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The advantages and disadvantages of butterfly valves

Advantages of butterfly valve:

1. Convenient opening and closing, labor saving, low fluid resistance, and can be operated frequently.

wafer type butterfly valve, NBR seat (11)

wafer type butterfly valve, NBR seat (11)

2. The structure is simple, the external dimensions are small, the structural length is short, the volume is small, and the weight is light. It is suitable for valves with large diameter.

3. Mud can be transported, and the least liquid is accumulated in the pipe mouth.

4. Under low pressure, a good seal can be achieved.

5. Good adjustment performance.

6. When fully opened, the effective flow area of the valve seat channel is large, and the fluid resistance is small.

7. The opening and closing torque is small, because the butterfly plates on both sides of the rotating shaft are basically the same under the action of the medium, and the direction of generating torque is opposite, so the opening and closing are more labor-saving.

8. The sealing surface material is generally rubber, plastic, so the low-pressure sealing performance is good.

9. Easy installation.

10. Flexible and labor-saving operation, you can choose manual, electric, pneumatic, hydraulic mode.

Disadvantages of butterfly valve:

1. The operating pressure and operating temperature range are small.

2. Poor sealing.

Butterfly valves can be divided into offset plate type, vertical plate type, inclined plate type and lever type according to the structure.

According to the sealing form, it can be soft-sealed or hard-sealed. The soft seal type generally uses a rubber ring seal, and the hard seal type usually 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 valvegate valvecheck valveglobe valveknife 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: What is the material of the main parts of the butterfly valve?-(2); Characteristics and working principle of electric globe valve; Classification and advantages of gate valve

Structure and characteristics of butterfly valve

Butterfly valve is mainly composed of valve body, valve stem, butterfly plate and sealing ring. The valve body is cylindrical, with a short axial length and a built-in butterfly plate.

Double flange butterfly valve (16)

Double flange butterfly valve (16)

Features of butterfly valve:
1. The butterfly valve has the characteristics of simple structure, small size, light weight, low material consumption, small installation size, rapid switching, 90° reciprocating rotation, and small driving torque. It is used to cut off, connect, and adjust the medium in the pipeline. Has good fluid control characteristics and closed sealing performance.

2. The butterfly valve can transport mud and has the least liquid accumulation at the pipe mouth. At low pressure, a good sealing effect can be achieved. Good adjustment performance.

3. The streamlined design of the butterfly plate makes the fluid resistance loss small, which can be described as an energy-saving product.

4. The valve stem is a through-rod structure. After quenching and tempering, it has good comprehensive mechanical properties, corrosion resistance and scratch resistance. When the butterfly valve is opened and closed, the valve stem only rotates and does not move up and down. The filler of the valve stem is not easy to damage and the seal is reliable. It is fixed with the taper pin of the butterfly plate, and the outgoing end is designed to prevent the outgoing type, so as to prevent the valve rod from collapsing when the connection between the valve rod and the butterfly plate is accidentally broken.

5. Connection methods include flange connection, wafer connection, butt welding connection and lug wafer connection. The driving form includes manual, worm gear transmission, electric, pneumatic, hydraulic, electro-hydraulic linkage and other actuators, which can realize remote control and automatic operation.

You can check the types and structures of butterfly valve on this page: Butterfly Valve

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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:
Classification and advantages of gate valve;
Classification and introduction of pipe thread-(3);
7 types of flange sealing surface: FF, RF, M, FM, T, G, RTJ;

How does a butterfly valve work?

A butterfly valve is a valve that uses a disc-type opening and closing part to reciprocate around 90° to open, close, or regulate the flow of media. Butterfly valves are not only simple in structure, small in size, light in weight, low in material consumption, small in installation size, small in driving torque, easy in operation and fast, but also can have good flow adjustment function and close sealing characteristics at the same time. One of the fastest valve varieties. Butterfly valves are one of the fastest growing valve varieties in the past decade.

Butterfly valves are widely used. The variety and quantity of its use are still continuing to expand, and develop to high temperature, high pressure, large diameter,

Double flange butterfly valve (16)

Double flange butterfly valve (16)

high sealing, long life, excellent adjustment characteristics, and multi-function development of one valve. Its reliability and other performance indicators have reached a high level. With the application of chemically resistant synthetic rubber on butterfly valves, the performance of butterfly valves has been improved. Because synthetic rubber has the characteristics of corrosion resistance, erosion resistance, dimensional stability, good resilience, easy forming, and low cost, and can choose different performance synthetic rubber according to different use requirements to meet the working conditions of butterfly valves.

Polytetrafluoroethylene (PTFE) has strong corrosion resistance, stable performance, not easy to aging, low friction coefficient, easy to form, stable in size, and can be filled and added with appropriate materials to improve its comprehensive performance, resulting in better strength and friction coefficient The lower butterfly valve sealing material overcomes the limitations of synthetic rubber. Therefore, polymer polymeric materials represented by PTFE and its filling modified materials have been widely used in butterfly valves. Therefore, the performance of butterfly valves has been further improved, resulting in a wider temperature and pressure range and sealing performance, reliable and longer life butterfly valve.

butterfly valve working diagram-3D GIF animated presentation

butterfly valve working diagram-3D GIF animated presentation

In order to meet the requirements of industrial applications such as high and low temperature, strong erosion, and long life, metal seal butterfly valves have been greatly developed. With the application of high temperature resistance, low temperature resistance, strong corrosion resistance, strong erosion resistance, and high strength alloy materials in butterfly valves, metal sealed butterfly valves have been widely used in industrial fields such as high and low temperature, strong erosion, and long life. The emergence of butterfly valves with large diameter (9~750mm), high pressure (42.0MPa) and wide temperature range (-196~606℃) has brought the technology of butterfly valves to a whole new level.

When the butterfly valve is fully opened, it has a small flow resistance. When the opening is between about 15°~70°, the sensitive flow control can be performed, so the application of butterfly valves is very common in the field of large-diameter adjustment. Because the movement of the butterfly plate of the butterfly valve is wiping, most butterfly valves can be used for media with suspended solid particles. Depending on the strength of the seal, it can also be used in powder and granular media. Butterfly valves are suitable for flow regulation. Because the pressure loss of the butterfly valve in the pipe is relatively large, about three times that of the gate valve, when selecting the butterfly valve, the influence of the pressure loss of the pipeline system should be fully considered, and the strength of the butterfly plate to withstand the pressure of the pipeline medium when closing . In addition, the working temperature limit of the elastic seat material must be considered at high temperatures.

The structure length and overall height of the butterfly valve are small, the opening and closing speed is fast, and it has good fluid control characteristics. The structure principle of butterfly valve is most suitable for making large-diameter valve. When the butterfly valve is required for flow control, the most important thing is to correctly select the size and type of the butterfly valve so that it can work properly and effectively. Generally, in throttling, regulating control and mud medium, the structure length is short, the opening and closing speed is fast, and cut off at low pressure (small pressure difference). It is recommended to use a butterfly valve. Butterfly valves can be used when there are two-position adjustment, reduced diameter channels, low noise, cavitation and vaporization, a small amount of leakage into the atmosphere, and abrasive media.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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 /knowledges: Introduction of U-shaped flange butterfly valve; The working principle of butterfly valve (picture)

Butterfly valve and its Development history – (2)

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

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 valvegate valvecheck valveglobe valveknife 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 /products:
Industry development prospects of check valve;
working principle of electric globe valve;
Knowledge;
Butterfly valve and its Development history – (1);

Butterfly valve and its Development history – (1)

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

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)

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 valvegate valvecheck valveglobe valveknife 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: The main classification methods of butterfly valve (1); Detailed introduction of soft sealing butterfly valve-(3)

How to achieve internal and external anti-corrosion of pneumatic valves

Pneumatic valve using pneumatic actuators, for which Air (or other gas) pressure is the source of power. Air pressure acts on the piston or bellows diaphragm, which produces a linear force on the valve stem. Pneumatic actuator is a kind of Power-operated actuators (using pneumatic, hydraulic or electric power), can remotely adjust valves, or quickly operate large valves.

In order to effectively guarantee the use efficiency of the pneumatic valve, and also to effectively extend the service life of the pneumatic valve, the internal and

Pneumatic actuator (2)

Pneumatic actuator (2)

external corrosion protection of the pneumatic valve is a very important part of its use process, then we should pay attention to the main points for the internal and external corrosion protection of the pneumatic valve And what are the main items in the operation, we will give a brief introduction to you in the following article.

1. The inside of the valve body of the pneumatic valve and all parts of the valve plate require comprehensive corrosion protection. On the one hand, it will not rust in water, and there will be no electrochemical corrosion between the two metals; on the other hand, the smooth surface reduces the resistance to water.

2. Hygienic requirements of epoxy resin or paint for anti-corrosion of pneumatic valve body shall have a test report from corresponding authority. The chemical and physical properties should also meet the relevant requirements.

3. The inside and outside of the valve should first be shot blasted to remove sand and rust, and strive to

pneumatic valve structure

pneumatic valve structure

electrostatically spray powdered non-toxic epoxy resin with a thickness of more than 0.3mm. When it is difficult to electrostatically spray non-toxic epoxy resin for extra large valves, similar non-toxic epoxy paint should also be brushed and sprayed.

In addition, the pneumatic valve should also pay attention to the necessary maintenance during daily storage and transportation, including:

1. The pneumatic valve should be stored in a dry and ventilated room, and both ends of the passage must be blocked.
2. Valves stored for a long period of time should be checked regularly to remove dirt and apply anti-rust oil on the processed surface.
3. After the pneumatic valve is installed, regular inspections should be carried out. The inspection items are as

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

follows:
1) The wear of the sealing surface;
2) Trapezoidal thread wear of the stem and stem nut;
3) Whether the packing is out of date and invalid, and if damaged, it should be replaced in time.

TH Valve is one of the largest butterfly valve, check valve manufacturers in China. 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 valvegate valvecheck valveglobe valveknife 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 /knowledges:
Comparison of pneumatic actuator, electric actuator and hydraulic actuator;
Prevention and treatment of valve corrosion;
Pneumatic ball valve installation instructions;
Pneumatic butterfly valve working principle diagram;

Slow-closing design of stainless steel swing check valve

1. Structural improvement of swing check valve
A slow closing auxiliary valve is added on the flap of the original swing check valve. The auxiliary valve is installed on the lower side or both sides of the main valve

double-wing-check-valve-3

double-wing-check-valve-3

flap and is connected by threads. When the medium flow valve is opened, the medium pressure opens the auxiliary valve, and the medium flows into the main valve outlet through the small valve orifice, so that the main valve inlet end When the pressure is relieved, the valve flap of the main valve opens, and the pressure before and after the main valve tends to balance; when the medium reverses flow, the valve flap of the main valve closes quickly under the action of the reverse flow medium, and the upper part of the auxiliary valve body is a buffer cylinder, and the auxiliary valve cover is screwed into the valve.

There is a small hole on the cover of the upper part of the body. There is a certain gap between the valve flap of the auxiliary valve and the piston rod. The O-ring rubber seal is used between the piston and the buffer cylinder. The flat seal between the lower part of the piston and the valve flap; When the flap is closed with the main valve flap closed, the medium gradually flows into the upper chamber of the auxiliary valve buffer cylinder through the small hole due to the small hole of the auxiliary valve cover, and part of the medium flows back through the gap between the auxiliary valve flap and the piston rod Therefore, the auxiliary valve piston is closed slowly. In this structure, the closing of the main valve is equivalent to the fast closing stage, and the slow closing of the auxiliary valve is equivalent to the slow closing stage. According to the hydraulic and mechanical transition mechanism of the pump station unit, the structure design can effectively prevent the water hammer from boosting.

2. Improvement of lift check valve structure
The lifting check valve, also known as the bottom valve, can maintain the water column required for pumping when the pump is stopped; the feature of the valve structure improvement is that a slow closing auxiliary valve is added between the main valve flap and the valve body bracket as shown.

 lift-swing-check-valve-2

lift-swing-check-valve-2

A gasket ring is added between the valve body and the bottom net to increase the height of the valve flap. The buffer piston and the buffer cylinder are sealed with rubber. The valve flap shaft and the piston are rigidly connected, and the gap between the buffer cylinder and the valve flap shaft is small. When the medium flows downstream, the pressure medium pushes the valve flap into the main valve body cavity, and at the same time pushes the buffer piston upward; when the medium flows backward, the buffer cylinder is fully filled with the medium when it is opened, and the gap between the buffer cylinder and the valve disc shaft is relatively large. It is small, so as the medium in the buffer cylinder is gradually discharged through the gap, the main valve flap closes to play a buffering role, so that the water hammer boost in the pipe network can be controlled.

3. Test results before and after the improvement of the check valve slow closing structure
A calibrated pressure gauge is used, and the pressure signal is sent to the oscilloscope for recording by the differential pressure transmitter, and the water hammer pressure change value at each moment is read on the oscillogram with the calibrated ratio R.
The test valve has a diameter of 100mm, a system pressure of 0.5MPa, and a flow rate of 5L/s. When the pump stops suddenly, it shows the pressure-time curve of the inlet side of the check valve after the power is cut off
(1) The main valve flap opens and closes smoothly, the slow-closing auxiliary valve has a compact structure and reliable performance.
(2) The valve flap of the main valve closes first and then closes slowly, which can effectively prevent destructive water hammer and expand the use range of the check valve.
(3) The improved structure is simple and easy to produce and interchange.
(4) The slow-closing auxiliary valve can be repaired or replaced without hindering the use of the check valve.

The check valve is a valve that opens when the pipeline system is downstream and closes when it is upstream. It is mainly used to prevent backflow of the medium, prevent the pump and drive motor from reversing, and release the medium in the container. The rotary check valve with the shaft rotating and the lift check valve moving along the vertical center line of the valve body, but the valves of the above two structures both have the medium backflow speed rapidly reduced from the maximum to zero when the valve is closed, causing the pipeline The internal pressure on the side of the water inlet pipe rises rapidly, resulting in a water hammer phenomenon that has a destructive effect on the pipeline system, so the general check valve production caliber is 50 to 500 mm. In order to reduce the water hammer effect of the check valve and expand the range of use of the check valve, on the basis of the original product, a slow closing auxiliary valve was added to solve the problem of pipeline water hammer boosting.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve, check valve manufacturers in China. After 14+ years of continuous development and innovation, the company now has a group of high-tech engineers, technicians and skilled production workers, advanced production technology, sophisticated manufacturing equipment, complete testing methods, in strict accordance with international standards and quality management system, formed A comprehensive quality control network.

Related news/knowledges: Working principle diagram of lift check valve; Introduction of cast steel lift swing check valve

Installation requirements for manual butterfly valves

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

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 valvegate valvecheck valveglobe valveknife 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:
Uses and characteristics of manual butterfly valve (4);
Uses and characteristics of manual butterfly valve (3);
Uses and characteristics of manual butterfly valve (2);
What are the main factors affecting valve sealing?

Structural characteristics of butterfly valve

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

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.

Related news: The structural characteristics and uses of the wafer butterfly valve; What is a wafer type butterfly valve;

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