly Valves

Marine butterfly valves are widely used for regulating and cutting off liquid flow and gas in various oil tankers, Chemical tanker, natural gas tankers, liquefied gas tankers and rescue ships. And it can also be applied in other equipment and pipelines, such as petrochemical, energy, metallurgy, power, water treatment and other fields.

 2、 Structure of butterfly valve

Marine butterfly valves generally adopt a circular flat surface on the outside, and are composed of bent plates and closed gaskets on the inside. The valve stem and valve disc are rigidly connected through suitable mechanical connections, and the valve disc is configured into the pipeline to control the flow rate by relying on the flow force itself.

 3、 Characteristics of Marine Butterfly Valves

 （1）Simple structure, small size, light weight, and low flow resistance.

（2）Quick opening and closing, easy to operate, and reduces fluid switching time.

 （3） Corrosion resistance, reliable sealing, and good leak prevention effect.

 （4）Long service life and simple maintenance.

 （5） Its special structural design ensures that it still retains the advantages of no combustion, leak prevention, and fire resistance under low pressure, small diameter, and critical conditions.

4、 Selection Method of Marine Butterfly Valves

When selecting a marine butterfly valve, it is necessary to consider parameters such as the nominal diameter, pressure rating, mode of action, and medium temperature of the butterfly valve. It is best to make a choice based on specific conditions.

It is necessary to consider the operating temperature and medium characteristics, and appropriate valve diameters and shear forces should be designed based on the flow speed of the medium, and appropriate materials or sealing forms should be selected.

5、 How to Use and Maintain Marine Butterfly Valves

When using marine butterfly valves, attention should be paid to the installation direction and the position of the blocking plate to ensure that the valve is straight and to avoid tilting damage and leakage during operation.

For the maintenance and upkeep of marine butterfly valves, it is necessary to conduct timely inspections, regularly lubricate the valve and its surrounding components, and clean the operating bearings, gaskets, sealing surfaces, and bearings. Special attention should be paid to key areas.

Finally, we need to regularly conduct statistics and analysis on the usage of marine butterfly valves, compare them with other similar equipment, identify problems in the operation of butterfly valves, and promptly handle them. Only by doing well in daily maintenance and paying sufficient attention can the normal operation of butterfly valves be guaranteed and their service life be extended.

Finally, we need to regularly conduct statistics and analysis on the usage of marine butterfly valves, compare them with other similar equipment, identify problems in the operation of butterfly valves, and promptly handle them. Only by doing well in daily maintenance and paying sufficient attention can the normal operation of butterfly valves be guaranteed and their service life be extended.
Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry andproducts 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:https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/.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!

Stem structure and Integral Seat of centerline wafer butterfly valve

The centerline wafer butterfly valve can be divided into two types: pinless butterfly valve and pinned butterfly valve. The main difference between them is whether the valve plate and valve stem are fixed with pins. The pinned butterfly valve and the pinless butterfly valve

JIS 10K-wafer butterfly valve-backup seat (1)

JIS 10K-wafer butterfly valve-backup seat (1)

correspond to the needs of different working conditions, and more depends on the needs of users. Because the process of the pinless butterfly valve is more effective and more complicated, and there is no pin hole on the surface of the butterfly plate, its price will also be a little more expensive than that of the butterfly valve with a pin. And relatively speaking, it does not appear pitting corrosion and point leakage. Now let’s take a look at the pinless structure of the centerline wafer butterfly valve:

Centerline Wafer Type Butterfly Valve Double Half Shaft Structure
The double half shaft is a kind of structural performance of the midline wafer butterfly valve, also called the square shaft. Corresponding to it is the through shaft. Double semi-shaft means that there is a shaft on the upper and lower sides of the valve plate of the butterfly valve. The upper shaft and the valve stem are integrally formed to act as a transmission, and the lower shaft is a circular shaft, which plays the role of positioning the valve plate. Since the connection between the upper shaft, the valve stem and the valve plate is usually through a square shaft – a square hole, there are also hexagonal connections. Therefore, the processing of the valve plate is usually processed by punching, slotting or EDM, and the processing efficiency is low. In addition, the lower shaft also needs to pass through the through hole at the bottom of the valve body to be installed. After that, a gasket and a retaining ring need to be added to the bottom to fix the lower shaft. The processing and assembly of the valve body also increases the difficulty. Therefore, this structure is only used in large sizes now.

Large and small head shaft structure of centerline wafer butterfly valve
The stem of this midline wafer type butterfly valve is a flat shaft that passes through the valve plate. At the lower end, the diameter is reduced to a size smaller than the flat hole of the valve plate to pass through the valve plate, and the bottom of the valve body is positioned to ensure the valve Concentricity and symmetry of the plate. The processing of the through hole of the valve plate only requires a high degree of coaxiality of the single-side feed. In addition, there is no through hole at the bottom of the valve body, which also avoids external pollution caused by the leakage of the valve body. However, due to the variable diameter of the valve stem and the valve body, the processing cost is appropriately increased, and the upper and lower holes of the valve seat are not of equal diameter, which is easy to cause errors in the assembly process.

Equal Diameter Flat Shaft for Centerline Wafer Type Butterfly Valve
The structure of this midline wafer butterfly valve is evolved from the structure of the large and small head shafts. The valve stem is an equal-diameter shaft. The bottom is processed into double D type and the valve plate forms a close fit to ensure the transmission of the valve plate. It is also a flat hole, but the direction of the flat hole is rotated by a 90°, so as to ensure that when the valve is at the closing point or close to the closing point, the valve stem is in contact with the valve body bushing with a circular surface to ensure the symmetry of the valve plate and the same The axial degree can not only avoid the bending deformation of the valve stem but also make the valve close tightly. Since the valve body and seat are the same size in both directions, the efficiency can be greatly improved during processing and assembly. This kind of structure is simple and practical, and has the characteristics of high processing efficiency, quick assembly, tight coordination, economical saving and so on.

We all know that the seal of the centerline wafer butterfly valve is inseparable from the sealant sleeve, and the integral sealant sleeve is actually a wafer-type butterfly valve with a reliable sealing and leak-proof valve seat. It includes the annular valve body of the upper and lower valve necks, the annular valve seat embedded on the inner wall of the valve body, the butterfly plate, and the valve body which is rotatably installed on the valve body through the valve seat and the butterfly plate through the upper and lower valve necks. The valve stem and the transmission device, the valve seat is composed of an annular skeleton and an integral sealant sleeve formed integrally with it.

The integral sealant sleeve of the midline wafer butterfly valve consists of an inner wall sealant layer covering the inner wall of the skeleton and an end face sealant layer covering the two ends of the skeleton respectively. It is characterized in that the two end-face sealant layers are divided into a circumferential extension edge covering the end face of the annular valve body, and the extension edge of one end-face sealant layer is integrally and fixedly connected with the end-face sealant layer. The fixed epitaxial edge of the end face sealant layer on the other side and the end face sealant layer are detachably connected movable epitaxial edges.

The birth of this midline wafer butterfly valve seat is that the butterfly valve, as a fluid pipeline valve, has very strict requirements on its tightness. However, the current wafer butterfly valve still has the problem of running and dripping, which affects the normal use. Therefore, how to improve the structure of the valve seat has become a concern. However, the integral sealing valve seat, which is reliably sealed against leakage, can completely cover and seal the joint between the valve seat and the annular inner wall of the valve body. Therefore, it can effectively prevent the fluid in the pipeline from entering the valve body, effectively avoid the leakage of the valve caused by engineering construction and other reasons, and ensure the normal operation of the valve. In addition, the structure of the fixed epitaxial edge and the movable epitaxial edge is also convenient to assemble and use. While ensuring the quality of the project, it saves costs and is suitable for market promotion.

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

Related news/knowledge:

Stem structure of centerline wafer butterfly valve
Reasons and solutions for leakage of valve sealing surface
Characteristics of the centerline wafer butterfly valve
Centerline flange butterfly valve

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