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Stem structure and Integral Seat of centerline wafer butterfly valve

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

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

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

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

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

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

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

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

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

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

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valveball 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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Stem structure of centerline wafer butterfly valve
Reasons and solutions for leakage of valve sealing surface
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Centerline flange butterfly valve

How to install wafer butterfly valve and installation tips

Title: How to install wafer butterfly valve

In this article, let’s talk about the installation method of the wafer butterfly valve. Wafer type is a connection method of butterfly valve, that is, when installing on the pipeline, it is necessary to clamp the butterfly valve with two pieces of flanges, and then connect it with the flange on the pipeline. Corresponding to it is another connection method of butterfly valve, flange type. The installation of flanged butterfly valve will be shared with you in the future. Today we mainly talk about how to install the wafer butterfly valve in the form of pictures and texts.

JIS 10K-wafer butterfly valve-backup seat (4)

JIS 10K-wafer butterfly valve-backup seat (4)

The structure of the wafer butterfly valve is relatively short and takes up little space. During installation, use the special flange for the wafer butterfly valve to fix it, and then put the fixed wafer flange into the middle of the flanges at both ends of the pipeline, and use bolts to fix it. The control of the fluid medium in the pipeline can be realized by fixing it through the special flange of the wafer butterfly valve and the pipeline flange (if there is no flange on the pipeline, the special flange for the butterfly valve needs to be welded on the pipeline). The wafer type butterfly valve occupies a small space, which makes it especially suitable for installation and use in situations where the space is narrow or the distance between pipes is relatively small.
The specific installation steps of the wafer butterfly valve are as follows:
1. Place the wafer butterfly valve between the two pre-installed special flanges for wafer butterfly valves, and pay attention to align the flange bolt holes with the round holes of the butterfly valve body.

2. Insert the bolts and nuts into the flange holes to connect the valve body and the flange, and correct the flatness in the method, but be careful not to overtighten the bolts and nuts.

3. Weld the flange on the pipe, this step should be done by spot welding.

4. Remove the wafer butterfly valve first.

5. Weld the two flanges on the pipe completely to complete the fixation.

6. After the weld between the flange and the pipe is cooled, install the wafer butterfly valve. At this time, pay attention to opening the butterfly plate a little.

7. Correct the installation position of the butterfly valve again, and tighten the bolts, but be careful not to over-tighten them.

8. Fully open the butterfly plate of the butterfly valve to ensure that the butterfly plate of the butterfly valve can be opened and closed freely.

9. Cross the bolts again and tighten them evenly;

10. After the above steps are completed, test the opening and closing of the butterfly valve again to ensure that the valve can open and close freely.

The above is the introduction of butterfly valve installation steps. Here, I would like to tell all friends who purchase butterfly valves. Before installing the wafer butterfly valve, pay attention to the handling and do not bump it at will. After installation, non-professionals should not disassemble it casually.

Double offset-wafer butterfly valve-D72F-150lbC (1)

Double offset-wafer butterfly valve-D72F-150lbC (1)

Manual wafer butterfly valve installation skills

1. Storage work before installation: Store the manual wafer butterfly valve in a cool, dry and ventilated environment, and cover the valve to prevent the valve from being contaminated with dust and all debris.
2. Before the wafer butterfly valve is installed on the pipeline, the pipeline needs to be calibrated, and the positions of the pipes at both ends cannot be deviated. Body strain or rupture.
3. Before the valve is installed, the valve and all installed pipelines should be cleaned again to ensure that the inside of the valve and the pipeline is completely clean, and no dust is left.
4. Manual wafer butterfly valve belongs to manual butterfly valve, which requires frequent manual operation. Therefore, there are also requirements for the installation position of the manual butterfly valve. The installation position of the valve must be convenient for personnel to operate and maintain in the future. It has been demonstrated that the best position for manual valve installation is about 1.2 meters from the operating floor. For valves installed outdoors, cover the valve with some covering to prevent bad weather from affecting the valve.
5. When installing on the pipeline, make sure that the butterfly plate is in a closed state, so as to avoid collision and damage between the butterfly plate and the pipeline flange, which will affect the sealing performance.
6. After the manual wafer butterfly valve is installed, if there is 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 beating, prying or brute force.
The above is the whole content of the “manual wafer butterfly valve installation skills” introduced for you. Here, the editor also reminds everyone that after the valve is installed, it must be regularly maintained during the use of the valve. work, so as to ensure the normal and smooth operation of the valve. If you have purchase requirements for manual wafer butterfly valves, you are welcome to consult the official website of Tanghai 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

Video of center-lined butterfly valve:

Video of double eccentric butterfly valve:

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Pneumatic butterfly valve installation instructions
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Uses and characteristics of manual butterfly valve (4)

Sealing Surface Structure of Handle Wafer Type Butterfly Valve

The sealing surface structure of the handle wafer butterfly valve is the key to ensure the reliable sealing of the valve and an important basis for judging the performance of the valve. The sealing performance is related to whether the butterfly valve can perform normal adjustment and cut off the medium work. In general, the sealing surface is

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

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

composed of the valve seat and the disc of the wafer butterfly valve. It depends on the close contact between the valve seat and two or more precision-machined and ground sealing surfaces on the disc, or the sealing surface is produced by pressure. The sealing is achieved by plastic deformation.

The sealing surface of the handle wafer butterfly valve:
1. Resistant to medium corrosion;
2. Wear resistance and friction;
3. Ensure reliable sealing under the current working conditions;
4. Good processing technology;
5. Easy to assemble and maintain.

The sealing surface form of the handle wafer butterfly valve:
The sealing surface of the valve has several forms, including flat seal, cone seal, spherical seal, and knife seal. The handle wafer butterfly valve is mainly flat seal and spherical seal. The concept of flat seal is that the two contact surfaces of the seal are flat. Compared with several other sealing forms, the flat seal has its own unique advantages, the most important being the convenience of processing and repair. If it is used on the globe valve, it can also make the valve open and close without friction at the moment. Spherical seal means that one of the two contact surfaces of the seal is spherical. Butterfly valves with good sealing performance, ball valves and some small-diameter globe valves are used more. The advantage of the spherical seal is that the seal is larger and the sealing performance is good, but the disadvantage is that the maintenance is more difficult.
There are many fastening forms for the sealing surface of the handle wafer butterfly valve, which are mainly determined according to the conditions of the medium used, such as the pressure, temperature, corrosiveness of the medium, and the properties of the material of the sealing ring and the material of the housing. The basic requirements for the tightening of the valve sealing ring are that the joint surface has good sealing, easy processing, convenient maintenance, reliable connection and durability.

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

Video of center-lined butterfly valve:

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Introduction to the Features of Lever Wafer Butterfly Valve
The correct operation method of manual valve
Working principle and characteristics of triple eccentric butterfly valve

Application of Soft Seal Wafer Butterfly Valve in Sewage Treatment

The soft-seal wafer butterfly valve is now closely inseparable from various township sewage treatment plants. In the past agricultural villages, the sewage discharge facilities of farm households have not been transformed, resulting in the direct discharge of a large amount of domestic sewage, which seriously affected the lives of local villagers and

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

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

threatened the ecological environment of rivers and rivers. With President Xi’s idea that “green water and green mountains are golden mountains and silver mountains”, the overall management of the city’s urban domestic sewage and the strengthening of the city’s ecological civilization construction are highly valued. While the construction of the township sewage treatment plant is in full swing, it is the important role of the soft seal butterfly valve in the sewage treatment.
Sewage treatment valves are generally soft-sealed butterfly valves, seat-sealed elastic gate valves, etc. If the sewage is acidic, it may be necessary to use a lining valve. It is very important for us to select the appropriate type of the soft seal butterfly valve according to different working conditions, so that it can be better used in sewage treatment working conditions. For example, when the chloride ion content in the water is 700mg/L, both steel-lined 4F and ordinary carbon steel butterfly valves can be used, while butterfly valves made of 304 and 316 are not good under this working condition because they cannot resist corrosion well.
For another example, a situation that many engineering pipelines in the north can encounter is that due to the low temperature in winter, the properties of many materials change at low temperatures, resulting in the loss of equipment or components. If the soft-seal wafer butterfly valve made of gray iron is selected in this case and the warmth is not well maintained, the valve will easily be broken by freezing. The major reason for this situation is that the weather is not considered in the pipeline design, which makes the system work abnormally. If the buried pipeline is buried deep enough and the exposed pipe fittings are insulated in place, this type of loss can be reduced. In winter in the north, facilities such as pipelines and valves are easily damaged. In addition to the low-temperature performance of the materials, there is another important reason: the water in the pipeline or pump is frozen. In the case of the same quality, the volume of ice is larger than that of the water, pipeline or pump. If there is water, the valve can easily burst. Under such working conditions, the manufacturers of soft-seal butterfly valve suggest that water treatment in the north, except that the pipeline is buried under the frozen layer, should first be insulated before the pipeline enters water, and ensure that there is water flowing or Empty the water after parking. If there is no more water, be sure to drain the water in the pipe. Otherwise, as long as there is still water after parking, there will be freezing cracks from the weak points of the pipeline or butterfly valve.
In the enquiry reception of Tanghai Valve, we also received customer inquiries regarding municipal sewage treatment whether it would be better to choose imported soft-seal wafer butterfly valves, but our suggestion is generally that municipal sewage does not need to be imported. Because the imported price is expensive and the delivery period is long, domestic valve manufacturers can do it. Generally, the use conditions of valves in sewage treatment plant projects are relatively low, and domestic valves not only meet the needs of use, but also save costs. A better domestic factory can meet the requirements, but the design institute generally chooses imported brands according to the situation.

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

Video of center-lined butterfly valve:

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Gate valve has a broad market in the field of sewage treatment
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Information about stainless steel wafer butterfly valve

Stainless steel wafer butterfly valves are metal butterfly valves. Metal valves generally have a longer life than elastic sealing valves, but it is difficult to achieve a complete seal. The metal seal can adapt to higher working temperature, while the elastic seal has the defect of being limited by temperature.

The structure of stainless steel wafer butterfly valve

Double eccentric-wafer butterfly valve-D372F-150lbP-stainless steel (1)

Double eccentric-wafer butterfly valve-D372F-150lbP-stainless steel (1)

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. Stainless steel wafer 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. The commonly used wafer butterfly valve uses stud bolts to connect the valve between the two pipeline flanges. The flanged butterfly valve has a flange on the valve, and the two ends of the valve are flanged to the pipeline flange with bolts.

Installation of stainless steel wafer butterfly valve
The butterfly plate of the stainless steel wafer 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 axial direction, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is in a fully open state. The wafer 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 for the medium to flow through the valve body.

Classification of stainless steel wafer butterfly valves
According to the form, 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 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
Video of center-lined butterfly valve: https://youtu.be/NuSZH_AJcwY
Video of double eccentric butterfly valve: https://youtu.be/yOw2xp3bIaE
Video of triple eccentric butterfly valve: https://youtu.be/AkRwg2X1Wh0

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Product Features of Electric Wafer Butterfly Valve
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Product Features of Electric Wafer Butterfly Valve

The electric wafer butterfly valve belongs to a variety of electric control valves. Its connection methods are mainly: flange type and wafer type. Its sealing forms mainly include: soft seal and metal hard seal. The electric wafer butterfly valve controls the switching operation of the butterfly valve through the power signal, and can be used as the shut-off valve, control valve and check valve of the pipeline system. With manual control device, once there is a power failure, it can be temporarily operated manually without affecting the use. Now the electric wafer butterfly

Types of wafer butterfly valves

Types of wafer butterfly valves

valve has been continuously improved and upgraded, and the new electric wafer butterfly valve can be better used in working conditions.

The structural characteristics of a new type of electric wafer butterfly valve
1. It can still have stable sealing performance under high temperature and high pressure conditions. With a special sealing system to ensure high sealing performance in various temperature ranges from ultra-low temperature to ultra-high temperature
2. The eccentric electric wafer butterfly valve makes the valve opening resistance small. The sealing surface of the butterfly plate is an upwardly convex cone. When opening, all points on the circumferential surface of the butterfly plate are separated from the sealing ring at the same time, and solid objects are not easy to accumulate on the sealing surface. The valve closing process is completed by the elastic pressure of the sealing ring.
3. There is no interlocking phenomenon between the electric butterfly plate and the sealing ring. The sealing performance of the valve is not affected by temperature changes.
4. The butterfly valve stem is sealed with graphite pressed into a sealing ring to ensure zero leakage.

triple eccentric butterfly valve-wafer-lug-double flange-welded (5)

triple eccentric butterfly valve-wafer-lug-double flange-welded (5)

Features of the new electric wafer butterfly valve:
1. It adopts double eccentric structure, with tighter and tighter sealing function, and reliable sealing performance.
2. The sealing material is made of stainless steel and nitrile oil-resistant rubber pairing, which has a long service life.
3. The rubber sealing ring can be located on the valve body or on the butterfly plate, which can be applied to different characteristics of media for users to choose.
4. The butterfly plate adopts a frame structure with high strength, large flow area and small flow resistance.
5. In order to effectively prevent corrosion, the overall paint will be applied to facilitate the replacement of valve seat sealing materials for use in different media.
6. This valve has a two-way sealing function. It is not controlled by the flow direction of the medium during installation and is not affected by the spatial position. It can be installed in any direction.
7. It has the advantages of small size, light weight, reliable performance, simple matching, and large flow capacity, which is especially suitable for clean liquids and gases.

In the fierce market competition, manufacturers of electric wafer butterfly valves must adhere to the policy of developing enterprises through science and technology, continuously optimize product structure, and implement quality improvements. Increase the introduction of technology and form its own product characteristics. Providing high-quality products and satisfactory service is the tenet of Tanghai. We warmly welcome customers to inquire and patronize!

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

Video of center-lined butterfly valve: https://youtu.be/NuSZH_AJcwY
Video of double eccentric butterfly valve: https://youtu.be/yOw2xp3bIaE
Video of triple eccentric butterfly valve: https://youtu.be/AkRwg2X1Wh0
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Types of Sealing Material of Electric Wafer Butterfly Valve

Electric wafer butterfly valves can be divided into soft-sealed butterfly valves and hard-sealed butterfly valves, which are distinguished according to the sealing materials of electric butterfly valves.

triple eccentric butterfly valve-wafer-lug-double flange-welded (5)

triple eccentric butterfly valve-wafer-lug-double flange-welded (5)

The soft sealing butterfly valve’s sealing feature is that one side of the two sides is made of metal material, and the

other side is made of elastic non-metal material, that is, one of the valve seat and the valve plate is made of elastic material, which is called “soft seal” . The hard seal butterfly valve means that both sides of the seal pair are made of metal materials or other harder materials, that is, the valve seat and the valve plate are both hard materials, which is called “hard seal”.

The difference between soft seal and hard seal of electric wafer butterfly valve
Although the soft-sealed electric wafer butterfly valve has certain strength, hardness and temperature resistance, it has good sealing performance and can achieve zero leakage. But it is not resistant to high temperature, easy to wear, and has poor mechanical properties. Our common ones are steel + rubber, steel + PTFE and so on. The hard seal of the butterfly valve has poor sealing performance, but it is resistant to high temperature, abrasion and mechanical properties. Such as steel + steel, steel + copper, steel + graphite, steel + alloy steel. The steel here can be cast iron, cast steel, alloy steel or surfacing, sprayed alloy.

The advantages and disadvantages of the soft and hard seals of the electric wafer butterfly valve

In terms of sealing performance, the soft-seal electric wafer butterfly valve is relatively good, but compared with the hard-seal butterfly valve’s corrosion resistance, the soft-seal electric butterfly valve cannot meet the process requirements for corrosive materials. The advantage of the soft sealing 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

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

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

life. The hard-sealed butterfly valve has a long service life, but the sealing performance is relatively worse than that of the soft-sealed butterfly valve. Now there is a kind of multi-level sealing electric wafer butterfly valve that combines the advantages and disadvantages of soft sealing and hard sealing to form a complement to each other, which is a major upgrade of the product.

Different working conditions of soft and hard sealing of electric wafer butterfly valve
Let’s take a look at the different working conditions of the soft seal and the hard seal of the electric wafer butterfly valve from four aspects. The details are as follows:
1. Structure: soft-sealed electric wafer butterfly valves are mostly centerline butterfly valves, and hard-sealed electric wafer butterfly valves are mostly single eccentric butterfly valves, double eccentric butterfly valves, and triple eccentric butterfly valves.
2. Temperature resistance: soft-sealed electric butterfly valve is used in normal temperature environment. The hard-sealed electric butterfly valve can be used in low temperature, normal temperature, high temperature and other environments.
3. Pressure: The soft-sealed electric wafer butterfly valve can be used in low and normal pressure, and the hard-sealed electric butterfly valve can also be used in medium and high pressure conditions.
4. Sealing performance: The soft sealing electric butterfly valve and the triple eccentric hard sealing electric butterfly valve have better sealing performance. The triple eccentric butterfly valve can maintain a good seal under high pressure and high temperature environment.

Based on the above characteristics, the soft-sealed electric wafer butterfly valve is suitable for the two-way opening and closing and adjustment of ventilation and dust removal pipelines, water treatment, light industry, petroleum, chemical and other industries. Hard-sealed electric butterfly valves are mostly used in heating, gas, gas, oil, acid and alkali environments.

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

Video of center-lined butterfly valve:

Video of double eccentric butterfly valve:

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What are the characteristics of the soft sealing butterfly valve
Fluorine-lined butterfly valve vs metal seated butterfly valve
What are the characteristics of the hard seal butterfly valve
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Commonly used valve body materials of centerline wafer butterfly valve

The centerline butterfly valve can be controlled by a variety of transmission methods, such as manual, electric, hydraulic, pneumatic, turbine, electromagnetic, electromagnetic hydraulic, electro-hydraulic, pneumatic-hydraulic, spur gear, bevel gear drive, etc. Under the action of pressure, temperature or other forms of sensing signals, it can act according to predetermined requirements, or simply open or close without relying on sensing signals. The valve

Wafer type butterfly valve with worm gear

Wafer type butterfly valve with worm gear

relies on a drive or an automatic mechanism to make the opening and closing parts move up and down, sliding, swinging or rotating, thereby changing the size of the flow channel to achieve its control function. The centerline wafer butterfly valve is very suitable for the flow adjustment of the fluid, and it is also used as the opening and closing of the medium. It is a very common pipe fitting in the industrial field. Different valve body materials will be suitable for different centerline butterfly valve classifications.

The body materials of the centerline wafer butterfly valve mainly include:
Gray cast iron: suitable for low-pressure valves with a working temperature between -15 and +200°C and a nominal pressure of PN ≤ 1.6 MPa;
Black core malleable cast iron: suitable for low- and medium-pressure valves with a working temperature between -15 and +250°C and a nominal pressure of PN≤2.5MPa;
Nodular cast iron: suitable for medium and low pressure valves with a working temperature between -30 and +350°C and a nominal pressure of PN≤4.0MPa;
Carbon steel (WCA, WCB, WCC): suitable for medium and high pressure valves with operating temperature between -29 and +425°C, of ​​which 16Mn and 30Mn have operating temperatures between -40 and +450°C, often used to replace ASTMA105 ;
Low-temperature carbon steel (LCB): suitable for low-temperature valves and valves whose working temperature is between -46~+345℃;
Alloy steel (WC6, WC9): suitable for high temperature and high pressure valves for non-corrosive media with a working temperature between -29 and +595°C; WC5, WC12: suitable for corrosion at a working temperature between -29 and +650°C High temperature and high pressure valves for sexual media;
Austenitic stainless steel: suitable for valves with corrosive media whose working temperature is between -196~+600℃;
Monel alloy: mainly suitable for valves containing hydrogen and fluorine media;
Cast copper alloy: Mainly suitable for valves for oxygen pipelines whose operating temperature is between -273 and +200℃;

Listed above are the major categories of commonly used materials for valve bodies. In each category of material, there are many functional subdivisions for different pressure levels. In addition, the valve body materials include titanium alloy (titanium valve), aluminum alloy (aluminum valve); plastic (plastic valve); ceramic (ceramic valve) and so on. Therefore, when selecting the valve body material, the valve body material suitable for the working conditions should be determined according to different uses and different pressure levels.
The centerline wafer butterfly valve is a control component in the pipeline fluid conveying system. It is used to adjust the flow direction and flow of the medium, and has the functions of opening and closing and medium adjustment. There are many varieties and specifications, which are used to control the flow of various types of fluids such as water, steam, oil, gas, mud, various corrosive media, liquid metals and radioactive fluids, and occupy an important position in the entire valve system.

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

Video of center-lined butterfly valve:

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Resilient seated vs metal seated wafer butterfly valve

The soft-seal wafer butterfly valve contains two characteristics, one is that the sealing form is a soft seal, and the other is the connection method is a wafer. Wafer butterfly valves are divided into soft sealing butterfly valves and hard sealing butterfly valves. Soft seal means that one side of the butterfly valve sealing pair is made of metal

JIS 10K-wafer butterfly valve-backup seat (4)

JIS 10K-wafer butterfly valve-backup seat (4)

material, and the other side is made of elastic non-metal material. The advantage of the soft sealing wafer butterfly valve is that it is made of non-metallic materials with certain strength, hardness and temperature resistance. It has good sealing performance, but its service life and temperature adaptability are relatively poor. In contrast, the hard seal wafer butterfly valve is made of metal, which can meet the process requirements of some corrosive materials. The hard seal has a long service life, but the sealing performance is relatively worse than that of the soft seal. The main differences between the soft-seal wafer butterfly valve and the hard-seal wafer butterfly valve are as follows:
1. The difference in structure: soft-sealed butterfly valves are mostly centerline. Hard seal butterfly valves are mostly single eccentric, double eccentric and triple eccentric butterfly valves.
2. Temperature resistance: soft-sealed butterfly valves are mostly used in normal temperature environments. Hard seal butterfly valve can be used in low temperature, normal temperature, high temperature and other environments.
3. Pressure: The soft seal wafer butterfly valve is only used for low pressure to normal pressure, and the hard seal can also be used for working conditions such as medium and high pressure, which is more resistant to high pressure.
4. Sealing performance: The soft sealing and triple eccentric hard sealing butterfly valves have better sealing

Double eccentric-wafer butterfly valve-D372F-150lbP-stainless steel (1)

Double eccentric-wafer butterfly valve-D372F-150lbP-stainless steel (1)

performance. The triple eccentric butterfly valve can maintain good sealing under high pressure and high temperature environment.
In addition to the difference in product characteristics between the soft-seal wafer butterfly valve and the hard-seal wafer butterfly valve, their performance is also different, and they are used in different working conditions to adjust. The soft sealing wafer butterfly valve is suitable for the two-way opening and closing and adjustment of ventilation and dust removal pipelines, water treatment, light industry, petroleum, chemical and other industries. Hard-seal wafer butterfly valves are mostly used in heating, gas supply, and gas, oil, acid and alkali environments.
With the widespread use of the soft-seal wafer butterfly valve, its features of convenient installation, convenient maintenance, and simple structure become more and more obvious. Products have also been continuously upgraded. For example, the electric soft-seal wafer butterfly valve, pneumatic soft-seal wafer butterfly valve, etc., which have been continuously developed in recent years, are used in more and more occasions, and gradually began to replace the more expensive electric power with some limited functions. Gate valves, globe valves, etc.

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

Video of center-lined butterfly valve:

Video of double eccentric butterfly valve:

Related news/knowledge:
Characteristics of soft seal /resilient seated gate valves
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Is a gasket needed for installation of the resilient seated wafer butterfly valve?

Before understanding the problem of adding gaskets to the soft-seal wafer butterfly valve, let’s take a look at the main working conditions of the soft-seal wafer butterfly valve. It can be applied to water supply and drainage, gas pipelines such as food, medicine, chemical industry, petroleum, electric power, textile papermaking, etc. It is used for regulating flow and intercepting medium. And has certain standards, as follows:

Wafer type butterfly valve with worm gear

Wafer type butterfly valve with worm gear

Standards for soft-seal wafer butterfly valves:
Gauge manufacturing specification: GB/T 12238-2008
Construction length specification: GB/T 12221-2005
Connection flange specification: GB/T 9113
Pressure temperature rating: GB/T 12224-2005
Experimental inspection specification: GB/T 13927-2008
The soft-seal wafer butterfly valve is characterized by sensitive operation, labor-saving, and good sealing performance. So the reason for choosing the soft-seal wafer butterfly valve to a large extent is because of its good sealing performance. Then, in actual field application, we encountered a problem: Can the connecting surfaces on both sides of the soft-seal wafer butterfly valve function as a flange gasket? When installing the butterfly valve, is it necessary to add gaskets for sealing? With such a question, let’s first look at a live case.
A new batch of soft-seal wafer butterfly valves from a factory are used for acidic liquid pipelines. The soft-seal of the product is made very thick, and some of the soft-seal material is exposed to form a convex surface. May I ask if this kind of butterfly valve is installed? Also add gaskets for sealing? Through practice, we have seen that this situation can be added or not, but it is added for more insurance. Generally, new soft-sealed butterfly valves can be sealed without gaskets. If it is an old valve, it is necessary to consider the problem of aging. Soft-seal butterfly valves generally come with a gasket, which can not be installed, but it depends on the application of the soft-seal wafer butterfly valve. For example, in this case, if it is used in high temperature or corrosive liquid pipelines, in order to avoid personal injury, it is recommended to add high-pressure PTFE gaskets during flange connection, so that it can be safer and can be done once and for all. The purpose of adding gaskets is to protect the rubber-lined flange surface, because the replacement valve ring is more expensive than the replacement valve gasket. If the gasket is not added under bad working conditions, even if the flange does not leak, it is very likely that the valve will leak internally.
So in summary, whether the soft seal wafer butterfly valve needs to be gasketed depends on the chemical nature, temperature and pressure of the pipeline medium. Generally speaking, although the connecting surfaces on both sides of the soft seal wafer butterfly valve can play the role of flange gasket, it is recommended to add a gasket on both sides for safety. Because the butterfly valve will bump and bump a little during transportation and handling, it will produce an incomplete sealing surface, so it is recommended to add an extra gasket. Of course, there are other points of view that there is no need to add shims, and it is superfluous. Therefore, we can refer to a standard and then make a choice according to our specific working conditions, which can be based on the valve diameter, etc.: soft-seal wafer butterfly valves under 6 kg may not be added; 6-16 kg butterfly valves are recommended to add gaskets. Spacers below DN300 are 1.5mm; spacers above DN300 and below 1200 are 3.0mm. For more butterfly valve information, please contact Tanghai Valve’s online customer service.

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

Video of center-lined butterfly valve:

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Characteristics of soft seal /resilient seated gate valves
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