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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

electric wafer butterfly valve vs electric flange butterfly valve

July 27, 2021

The difference and selection of electric wafer butterfly valve and electric flange butterfly valve
As one of the most common valves in pipelines, electric butterfly valves are used to realize the on-off and flow control of various media in the pipeline system. They have been widely used in many fields such as petroleum, chemical industry, metallurgy, and hydropower. application. Then in the commonly used electric butterfly valve, it can be

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

divided into two kinds, electric wafer butterfly valve and electric flange butterfly valve, and these two kinds of valves have their own characteristics, and they are not the same in performance. They can be used in Different industries.

For these two kinds of valves, in addition to the different structural forms, if they are under the same parameters, the biggest difference is that the connection method is different, that is, the installation form is different, which depends on the site working conditions!

The difference between electric wafer butterfly valve and electric flange butterfly valve:
The thickness of the electric wafer butterfly valve is relatively thin compared to the flanged butterfly valve. There are no flanges at both ends of the valve body, but only a few guide bolt holes. The valve uses a set of bolts/nuts to connect with the flange of the pipe end, which is generally applicable. It is used in places where the space is relatively narrow or the pipeline is restricted. The advantage is that it is more convenient to disassemble, the valve cost is lower, and the space is small, but the disadvantage is that one sealing surface has a problem, and both sealing surfaces have to be disassembled!
Electric flange butterfly valve has flanges at both ends of the valve body, which are connected with pipeline flanges. Compared with wafer butterfly valves, the sealing performance is more reliable. It is generally used in places with larger diameters or higher pressures, but the cost is relatively good.

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

Choice between the two:
However, there are still some things to pay attention to in the design. For example, wafer type valve bolts are generally relatively long. Under high temperature conditions, the expansion of the bolts may cause leakage, so it is not suitable for large pipe diameters under high temperature conditions. . Another example is the wafer butterfly valve generally cannot be used in the end of the pipeline and downstream needs to be disassembled, because when the downstream flange is removed, the wafer valve will fall off, in this case, it must be shortened separately. The flange type butterfly valve does not have the above problems, but the cost will be higher.
Related Electric butterfly valve series products View other butterfly valves

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

Fluorine-lined butterfly valve vs metal seated butterfly valve

July 23, 2021

The difference and selection of fluorine-lined butterfly valve and metal seated butterfly valve
As one of the most commonly used valves in process pipelines, butterfly valves are not only simple in structure, easy to operate, and equipped with different driving devices, but also can form a variety of control methods, such as electric butterfly valves, hydraulic butterfly valves, pneumatic butterfly valves, etc.! Moreover, butterfly valves are often used in occasions with large caliber and flow. Compared with other valves of the same caliber, the cost can be reduced by 1.5 to 2 times, which is economical and practical!

Fluorine lined butterfly valve-PTFE-DOUBLE FLANGE (2)

According to the different sealing forms of butterfly valves, they can be divided into two categories, one is soft seal and the other is metal seated! The two butterfly valves with different sealing forms play different roles in the relatively used pipelines. In a sense, there are still big differences! When choosing, users should have a detailed understanding and awareness of the difference between the two!

Take the most common soft-sealed fluorine-lined butterfly valves and metal hard-sealed butterfly valves, fluorine-lined butterfly valves are generally used for pipelines containing corrosive media, and the sealing effect can reach zero leakage, but it is only suitable for normal temperature and pressure! The hard-sealed butterfly valve is relatively high in temperature and pressure, but the sealing and corrosion resistance are not as good as the soft-sealed butterfly valve!
1. From the structure: The metal seated butterfly valve refers to the metal material or other harder materials on both sides of the sealing pair. For soft sealing butterfly valves, the two contacting sealing surfaces can be separate or all of soft materials. For example, fluorine-lined butterfly valve means that the butterfly plate and valve seat are both wrapped in PTFE;

triple offset butterfly valve-double flange- (5)

2. In terms of sealing performance: The advantage of the soft-sealed fluorine-lined butterfly valve is that it has good sealing performance, but the disadvantage is that it is easy to age, wear, and has a short service life. The metal seated butterfly valve has a long service life, but the sealing performance is relatively worse than that of the soft seal.
3. From the conditions of use: The soft-sealed fluorine-lined butterfly valve is used in normal temperature and pressure environments, while the hard-sealed butterfly valve can be used in low temperature, normal temperature, high temperature and other environments. Generally, it can be used for higher pressure, but the soft seal is not. However, the fluorine-lined butterfly valve has Super corrosion resistance!
4. From the manufacturing aspect: As for the manufacturing, from the principle point of view, the difference between the two is not big, mainly the difference in the valve seat. The soft-sealed fluorine-lined butterfly valve is a non-metallic structure, and the hard-sealed butterfly valve is a metal structure. It is necessary to consider the metal structure. The relationship between the hardness, the working conditions, what medium is used, and so on.

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 structure principle and application analysis

July 21, 2021

Butterfly valve (also called flap valve) is a kind of regulating valve whose closing part is circular disc or disc, mainly composed of valve body, valve stem, disc and sealing ring. The valve body is cylindrical with short axial length and built-in butterfly plate. The butterfly plate of the 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.

Double offset-flanged butterfly valve-D42F-150lbC (1)

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 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 inlaid on the valve body or attached to the periphery of the butterfly plate.
Butterfly valves with metal seals generally have a longer life than those with elastic seals, but it is difficult to achieve a complete seal. The metal sealing butterfly valve can adapt to higher working temperature, while the elastic sealing butterfly valve has 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 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 used in cooling water systems of thermal power stations.

Double eccentric-lug butterfly valve-D72F-150lbP-stainless steel (4)

Commonly used butterfly valves include wafer type butterfly valves and flange type 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.

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 fluorine-lined butterfly valve vs pneumatic hard-sealed butterfly valve

June 16, 2021

The difference between pneumatic fluorine-lined butterfly valve and pneumatic hard-sealed butterfly valve
Pneumatic butterfly valve is an important execution unit with relatively large usage in industrial pipelines. Compressed air is used as the power source to operate the valve opening and closing, and the execution speed is very fast, usually only a few seconds! Pneumatic butterfly valve has simple structure, convenient operation and low cost. It can not only be used for quick shut-off, but also can be matched with valve positioner to receive relevant signals to achieve adjustment and control of pipeline medium pressure, flow, temperature and other parameters!

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

There are many types of pneumatic butterfly valves, which can fully meet the requirements of various working conditions, and can also customize the required butterfly valve products according to customer needs. Pneumatic fluorine-lined butterfly valve and pneumatic hard-sealed butterfly valve are two commonly used types. The medium and pressure temperature used are different. The control mode of the two is the same, but the sealing structure is completely different. Pneumatic fluorine-lined butterfly valve is suitable For pipelines that require sealing and contain corrosive media, but the pressure and temperature should not be too high, pneumatic hard-sealed butterfly valves can be used in various pressure and temperature ranges, with long service life, but poor sealing effect!

1. From the structure:
The hard sealing butterfly valve refers to that both sides of the sealing pair are made of metal materials or other harder materials. For soft sealing butterfly valves, the two contacting sealing surfaces can be separate or all of soft materials. For example, fluorine-lined butterfly valve means that the butterfly plate and valve seat are both wrapped in PTFE;
2. From the sealing performance:

Fluorine lined butterfly valve-PTFE-WAFER (8)

The advantage of soft-sealed fluorine-lined butterfly valve is good sealing performance, but the disadvantage is that it is easy to age, wear, and has a short service life. The hard seal butterfly valve has a long service life, but the sealing performance is relatively worse than that of the soft seal.
3. From the conditions of use:
The soft-sealed fluorine-lined butterfly valve is used in normal temperature and pressure environment, and the hard-sealed butterfly valve can be used in low temperature, normal temperature, high temperature and other environments. Generally, it can be used for higher pressure, but the soft seal is not. However, the fluorine-lined butterfly valve has super corrosion resistance!
4. From the manufacturing point of view:
As for manufacturing, from a principle point of view, there is little difference between the two, mainly the difference in valve seats. The soft-seal fluorine-lined butterfly valve is a non-metallic structure, and the hard-seal butterfly valve is a metal structure. The hardness relationship between metals and the workmanship must be considered. Situation, what medium to go and so on. The choice between pneumatic fluorine-lined butterfly valve and pneumatic hard-sealed butterfly valve is mainly based on the process medium, temperature and pressure. Generally, the medium contains solid particles and is worn, or the temperature is higher than 200 degrees. It is best to choose hard-sealed butterfly valves!
Related knowledge: Pneumatic butterfly valve working principle diagram; Pneumatic butterfly valve model compilation method

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

Wafer butterfly valve installation instructions and steps

June 10, 2021

Wafer butterfly valve is one of the most common types of valves in industrial pipelines. The wafer butterfly valve itself has a relatively small structure. You only need to put the butterfly valve in the middle of the flanges at both ends of the pipeline, and use stud bolts to pass through the pipeline flange and the The clip-on butterfly valve is locked to control the fluid medium in the pipeline. Wafer butterfly valve is especially suitable for places with narrow space or short distance between pipelines. When the 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. Therefore, the pressure drop generated by the valve is very high. Small, so it has better flow control characteristics.

wafer type butterfly valve, with handle (13)

1. Instructions before installation of wafer butterfly valve:
1. Before installation and operation, use air spray to remove foreign objects on the piping, and clean the inner surface of the piping with clean water.
2. Carefully check whether the valve usage is consistent with its performance specifications; (temperature, pressure)
3. Check the valve channel and sealing surface for debris, and remove it in time;
4. The valve must be installed in time after unpacking, please do not loosen any fastening screws or nuts on the valve at will;
5. Wafer butterfly valves must use special butterfly valve flanges.
6. The electric butterfly valve can be installed on the pipeline at any angle. For the convenience of maintenance, it is recommended not to install it upside down.
7. When installing the butterfly valve flange, it must be ensured that the flange surface and the sealing rubber are aligned, the screws are evenly tightened, and the sealing surface must fit completely; if the screw tightening force is uneven, the rubber bumps will block the butterfly plate, or the top Staying on the butterfly plate causes leakage at the valve stem. To
2. The installation steps of the wafer butterfly valve: The correct installation of the wafer butterfly valve is related to the sealing degree of the butterfly valve, and whether it will leak or not, including the safety in working conditions. The user should understand the installation process.

wafer & lug type butterfly valve (7)

1. As shown, place the valve between the two pre-installed flanges, paying attention to the alignment of the bolt holes.
2. Gently insert four pairs of bolts and nuts into the flange holes, and tighten the nuts slightly to correct the flatness of the flange surface;
3. Fix the flange to the pipeline by spot welding;
4. Remove the valve;
5. Fully weld and fix the flange on the pipeline;
6. Install the valve after the welding port has cooled down. Ensure that the valve has enough space in the flange to prevent the valve from being damaged, and ensure that the valve plate has a certain degree of opening;
7. Correct the valve position and tighten the four pairs of bolts (be careful not to over tighten)
8. Open the valve to ensure that the valve plate can be opened and closed freely, and then slightly open the valve plate;
9. Tighten all nuts in cross balance;
10. Reconfirm that the valve can open and close freely. Note: Confirm that the valve plate does not touch the pipeline.
The installation of the wafer butterfly valve must be laid flat before installation, remember not to bump it at will, after it is drawn to the installation length during installation, in the design of the on-site pipeline, it is not possible without special permission Disassemble the wafer butterfly valve at will, this is what we need to know before installation. At the same time, everyone should know that the wafer butterfly valve can be installed in any position, but after the wafer butterfly valve is installed, the butterfly valve needs to be laid along the line, and a bracket is made for the wafer butterfly valve. Once the bracket is made, it will be used At that time, it is strictly forbidden to remove the bracket.
Related products: Electric wafer butterfly valve Pneumatic wafer 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

The advantages and disadvantages of butterfly valves

July 10, 2020

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)

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

Posts

Pneumatic butterfly valve working principle diagram

electric wafer butterfly valve vs electric flange butterfly valve

Fluorine-lined butterfly valve vs metal seated butterfly valve

Butterfly valve structure principle and application analysis

pneumatic fluorine-lined butterfly valve vs pneumatic hard-sealed butterfly valve

Wafer butterfly valve installation instructions and steps

The advantages and disadvantages of butterfly valves

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