butterfly valve Archives

How to extend the service life of stainless steel metal seated butterfly valve

November 12, 2021

In general, we are most worried about the problem of stainless steel metal seated butterfly valves is rust. This is the common concern of the majority of users for metal products. In fact, stainless steel material itself is not easy to rust, but stainless steel materials are also divided into five categories, such as ferritic stainless steel, martensitic stainless steel, austenitic stainless steel, austenitic-ferritic stainless steel and precipitated carbide stainless steel. The

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

austenitic stainless steel has good corrosion resistance after normal heat treatment and will not rust easily. If the stainless steel butterfly valve rusts in normal use, it is mostly due to the precipitation of carbides along the grain boundary in the material to form a chromium-depleted zone, which causes the stainless steel hard-seal butterfly valve to rust.
Let’s take a look at what specific maintenance methods we should maintain during use in order to effectively avoid corrosion of the stainless steel metal seated butterfly valve and prolong its service life:
1. The stainless steel metal seated butterfly valve should be cleaned frequently during use, and the transmission device should be maintained and lubricated. Frequently troubleshoot faults in order to find faults and clear them in time.
2. The packing should be evenly packed and the cover should be tightened to prevent the medium from leaking from the packing for a long time and rust.
3. Pay attention to the connection method and direction of the valve to prevent leakage and erosion caused by misalignment.
4. The stainless steel metal seated butterfly valve is only used for adjustment, not fully open or fully closed, because the structural characteristics of the butterfly valve are not suitable for truncation, which will cause accelerated wear of the sealing surface.
5. Valves that have not been put into use for a long time should also be checked regularly to clean up dirt in time. Both ends of the butterfly valve channel should be closed to prevent long-term air oxidation. The product should be placed in a ventilated and dry place, not stacked or stored in the open air.
6. Eliminate the dirt on the valve parts before installation, carefully check the pressure of the valve mark to see if the diameter meets the requirements for use, and eliminate the defects caused by the transportation process.
7. The product switch must use the equipped hand wheel or electric or pneumatic device. Do not use external tools to cause damage to the valve. The handwheel butterfly valve is turned clockwise to close, otherwise it is open.
For stainless steel metal seated butterfly valves to be used for a long time, it is important from product selection to post-maintenance. Choosing a trustworthy brand is the first step, and maintenance is the continuation of quality. Of course, good manufacturers will also have more guarantees after sales. If users do not understand maintenance or have any questions or questions, they can directly contact the manufacturer for professional assistance. Tanghai Valve solemnly promises to pay two for each failure within two years. Is your trustworthy butterfly valve manufacturer.

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

Why is austenitic stainless steel magnetic

November 11, 2021

In the procurement case of austenitic stainless steel butterfly valves or gate valves, we can often find an interesting phenomenon. Customers carry magnets with them to check whether the material of the product is genuine. I think it is really “stainless steel” if it can’t be absorbed, and it’s faked with “stainless iron” if it sucks. This is really an “unjust case”. Today this article will share the unscientific aspects of this method.

high performance-double eccentric-butterlfy valve-wafer-lug-flanged (5)

The main reason for the emergence of the magnet inspection method is the recognition of a characteristic of austenitic stainless steel, that is, everyone must know that austenite is non-magnetic or weakly magnetic, while martensite or ferrite is magnetic. . Stainless steel is classified according to its organizational structure at room temperature: 1. Austenite type: such as 304, 321, 316, 310, etc.; 2． Martensite or ferrite type: such as 430, 420, 410, etc.; however, everyone ignores the change in ferrite content caused by the difference in forging and casting processes. This kind of magnetism, which is caused by chemical composition fluctuations or different processing conditions caused by smelting, cannot be regarded as counterfeit or substandard. Let’s see why?
1. During smelting, if composition segregation or improper heat treatment, a small amount of martensite or ferrite structure will appear in austenitic stainless steel. In this way, the austenitic stainless steel gate valve will have weak magnetism.
2. After austenitic stainless steel is cold-worked, the structure will also be transformed into magnetic martensite. The greater the degree of cold-working deformation, the more martensite transformation and the greater the magnetic properties of the steel.

marine valve; butterfly valve; check valve; gate valve; manufacturer in China

3. When polishing the product, use an iron wrist to polish it. If it is not cleaned or there are iron filings on the surface, it will show magnetism.
However, the magnetism of austenitic stainless steel caused by the above reasons is not at the same level as that of other stainless steels, such as 430 and carbon steel. That is to say, even if austenitic steel shows a certain degree of weak magnetism, it makes the magnet feel When it comes to suction, it is by no means strong magnetism, and the product itself is still qualified. In other words, if the austenitic stainless steel gate valve is weakly magnetic or non-magnetic at all, it should be judged as 304 or 316 austenitic stainless steel. If the magnetism is the same as that of carbon steel and shows strong magnetism, the product material is not austenitic steel but other materials are used indiscriminately.
If manufacturers want to completely eliminate the magnetic properties of austenitic stainless steel caused by the above reasons, they can restore and stabilize the austenitic structure through high-temperature solution treatment, thereby eliminating the magnetic properties. At the same time, select sand with high silicon content during forging and polishing treatment and then pickling passivation to remove magnetism. At the same time, as a user, when we are purchasing, we also recommend to choose products from reputable manufacturers, not to be greedy for cheap prices and avoid being deceived.

Therefore, it is unscientific to use a magnet to detect whether austenitic stainless steel contains magnetism.

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

Structure and applicable working conditions of electric butterfly valve

November 10, 2021

Electric butterfly valve is one of electric valve and electric regulating valve. There are mainly flange type electric butterfly valve and wafer type electric butterfly valve, which are classified according to the connection method of electric butterfly valve. The electric butterfly valve is usually composed of a quarter-stroke electric actuator and a butterfly valve through a mechanical connection, after installation and debugging.

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

According to the action mode, electric butterfly valves are classified into on-off type and regulating type. The switch type is to directly switch on the power supply to complete the switching action by switching the positive and negative directions. Regulating type uses AC220V power supply as power and receives 4-20mA signal preset by the industrial automation control system to complete the adjustment action. In various industrial automation production pipeline flow, pressure, temperature control, such as electric power, metallurgy, petrochemical, environmental protection, energy management, fire protection systems, etc., there are electric butterfly valves. Below we are going to take a look at the different working conditions applicable to different types of electric butterfly valves:
1. Wafer type electric butterfly valve, suitable for medium temperature ≤80～120℃, such as food, chemical, petroleum, electric power, textile, paper and other water supply and drainage, gas pipelines, used as flow adjustment and interception medium.
2. The soft-sealed electric butterfly valve has very good sealing performance. It can be made as a sanitary valve to achieve the effect of not polluting the medium.
3. The hard-sealed electric butterfly valve is made of hard alloy or stainless steel, which makes the sealing surface high in strength, hardness and wear resistance. Tanghai’s hard-sealed electric butterfly valve can be opened and closed continuously for more than 10,000 times without damage.
4. Flange electric butterfly valve, tightness, corrosion resistance, high temperature resistance and wear resistance have been firmly ensured, and it is suitable for high temperature and high pressure working conditions.
5. The rubber-lined electric butterfly valve is suitable for use in fresh water, sea water, salt, weak alkali, weak acid, natural gas, air, steam, oil, food and other media because of its good sealing performance.
6. The ventilation electric butterfly valve is made of the same material as the valve body and processed into a sealing ring. Its applicable temperature depends on the material selection of the valve body. The nominal pressure is ≤ 0.6MPa. It is usually used in industrial, metallurgical, environmental protection and other pipelines for ventilation and adjustment of medium flow.
There are still many uses for electric butterfly valves. For the selection of electric butterfly valves, you can also listen to the manufacturer’s suggestions. If you have the intention to purchase electric butterfly valves, you can contact us at any time. Tanghai will have professionals to give you reasonable suggestions according to your working conditions and assist you in purchasing practical electric butterfly valve products.

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

What kind of centerline wafer butterfly valve is a high-quality butterfly valve

November 5, 2021

There are many types of butterfly valves. Today we mainly want to discuss the centerline wafer butterfly valve, which is our more common type of butterfly valve. It has a wide range of applications, and currently there are many

Wafer type butterfly valve with worm gear

manufacturers of soft-seal wafer type butterfly valves. However, the quality and appearance of these butterfly valve products are still very different. How do we judge the quality of butterfly valves when we purchase butterfly valves? What are the characteristics and elements of a good centerline wafer butterfly valve? Tanghai Valve also summarized some of the feedback from many customers on-site and shared it with all users and friends.

1. Many of the centerline wafer butterfly valves are soft-sealed butterfly valves, lined with fluorine or rubber. Therefore, the quality of the material of the sealing pair requires high standards. Such as rubber, high-quality rubber can be long-lasting and elastic to play a good sealing role. However, the low-quality rubber hardened in a short time, and the valve naturally stuck or leaked internally. Therefore, in many cases, the final quality of the product is determined by details that are easily overlooked. For another example, the shaft hole on the valve stem and the valve body must have bushings, and the function of the bushing is to limit the bending deformation of the valve stem under pressure. The sealing ring between the valve stem and the valve stem shaft hole should be designed reasonably to ensure that the medium will not penetrate between the valve stem and the valve stem shaft hole. The bushing and sealing ring on the valve stem should not increase the torque too much.
2. Small torque, long service life, and good adjustment performance are all evaluation criteria.
3. Good airtightness and guaranteed leakage level!

To achieve good quality of the centerline wafer butterfly valve, butterfly valve manufacturers need to strictly control from several aspects. One is from the structure, such as bearings, valve stems, actuator connections, etc. are well-made. The design between the valve seat and the valve body can be more rationalized. Second, the processing technology is brave to innovate on the basis of maturity and adapt to more working conditions. Material selection should be scientifically optimized to ensure that the performance of the material meets the characteristics of the medium. In the selection, professional manufacturers should also provide customers with mature application experience to assist in purchasing. Actively collect feedback from users on product quality and respond to market demand in a timely manner.
The centerline wafer butterfly valve is very popular in the market, but any product has its own weaknesses. The weak point of the centerline pair clip-on butterfly valve is that when it is opened and closed, the unavoidable valve plate and valve wall are scratched and worn, which affects the service life. Therefore, Tanghai Valve is also actively launching a new double eccentric soft sealing butterfly valve. Due to the ingenious design of eccentricity, the valve plate can quickly leave the valve wall when it is opened, the sealing surface is protected, and the service life is longer. Coupled with a soft seal, the sealing performance is better. Tanghai’s double eccentric soft-seal butterfly valve also received very good market response soon after its launch. You are welcome to inquire.

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

Comparison of the characteristics of wafer butterfly valves and flanged butterfly valves

November 4, 2021

To find out what is the difference between the wafer butterfly valve and the flange butterfly valve, let’s take a look at the comparison of some characteristics of the wafer butterfly valve and the flange butterfly valve.

Wafer type butterfly valve with worm gear

The biggest difference is of course that the flanged butterfly valve has two more flanges, and the wafer type has two fewer flanges. Of course, the price is cheaper, and the price is about 2/3 of the flange. Flange butterfly valves are more reliable than wafer butterfly valves. Wafer butterfly valves are not as convenient as flanged butterfly valves in installation, because they need to be equipped with flanges, which can easily leak if they are not installed well.

From the perspective of specific working conditions, when selecting imported valves, use wafer-type butterfly valves as much as possible, which are light in weight and easy to replace. However, the length of the bolts of the wafer butterfly valve is longer, and the construction accuracy is higher. If the flanges on both sides are not aligned, the bolts will be subjected to greater pressure and the valve is prone to leakage. Under high temperature conditions, the bolts of the wafer butterfly valve may cause leakage after expansion, so if it is under high temperature conditions, the wafer butterfly valve is not suitable for large pipe diameters. In addition, wafer butterfly valves generally cannot be used at the end of the pipeline and downstream where it needs to be disassembled, because when the downstream flange is disassembled, the wafer valve will fall off. In this case, a short section must be made separately. For disassembly. The wafer butterfly valve has no flanges at both ends of the valve body, only a few guide bolt holes, and the valve is

Double flange butterfly valve (17)

connected with the flanges at both ends by a set of bolts/nuts. Compared with flanged butterfly valves, it is easier to disassemble. The cost of the valve is lower, but the disadvantage is that one sealing surface has a problem, and both sealing surfaces have to be disassembled. Regarding the blue butterfly valve, the above problem does not exist, and of course it has to pay a higher cost. But the cost will be higher.

The flange type butterfly valve has flanges at both ends of the valve body, which are connected with pipe flanges. The seal is relatively more reliable.
In addition to selecting the appropriate wafer butterfly valve or flange butterfly valve, attention should also be paid to the installation and maintenance of the butterfly valve. Because this is actually a place that can affect the selection of the valve outside of the specific purpose. Let’s take a look at the specific requirements below:
1. The valve disc stops at the closed position during installation.
2. Determine the opening position according to the rotation angle of the butterfly plate.
3. For the butterfly valve with bypass valve, the bypass valve should be opened before opening.
4. Ask professionals to install according to the manufacturer’s instructions, especially the heavy butterfly valve should be fixed.
5. 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 rotated to 90°, the butterfly valve is fully open.
The butterfly valve is used as a flow control, the main thing is to choose the size and type of the valve when purchasing. 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.

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

Operation precautions of stainless steel butterfly valve

November 2, 2021

Stainless steel butterfly valves are usually metal seated butterfly valves, which can be driven by manual, pneumatic, etc., and are suitable for use in high temperature and corrosive medium pipelines. Stainless steel butterfly valves are currently widely used in the market and can be seen in many fields. Especially in metallurgy, chemical industry,

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

building materials, power stations, glass and other industries in the dusty cold or hot air pipelines of ventilation and environmental protection projects, it plays an important role as a gas medium to adjust the flow or cut off the device.

Stainless steel butterfly valves mainly have the following two characteristics:
1. It is designed and manufactured with a new structure welded by a centerline disc plate and a short structure steel plate. It is compact in structure, light in weight, easy to install, small in flow resistance, large in circulation, avoiding the influence of high temperature expansion, and easy to operate.
2. There are no connecting rods, bolts, etc., so it works reliably and has a long service life. It can be installed in multiple positions and is not affected by the flow direction of the medium.
The advantages and disadvantages of stainless steel butterfly valves are: advantages. 1. It is convenient and quick to open and close, labor-saving, low fluid resistance, and can be operated frequently. 2. Simple structure, small size and light weight. 3. Mud can be transported, and the accumulation of liquid at the pipe mouth is the least. 4. Under low pressure, good sealing can be achieved. 5. Good adjustment performance. shortcoming. 1. The working pressure and working temperature range are small. 2. Poor airtightness.
In view of these characteristics, we first strictly follow the operating procedures in the instructions in our usual operations. Finally, pay attention to observe the valve opening and closing instructions and the operation of the valve stem, and the valve opening and closing degree must meet the requirements. In the process of opening and closing the valve, if the signal indicator is found to be wrong or the valve makes an abnormal sound, it should be shut down in time for inspection. We pay attention to these problems in daily use, so as to reduce the damage caused by operating errors in stainless steel butterfly valves.
Stainless steel butterfly valve is one of the valve products that many manufacturers need to purchase. Customers must pay attention to the selection of valve manufacturers when choosing specific valve parameters such as model size and caliber. Only by choosing a reputable and advantageous valve manufacturer can the valve quality be better and the later repairs more convenient.

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

Application of metal seated butterfly valve in metallurgical field

October 28, 2021

In the initial use of metallurgical blast furnaces, gate valves occupies half of the country. However, as the government has increased its efforts in environmental protection construction, and the pipe diameter of the blast

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

furnace system has gradually increased, the metal seated butterfly valve, which is light in weight, good in sealing performance, small in torque, and more suitable for making large-diameter valves, has gradually replaced gate valves. It is widely used in the field of metallurgy.
The metal hard seal butterfly valve has two driving methods: hydraulic drive and electric drive. In the ironmaking blast furnace, it is mainly installed in the waste heat utilization system, the dry dust removal system and the gas pipe network. It is used under the high temperature conditions of large nominal diameter, low working pressure and opening and closing pressure difference, and temperature of 200-350℃ . Because most of the metallurgical system pipelines are high-temperature gas media, the metal hard seal eccentric butterfly valve has been developed.
The metal hard sealing butterfly valve adopts surface-to-surface contact, and the sealing material is metal, so it is more resistant to high temperatures, even up to 400°C. However, correspondingly, the selection of metal seals has become very important. We must choose old brands and professional brands. Because brand manufacturers pay attention to reputation and their qualifications are relatively sound, we can check whether the metal seal is of high quality when purchasing, which can ensure that it maintains flexibility under high temperature conditions. This is also the possibility to ensure that the metal eccentric butterfly valve will not deform and leak after a period of use.
Now Tanghai also has a triple-eccentric butterfly valve whose sealing pair is a multi-layer composite material, which is a composite of metal and non-metal materials. This further makes up for the slight inferiority of metal sealing performance to fluorine lining, especially the non-metal interlayer in the middle can make the sealing of the sealing pair produce a stepped sealing form. After long-term use, it can still maintain good and reliable high-temperature use effects. The disadvantage is that the valve can maintain good sealing performance while maintaining high temperature and aging resistance. Various systems in metallurgical blast furnaces have been widely used, especially high-temperature systems.
Metal hard seal butterfly valves are suitable for high temperature gas pipeline systems in metallurgy, mining, cement, chemical, power generation and urban heating industries, as opening and closing equipment. In addition, Tanghai’s metal eccentric hard seal butterfly valve has compact structure, few parts, small size, light weight, high temperature resistance, flexible opening and closing, and can achieve zero leakage under long-term working conditions, long service life, and low power required. , The future will also usher in a wider range of applications.

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

How to choose concentric |double eccentric |triple eccentric butterfly valve

October 26, 2021

The difference in butterfly valve structure distinguishes four types of butterfly valves, namely: concentric butterfly valve, single eccentric butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve. What is the concept of this eccentricity? How to decide when to use concentric butterfly valve, when to use single eccentric

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

butterfly valve, when to use double eccentric butterfly valve and triple eccentric butterfly valve? Many users are not particularly clear. We might as well share together.
Concentric butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves and triple eccentric butterfly valves reflect the process of opening and closing more and more labor-saving, and the sealing surface wear is getting smaller and smaller. By setting the position of the shaft of the butterfly valve valve plate, the sealing and opening state of the butterfly valve can be changed. Under the same conditions, the torque of the valve is greater than one at each opening. When the valve is opened, the angle required for the valve plate to be separated from the seal is smaller than one.
The structural feature of the concentric butterfly valve is that the shaft center of the valve stem, the center of the butterfly plate, and the center of the valve body are in the same position. Generally, if you can use concentric butterfly valves in principle, use concentric butterfly valves as much as possible. Because the concentric butterfly valve does not require high sealing performance in terms of structure or operation, it is a conventional product. In order to overcome squeezing, scratching, and to ensure the sealing performance, the seat of the concentric butterfly valve is basically made of rubber or polytetrafluoroethylene and other elastic materials,

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

which is a soft sealing butterfly valve. This makes the concentric butterfly valve subject to temperature restrictions in use. In order to solve the problem of the squeezing of the butterfly plate and the valve seat of the concentric butterfly valve, a single eccentric butterfly valve was also produced. Its structural feature is that the shaft center of the valve stem deviates from the center of the butterfly plate.
Double eccentric butterfly valve is the most widely used. Its structural feature is that the shaft center of the valve stem deviates from the center of the butterfly plate and the center of the valve body. It deviates from the two center positions so it is called a double eccentric butterfly valve. Many double eccentric butterfly valves are line-sealed. When the sealing surface is closed, friction occurs between the disc and the valve seat, and the sealing effect is very good. It has the characteristics of small area and strong pressure. After the valve is opened, the butterfly plate can be quickly separated from the valve seat, which greatly eliminates unnecessary excessive squeezing and scratching of the butterfly plate and the valve seat, reduces the opening resistance, reduces the wear, and improves the life of the valve seat.
The triple eccentric butterfly valve is eccentric for the third time on the basis of the double eccentric butterfly valve. The shape of the sealing pair is not a positive cone, but an oblique cone. Mostly short-distance force and face seal. The stem shaft of the triple eccentric butterfly valve is a three-section shaft structure. The two shaft sections of this three-section shaft valve stem are concentric, and the center line of the central section shaft deviates from the axis of both ends by a center distance, and the butterfly plate is installed in the middle On the shaft section. Such an

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

eccentric structure makes the butterfly plate a double eccentric shape when in the fully open position, and a single eccentric shape when the butterfly plate rotates to the closed position. Due to the effect of the eccentric shaft, when it is close to closing, the butterfly plate moves a distance into the sealing cone surface of the valve seat, and the butterfly plate matches the sealing surface of the valve seat to achieve reliable sealing performance. It makes up for the contradiction that the hard seal has poor sealing, and the soft seal has good sealing effect but is not resistant to high temperatures. When to use a concentric butterfly valve and when to choose a double eccentric butterfly valve or a triple eccentric butterfly valve, it mainly depends on the usage habits and budget. If it is not for extreme working conditions, concentric butterfly valves can generally be selected, and concentric butterfly valves should be used as much as possible. Because the concentric butterfly valve is simple in structure and relatively economical in price.

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

Resilient seated /soft-seal butterfly valve prices

October 22, 2021

The purchase price of soft-sealed butterfly valves is a problem that many customers are concerned about when inquiring, but because the valve is not like furniture and other items in the structure and material is relatively

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

simple, there are more components of the valve, and according to the material used in different working conditions, The components are different, which makes it difficult to give a fixed quotation for the soft-sealed butterfly valve, which should be based on the actual situation. How much it costs to purchase a soft sealing butterfly valve has a lot to do with the material of the valve plate, the material of the valve body, the material of the sealing ring, manual or automatic, etc. Let’s take a look at the specific factors that affect the purchase price of soft-sealed butterfly valves?
1. Material of valve plate. The material of the valve plate of the soft sealing butterfly valve is nylon plate, galvanized plate, 304 plate, 316 plate, etc. The selection of the valve plate is determined according to the medium to be taken by the customer’s pipeline. The general medium mainly relates to whether it is corrosive. If it is not corrosive, you can choose galvanized sheet, and if it is corrosive, you can choose stainless steel 304 plate or 316 plate. Cold-rolled stainless steel costs more than 10,000 yuan per ton, while galvanized steel is several thousand yuan per ton, so obviously the price will be different for different materials.
2. Material of sealing ring. The sealing ring of soft sealing butterfly valve is generally rubber or fluoroplastic. The rubber sealing ring includes nitrile rubber, EPDM rubber, and tetrafluoro rubber. Several rubbers have their own advantages. Nitrile rubber is oil-resistant, and EPDM rubber is resistant to aging. PTFE rubber is resistant to weak corrosion. The temperature resistance of nitrile rubber and EPDM rubber is about 80 degrees, and the temperature resistance of tetrafluoro rubber is about 150 degrees. So we still have to choose according to the temperature and characteristics of the medium. If the temperature is around 80 degrees, you can choose nitrile rubber or EPDM rubber. If the temperature exceeds 80 degrees, you can choose tetrafluoro rubber. Fluoroplastics can also be used when the medium is corrosive but not high temperature. The price of fluoroplastics will be much more economical than rubber.
3. Manual or automatic. The soft sealing butterfly valve is divided into manual and automatic. Manual is the handle butterfly valve, turbine butterfly valve, the driving method is mainly manual. However, electric butterfly valves and pneumatic butterfly valves do not need to be operated manually but are opened and closed automatically by the device. Of course, the price is relatively higher than that of manual ones.
In addition to the above, the size of the valve’s caliber, the size of the applicable pressure, whether it is a flange connection or a wafer connection or an electric welding connection, these factors will all affect the purchase price of the soft sealing butterfly valve. So if you want to know the purchase price of the soft sealing butterfly valve you need, the easiest and best way is to quickly contact our Tanghai staff to give you a professional quotation. According to the working conditions, pressure and medium conditions you provide, Tanghai Professional Services will recommend the most suitable valve types for you and quickly give you an accurate quotation. You are welcome to inquire!

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

factors affecting the sealing performance of resilient butterfly valve seat

October 21, 2021

Rubber butterfly valve is an important part of regulating flow medium, and tight sealing is the most important quality of the product. The sealing performance of rubber butterfly valves is affected by many factors, and the most important influence is still closely related to the sealing surface. Today we will focus on three factors. Let’s take a

Wafer type butterfly valve with worm gear

look at the main factors that affect the sealing performance of rubber butterfly valves:

1. Quality of the sealing surface/valve seat
First of all, we must make it clear that the sealing surface refers to the part where the valve seat and the disc are in contact with each other for medium opening and closing control, and only which part of the valve seat and the disc are in contact instead of the entire sealing pair. The quality of the sealing surface is mainly related to the quality of the sealing material. The quality of the sealing material should be produced by the brand manufacturer and qualified in process. In addition, the choice of sealing material should be in line with the medium. For example, rubber butterfly valves cannot be used for highly corrosive media.

2. Width of sealing surface/valve seat
The width of the sealing surface mainly affects the movement resistance of the fluid. The larger the sealing surface, the lower the resistance, and the narrower the resistance is relatively large. Therefore, the increase in the width of the sealing surface can reduce the erosion and wear of the sealing surface by the fluid. At the same time, because the increase in the width of the sealing surface increases the length of the leakage stroke proportionally, the leakage can be reduced proportionally. However, the width of the sealing surface must not be excessively increased, because an increase in the width of the sealing surface, under the same sealing force, the reduction of the specific pressure of the seal will increase the possibility of leakage.

3. The pressure difference between before and after the valve
The specific pressure on the sealing surface is caused by the pressure difference between the front and rear of the valve and the applied sealing force, which refers to the pressure acting on a unit area of the sealing surface. The specific pressure directly affects the sealing performance, reliability and service life of the rubber butterfly valve. When the specific pressure on the sealing surface is small and the surface roughness is low, the leakage increases rapidly. When the specific pressure on the sealing surface is large, the effect of surface roughness on the leakage is significantly reduced.

In addition, the sealing performance of the rubber butterfly valve is related to the sealing surface material of the butterfly valve and its processing state, the nature of the medium, the existence of the sealing oil film, the rigidity and structural characteristics of the closing part, and so on. For more information, please call Tanghai for inquiries, and we will have professionals to answer your questions about 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

Posts

How to extend the service life of stainless steel metal seated butterfly valve

Why is austenitic stainless steel magnetic

Structure and applicable working conditions of electric butterfly valve

What kind of centerline wafer butterfly valve is a high-quality butterfly valve

Comparison of the characteristics of wafer butterfly valves and flanged butterfly valves

Operation precautions of stainless steel butterfly valve

Application of metal seated butterfly valve in metallurgical field

How to choose concentric |double eccentric |triple eccentric butterfly valve

Resilient seated /soft-seal butterfly valve prices

factors affecting the sealing performance of resilient butterfly valve seat

TH VALVE • PROFESSIONAL VALVE MANUFACTURER

GET IN TOUCH WITH US