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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.

Butterfly Valve of Marine Valves(tanghai valve)

March 27, 2024

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:

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.
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.
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.
Bidirectional Sealing: Butterfly valves are inherently bidirectional, meaning they can effectively seal flow in both directions, allowing flexibility in installation and operation.
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:

Size and Pressure Rating: Choose a valve size and pressure rating suitable for the intended application and system requirements aboard the ship.
Material Compatibility: Select materials compatible with the fluids being handled and resistant to corrosion in the marine environment.
Sealing Material: Consider the type of sealing material based on temperature, pressure, and fluid properties to ensure reliable performance and longevity.
Operation Type: Determine whether manual or actuated operation is preferable based on accessibility, control requirements, and automation needs.
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:

Installation: Install the marine butterfly valve correctly according to manufacturer specifications, ensuring proper alignment, bolt torquing, and gasket sealing between flanges.
Operation: Operate the valve using the designated controls, whether manual or actuated, following established procedures for opening, closing, and adjusting flow rates as needed.
Maintenance: Implement a regular maintenance schedule to inspect, clean, lubricate, and replace components as necessary to ensure optimal performance and reliability.
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 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)

October 23, 2023

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）

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 butterfly valve–Application of Marine Butterfly Valves

June 29, 2023

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.
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

July 25, 2022

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)

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

What are the commonly used valves

August 27, 2021

The valve is a pipeline accessory, used to open and close the pipeline and control the flow of fluid medium in the pipeline. The functions of the valve in the pipeline include cut-off, regulation, diversion, prevention of reverse flow, stabilization, diversion or overflow and pressure relief. There are many types of valves. As the control components of fluid control systems, from the simplest butterfly valves and gate valves to the various valves used in extremely complex automatic control systems, there are many varieties and specifications.

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

Valves can be used to control the flow of various types of fluids, such as air, water, steam, various corrosive media, mud, oil, liquid metal, and radioactive media. The application range covers various industries. Although there are many types of valves, what are the commonly used valves? This article introduces you one by one:

There are five types of commonly used valves: butterfly valves, gate valves, check valves, ball valves, and stop valves.

Butterfly valve:
The butterfly valve, also known as the flap valve, is a simple and easy-to-use regulating valve. The butterfly plate in the body of the butterfly valve is the closing part of the valve, which is in the shape of a disc. The working principle is that the butterfly plate rotates around the valve shaft to realize the valve. Open and close, usually, the butterfly plate is driven by the valve stem and rotates 90° to complete one opening and closing, and achieve the purpose of interception. If you change the deflection angle of the butterfly plate, it can also be used as a flow control. Under normal circumstances, butterfly valves are often used for on-off control of low-pressure pipeline media.
Wafer butterfly valve and flange butterfly valve are the two connection forms of butterfly valve. The butterfly valve is suitable for making large-diameter valves, suitable for natural gas, liquefied petroleum gas, city gas, cold and hot air, chemical smelting and power generation, environmental protection, building water supply and drainage, etc. It is used to regulate and cut off the flow of media on the pipelines that transport various corrosive and non-corrosive fluid media in the system.

gate valve:

non-rising-stem-gate-valve-IS&Y

Gate valves are usually used for interception in pipeline systems. Its opening and closing parts are gates. The movement direction of the gate is perpendicular to the direction of the medium flow in the pipeline. The gate rises and the valve opens to realize the flow of the pipeline medium; the gate falls, The valve is closed, and the flow of the pipeline medium is cut off. The gate valve can only be fully opened or fully closed to cut off the flow of the medium, and cannot be used for adjustment and throttling. Therefore, the gate valve is generally used to keep the gate valve gate plate fully open and fully closed, and is used in a pipeline environment that does not need to be opened and closed frequently.
According to the structure of the gate, the gate valve can be divided into two types: wedge gate valve and parallel gate valve. Wedge gate valves can be divided into three types: single gate valve, double gate valve and elastic gate valve.

Check valve:
The check valve is also a list valve or check valve, which is an automatic valve, which

double-wing-check-valve-3

means that the check valve works automatically and does not require manual operation. When the medium flows through the check valve, under the pressure impact of the fluid medium, the check valve The valve flap of the return valve opens automatically and the medium passes through; after the medium flow is cut off, the valve flap automatically closes under the force of its own spring device to prevent the medium from flowing back and backflow.
Check valves are only suitable for installation in pipelines where the medium flows in one direction. The main function is to prevent the medium from flowing backwards, to prevent the pump and drive motor from reversing, and to discharge the container medium.

Globe valve:
The globe valve, also known as the shut-off valve, is a forced-sealing valve. That is to say, unlike the automatic operation of a check valve, the shut-off valve must apply pressure to the disc when it is closed to force the sealing

globe valve body

surface to not leak. When the medium enters the valve from below the disc, the flow direction changes, so the resistance that needs to be overcome to close the shut-off valve is the friction between the valve stem and the packing, as well as the thrust generated by the pressure of the medium, and the force to close the valve. The force is larger than that of opening the valve, so the diameter of the valve stem should be larger, otherwise the valve stem will bend failure. The flow resistance of the stop valve is higher than other valves.
The shut-off valve can be used to cut off the medium like a gate valve, but more often, people use the shut-off valve to adjust the flow.

Ball valve:
The ball valve evolved from the rotary valve. It is the same as the butterfly valve in that it also needs to be rotated 90 degrees to open and close. The difference is that the butterfly

ball valve (8)

valve is a butterfly plate, and the cock of the ball valve is a sphere, with a circular through hole or channel passing through its axis.
The ball valve can cut off, distribute and change the flow direction of the medium in the pipeline, and only need to rotate 90 degrees and a small torque can be closed tightly. Therefore, the ball valve is most suitable for use as a switch and shut-off valve. At present, it has been widely used in petroleum refining, long-distance pipeline, chemical industry, papermaking and other industries.

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

How to choose a valve in the chemical industry

August 5, 2021

The media transported in various pipelines in the chemical industry are usually corrosive, such as sulfuric acid, hydrochloric acid, nitric acid and other corrosive media. All corrosion protection is the most basic requirement of chemical equipment. Chemical valves are of course no exception, and the selection of valve materials must be corrosion-resistant. If the chemical valve is wrongly selected, it will damage the equipment at the slightest level, or cause serious accidents, causing injury to machinery, equipment and even people. However, for different corrosive media, the selection of valves is also different. This article will talk about the key points of valve material selection for some common chemical media:

lug type butterfly valve, ductile iron, center lined,

Hydrochloric acid: Most metal materials, including various stainless steel materials, are not resistant to hydrochloric acid corrosion, and high-silicon ferro-molybdenum can only be used in hydrochloric acid below 50°C and 30%. Contrary to metal materials, most non-metal materials have good corrosion resistance to hydrochloric acid, so rubber-lined valves (such as fluoroplastics, etc.) are the best choice for transporting hydrochloric acid. But if the temperature of the medium exceeds 150°C, or the pressure is greater than 16 kg, any plastics (including fluoroplastics and even polytetrafluoroethylene) will be difficult to handle. For hydrochloric acid exceeding this condition, there is no ideal valve currently on the market.

Sulfuric acid: As one of the strong corrosive media, sulfuric acid is an important industrial raw material with a wide range of uses. Different concentrations and temperatures of sulfuric acid have great differences in the corrosion of materials. For concentrated sulfuric acid with a concentration of more than 80% and a temperature of less than 80°C, carbon steel and cast iron have good corrosion resistance, but it is not suitable for high-speed flowing sulfuric acid. Not suitable for use as a valve material; ordinary stainless steels such as 304 and 316 have limited use for sulfuric acid media. Therefore, pump valves for transporting sulfuric acid are usually made of high-silicon cast iron (difficult to cast and process) and high-alloy stainless steel (20 alloy valve). Fluoroplastics have better resistance to sulfuric acid, and fluorine-lined valves (recommended by Tanghai Valves) are a more economical choice. If the pressure is too high and the temperature rises, the point of use of the plastic valve will be impacted, and you can only choose the more expensive ceramic ball valve.

Nitric acid: Most metals are rapidly corroded and destroyed in nitric acid. Stainless steel is the most widely used nitric acid resistant material. It has good corrosion resistance to all concentrations of nitric acid at room temperature. Note that stainless steel containing molybdenum (such as 316, The corrosion resistance of 316L) to nitric acid is not better than that of ordinary stainless steel (such as 304, 321), and sometimes even worse.

Acetic acid: Acetic acid is one of the most corrosive substances in organic acids. Ordinary steel will be severely corroded in acetic acid at all concentrations and temperatures. Stainless steel is an excellent acetic acid resistant material. 316 stainless steel containing molybdenum is also suitable for high temperature and rarefied materials. Acetic acid vapor. For demanding requirements such as high temperature and high concentration of acetic acid or other corrosive media, high alloy stainless steel or fluoroplastic pumps can be used.

Salt water/sea water: The corrosion rate of ordinary steel in sodium chloride solution, sea water and salt water is not very high, and generally must be protected by paint; all kinds of stainless steel also have a very low uniform corrosion rate, but may cause local corrosion due to chloride ions. It is usually better to use 316 stainless steel.

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

Pneumatic butterfly valve working principle diagram

July 28, 2021

Pneumatic butterfly valve working principle diagram
Pneumatic butterfly valve is a kind of general-purpose valve that is particularly widely used. Nowadays, many chemical industry, paper industry, coal industry, petroleum, medical, etc. will use valves, especially pneumatic valves, and if the use is relatively large, it must be Pneumatic butterfly valves are extremely common on many pneumatic pipelines! Especially in low-pressure large and medium-caliber pipelines, it is used more and more. The larger the diameter, the more economical and economical than other valves.

Double offset-butterfly valve-D972F-150lbC (1)

Pneumatic butterfly valves are so widely used because of their simple structure, easy maintenance, and rapid switching, which can not only improve work efficiency, but also reduce maintenance time. According to customer requirements, seal rings of different materials and parts of different materials can be selected to be suitable for different media and working conditions, so that the pneumatic butterfly valve can achieve great results.
Working principle of pneumatic butterfly valve:
The pneumatic butterfly valve uses compressed air as the power source, and drives the valve stem to control the disc-shaped butterfly plate to rotate around the axis. The initial position of the valve is determined according to actual needs. When the valve rotates 90° from the initial position, an action ends (by opening To off, or from off to on), otherwise, another action (from off to on, or from on to off) ends.
The execution speed of the pneumatic butterfly valve is relatively fast, it is not easy to be damaged due to jamming during the movement process, and does not require the hands of workers. It can not only be used as a cut-off valve, but also can be equipped with a valve positioner to achieve the function of regulating and controlling the pipeline medium. Pneumatic butterfly valve actuators are divided into single-acting and double-acting forms. The double-acting is vent opening and vent closing! Among them, the single-acting actuator has a spring return function, which can be

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

automatically closed or opened in the case of gas or power failure, with a high safety factor!
Related knowledge: dynamic diagram of butterfly valve working principle
Recommended products: Pneumatic regulating 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

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