Knowledge Archives

Introduction of U-shaped flange butterfly valve

July 27, 2020

What is U-shaped flange connection butterfly valve?
The U shaped butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. Moreover, it can be opened and closed quickly

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

by rotating 90°, and the operation is simple. At the same time, the valve has good fluid control characteristics.
The butterfly plate of the U type butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully opened.
The butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. Moreover, it can be opened and closed quickly by rotating 90°, and the operation is simple. At the same time, the valve has good fluid control characteristics. When the flange butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has better flow control characteristics. The butterfly valve has two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate.
Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the defect of being limited by temperature.
If the butterfly valve is required to be used as a flow control, the main thing is to correctly choose the size and type of the valve. The structure principle of the butterfly valve is especially suitable for making large diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, water treatment, etc., but also used in cooling water systems of thermal power stations.
Commonly used butterfly valves include wafer butterfly valves and flange butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipe flanges. Flange type butterfly valve has flanges on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flanges.
When in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has better flow control characteristics. The butterfly valve has two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate. Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the defect of being limited by temperature.
If the butterfly valve is required to be used as a flow control, the main thing is to correctly select the size and type of the valve. The structure principle of the butterfly valve is especially suitable for making large diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, water treatment, etc., but also used in cooling water systems of thermal power stations.
Commonly used butterfly valves include wafer butterfly valves and flange butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipe flanges. Flange type butterfly valve has flanges on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flanges.

Uses and characteristics of manual butterfly valve (4)

July 21, 2020

Installation and maintenance of manual butterfly valve:
During installation, the disc should stop in the closed position. The opening position should be determined according to the rotation angle of the butterfly plate. For

wafer type butterfly valve, with handle (13)

the butterfly valve with bypass valve, the bypass valve should be opened before opening, and the installation should be carried out according to the manufacturer’s installation instructions. The heavy butterfly valve should be set with a firm foundation.

Comparison of ordinary butterfly valve and gate valve:

Which of the ordinary butterfly valve or gate valve with the same nominal pressure and nominal diameter has better tightness and is not easy to leak?

The airtightness of the gate valve is better than that of the butterfly valve, but there are also manufacturers’ butterfly valves that have better airtightness. This type of valve should generally be installed horizontally in the pipeline.

The gate valve is large in size and takes up a lot of space.

The butterfly valve is small in size and takes up little space.

When selecting, the temperature of the medium, the sealing of the valve and the packing must also be considered.

The specification stipulates that butterfly valves with a nominal diameter greater than 50 are used.

The elastic metal sealing butterfly valve is a national key new product. The high-performance manual butterfly valve adopts a double eccentric and a special oblique cone oval sealing structure. It solves the shortcoming of the traditional eccentric butterfly valve that the sealing surface is still in sliding contact friction at the moment of opening and closing 0°～10°, and the sealing surface of the butterfly plate is separated at the moment of opening, and the effect of sealing when the contact is closed is achieved. Good purpose.

Material of manual butterfly valve:
1. Valve body material: gray cast iron, ductile iron, cast steel, aluminum alloy, stainless steel, etc.;

2. Valve plate material: duplex stainless steel, nylon 11 plate, galvanized plate, aluminum bronze;

3. Valve seat material: nitrile rubber, EPDM, fluorine rubber, silicone rubber, PTFE.

Ranges of application for manual butterfly valve:
It is widely used in the pipelines of petroleum, chemical, food, medicine, papermaking, hydropower, shipbuilding, water supply and drainage, metallurgy, oil, energy and other systems. It is suitable for a variety of corrosive gases, liquids, semi-liquid and solid powder media.

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

Uses and characteristics of manual butterfly valve (3)

July 21, 2020

Features of manual butterfly valve:
The butterfly valve opening and closing part is a disc-shaped butterfly plate, which rotates around its own axis in the valve body to achieve opening and closing or adjustment of the valve is called a butterfly valve. The butterfly valve is usually less than 900 from fully open to fully closed. The butterfly valve and the butterfly rod

Double flange butterfly valve (7)

themselves are not self-locking. For the positioning of the butterfly plate, a worm gear reducer must be installed on the valve rod. The use of worm gear reducer can not only make the butterfly plate have self-locking ability, make the butterfly plate stop at any position, but also improve the operation performance of the valve. Industrial-specific butterfly valves are characterized by high temperature resistance, high applicable pressure range, large nominal diameter of the valve, the valve body is made of carbon steel, and the sealing ring of the valve plate uses a metal ring instead of a rubber ring. Large high-temperature butterfly valves are manufactured by welding steel plates, and are mainly used for flue ducts and gas pipes for high-temperature media.

Advantages of manual butterfly valve:
The opening and closing is convenient and rapid, labor-saving, low fluid resistance, and can be operated frequently. Simple structure, small size and light weight. Mud can be transported, with the least accumulation of liquid at the pipe mouth. Under low pressure, good sealing can be achieved. Good adjustment performance.

Disadvantages of manual butterfly valves:
1. Use pressure and working temperature range are small.
2. Poor airtightness.

Classification of manufal butterfly valve:
According to the structure, it can be divided into offset plate type, vertical plate type, inclined plate type and lever type. According to the sealing form, it can be divided into two types: soft sealing type and hard sealing type. The soft seal type generally uses a rubber ring seal, and the hard seal type generally uses a metal ring seal. According to the connection type, it can be divided into flange connection and wafer connection; according to the transmission mode, it can be divided into manual, gear transmission, pneumatic, hydraulic and electric.

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

Butterfly valve and its Development history – (2)

July 8, 2020

China’s valve industry chain is numerous, but it is not a valve power. Generally speaking, my country has entered the ranks of the world’s valve power, but from the perspective of product quality, my country still has a long gap from the valve power. The low production concentration of the industry, the low R&D capacity of

TH valve products

valves supporting high-end products, and the low level of manufacturing technology in the valve industry still exist, and the import and export trade deficit continues to expand. There are absolutely not so many valve companies that can really survive in the market. However, this high-speed shock in the valve industry will bring huge opportunities, and the result of the shock will make the market operate more rationally. The road to localization of high-end valves is unusually bumpy. Basic parts have become a short board that restricts the development of my country’s manufacturing industry to high-end. During the 12th Five-Year Plan period, the government will continue to increase the localization of high-end equipment parts. Here we select a few key mentioned in the “Implementation Plan” to develop a representative valve industry for import substitution feasibility analysis. It can be seen from the analysis that the feasibility of valve import substitution in various sub-industries varies greatly, and high-end valves urgently need more policy guidance and scientific research support.

The valve industry plays an important role in the development of the national economy as an important link in the equipment manufacturing industry. Since China’s domestic valve manufacturing level still has a certain gap compared with the international advanced level, many high-parameter, high-temperature, high-pressure, and high-pound key valves have always relied on imports. Relevant state departments in accordance with the national requirements for major equipment localization, A series of major deployments have been made successively, and led by the National Development and Reform Commission, the China National Machinery Industry Federation and the China General Machinery Industry Association have deployed and formulated a valve localization plan for major equipment in related fields, and have coordinated with relevant departments many times. Localization has formed a consensus in the domestic valve industry. Actively adopt international standards for product design; absorb foreign excellent design structures (including patented technology); product testing and performance inspection are strictly in accordance with international standards; absorb foreign production process experience and attach importance to the research and promotion of new materials; understand the high imports The technical parameters and working conditions of valve products are the way to speed up the process of localization, promote the continuous updating of valve products, and fully realize the localization of valves. With the acceleration of the reorganization of the valve industry, the future industry will be the competition between the quality and safety of valve products and product brands. The products are developing toward high technology, high parameters, strong corrosion resistance, and long life. Only through continuous technological innovation, development New products and technical transformations can gradually improve the technical level of products, meet the domestic equipment, and fully realize the localization of valves. Under the huge demand environment, my country’s valve manufacturing industry will surely present a better development prospect.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China. It was founded in 2006. Its predecessor was Tanghai Valve Manufacturing Factory. 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. Our main products: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…),

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

Butterfly valve and its Development history – (1)

July 7, 2020

Butterfly valve, also known as flap valve, is a kind of simple structure regulating valve, which can be used for the on-off control of low-pressure pipeline medium; is a kind of valve that the closing part (flap or disc) is a round plate, which rotates around the valve axis to achieve opening and closing.

The valve 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.

U-type-flange-butterfly-valve-2

Mainly cut off and throttle the pipe. The opening and closing part of butterfly valve is a disc-shaped butterfly plate, which rotates around its own axis in the valve body, so as to achieve the purpose of opening, closing or adjusting.

The butterfly valve was invented in the United States in the 1930s and introduced to Japan in the 1950s. It was only widely adopted in Japan in the 1960s, but its promotion in my country was after the 1970s. The main characteristics of butterfly valves are: small operating torque, small installation space and light weight. Taking DN1000 as an example, the butterfly valve is about 2T, while the gate valve is about 3.5T, and the butterfly valve is easy to be combined with various driving devices, and has good durability and reliability. The disadvantage of the rubber seal butterfly valve is that when it is used for throttling, improper use will cause cavitation, which will cause the rubber seat to peel off and damage. Therefore, how to choose it correctly depends on the working conditions.

The relationship between the opening of the butterfly valve and the flow rate basically changes linearly. If it is used to control the flow, its flow characteristics are also closely related to the flow resistance of the piping. For example, the diameter and form of the valves installed in the two pipelines are the same, and the pipeline loss coefficients are different, and the flow rate of the valve

Double flange butterfly valve (16)

will also be very different. If the valve is in a large throttle range, the back of the valve plate is prone to cavitation, which may damage the valve. Generally, it is used

outside 15°. When the butterfly valve is in the middle opening, the opening shape formed by the valve body and the front end of the butterfly plate is centered on the valve shaft, and the two sides are formed in different states. The front end of the butterfly plate on one side moves in the direction of the water flow, and the other side counters the direction of the water flow. Therefore, the valve body and the valve plate on one side form a nozzle-shaped opening, and the other side resembles an orifice-shaped opening. The flow rate on the nozzle side is much faster than the throttle side, and negative pressure will occur below the throttle side valve, often The rubber seal will come off. The operating torque of a butterfly valve has different values depending on the degree of opening and the direction of valve opening and closing. Horizontal butterfly valves, especially large-diameter valves, due to water depth, the torque generated by the difference between the valve shaft and the water head can not be ignored. In addition, when the elbow on the inlet side of the valve forms a bias flow, the torque will increase. When the valve is in the middle opening, the operating mechanism needs to be self-locking due to the water flow torque.

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

Installation requirements for manual butterfly valves

July 2, 2012

1. Before installing the manual butterfly valve, do not throw it away at random. It needs to be placed in a cool, dry and ventilated environment, and it must be covered well to prevent the valve from being contaminated with dust and other debris, which affects the later use.

2. Before installing on the pipeline, the pipeline must be calibrated first. The positions of the pipelines at both ends must be

wafer-type-butterfly-valve-with-handle-13

consistent, and there must be no deviation. Otherwise, if the manual butterfly valve is installed when the pipeline deviates, it will cause tension on the valve body. Or the impact of rupture.

3. In addition to the calibration of the pipeline, there is another preparation before installation, that is, to clean the manual butterfly valve and its pipeline to ensure the cleanness of the valve and the pipeline, otherwise it will affect the sealing effect of the valve.

4. Manual butterfly valves require frequent manual operations. Therefore, the installation position of the manual butterfly valve is also very particular. The valve installation position must be convenient for personnel operation and future maintenance. It has been demonstrated that the best position for manual valve installation is about 1.2 meters on the operating floor. For valves installed outdoors, cover the valve with some covering to prevent the bad weather from affecting the valve.

5. During installation, the butterfly plate of the manual butterfly valve must be in the closed position to avoid collision damage of the butterfly plate and the pipeline flange, affecting the sealing performance.

6. After the installation is completed, commissioning should be carried out. If the manual butterfly valve has 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 tapping, prying, or brute force.

The installation requirements for manual butterfly valves are actually very simple. We need to pay attention to the details after the valve is purchased. Of course, the key to the safety of the pipeline and the service life of the valve lies in the correct selection and configuration.

Commonly used butterfly valves are wafer-type butterfly valves and flanged butterfly valves. Wafer type butterfly valve is to connect the valve between the two pipeline flanges with double-headed bolts. Flange type butterfly valve is to have a flange on the valve, and use bolts to connect the two ends of the valve to the pipeline flange. There are four types of butterfly valves in Tanghai Valve company, see below:

Butterfly Valve

Tianjin TanghaiDongyang Valve Co., Ltd. is one of the largest butterfly valve manufacturers in China. It was founded in 2006. Its predecessor was Tanghai Valve Manufacturing Factory. 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.

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

Structural characteristics of butterfly valve

May 24, 2012

The butterfly plate of the butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the valve body of the butterfly valve, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When it is rotated to 90°, the valve is fully opened.

The butterfly valve has a simple structure, small volume and light weight, and is composed of only a few parts. And only need to rotate 90 ° to quickly open and

U-type-flange-butterfly-valve-2

close, simple operation, and the valve has good fluid control characteristics. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the single resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small, so it has good flow control characteristics. There are two types of butterfly valve: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded on the valve body or attached to the periphery of the butterfly plate.

Valves with metal seals generally have a longer life-time than valves with elastic seals, but it is difficult to achieve complete sealing. Metal seals can adapt to higher operating temperatures, while elastic seals have the disadvantage of being limited by temperature.

If the butterfly valve is required to be used as a flow control, the main thing is to choose the valve size and type correctly. The structure principle of the butterfly valve is especially suitable for making large-diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, and water treatment, but also in cooling water systems of thermal power stations.

Commonly used butterfly valves are wafer-type butterfly valves and flanged butterfly valves. Wafer type butterfly valve is to connect the valve between the two pipeline flanges with double-headed bolts. Flange type butterfly valve is to have a flange on the valve, and use bolts to connect the two ends of the valve to the pipeline flange. There are four types of butterfly valves in Tanghai Valve company, see below:

Butterfly Valve

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China. It was founded in 2006. Its predecessor was Tanghai Valve Manufacturing Factory. 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.

Introduction of U-shaped flange butterfly valve

Uses and characteristics of manual butterfly valve (4)

Uses and characteristics of manual butterfly valve (3)

Butterfly valve and its Development history – (2)

Butterfly valve and its Development history – (1)

Installation requirements for manual butterfly valves

Structural characteristics of butterfly valve

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