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Precautions for the use of triple eccentric metal seated butterfly valve

Triple eccentric hard-sealed butterfly valves are generally metal seated butterfly valves, which have an eccentric metal sealing structure. Sealing forms include metal-to-metal sealing, stainless steel plate and graphite composite plate sealing ring to metal sealing, etc. The driving methods are mainly electric, manual, turbo rod transmission,

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

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

pneumatic and so on. The triple eccentric hard-seal butterfly valve is very popular in the market. It maintains the advantages of the centerline butterfly valve and discards the disadvantage of the poor sealing performance of the metal seal. It is a more promising product in the market. Let’s take a look at the problems we need to pay attention to in use:
1. The triple eccentric hard sealing butterfly valve is a multi-layer soft and hard stacked sealing ring, which is also a very significant feature of the triple eccentric hard sealing butterfly valve. The seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of the soft T-shaped sealing ring. When the valve plate is in the normally open state, the medium will form a positive scouring on its sealing surface, and the soft sealing tape in the metal sheet sandwich will directly affect the sealing performance after being scoured.
2. The valve will be restricted by the structural conditions, so the structure is not suitable for valves with a diameter below DN200, because the overall structure of the valve plate will be too thick and the flow resistance will be large.
3. The principle of the valve’s triple eccentric structure. The sealing between the sealing surface of the valve plate and the valve seat is to press the valve plate against the valve seat by the torque of the transmission device. It is a self-sealing property. That is, when the medium is flowing in the forward direction, the higher the medium pressure, the tighter the sealing and squeezing. However, in general, when the flow channel medium flows back, as the medium pressure increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the seal will begin to leak.
Is there a solution to the inability to achieve two-way sealing? Butterfly valve manufacturers add an adjustment ring between the pressure plate and the valve seat to achieve a very ideal two-way hard seal. The sealing surface of the valve plate and the valve seat of the triple eccentric sealing butterfly valve is an oblique cone structure, and temperature-resistant and corrosion-resistant alloy materials are surfacing welded on the oblique cone surface of the valve plate. A structure in which the spring fixed between the pressure plate of the adjusting ring and the adjusting bolt of the pressure plate are assembled together. This structure effectively compensates for the tolerance zone between the shaft sleeve and the valve body and the elastic deformation of the valve stem under the medium pressure, and solves the sealing problem of the valve in the two-way interchangeable medium conveying process.
When the medium flows backward, the seal between the valve plate and the valve seat depends on the torque of the driving device to press the valve plate against the valve seat. With the increase of the reverse medium pressure, when the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the deformation energy stored by the spring of the adjusting ring after being loaded compensates for the tight pressure of the sealing surface of the valve plate and the valve seat Play the role of automatic compensation.
The triple eccentric hard seal butterfly valve adopts a soft T-shaped multi-layer stainless steel sheet on both sides to form a sealing ring. It has the dual advantages of metal hard and soft sealing, and has zero leakage sealing performance regardless of low temperature and high temperature. In the future, it may also replace gate valves and ball valves.

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

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

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

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 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

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Advantages of Triple Eccentric Metal seated Butterfly Valve

The triple eccentric butterfly valve belongs to the metal seated butterfly valve. The triple eccentricity is named because its stem axis deviates from the center of the disc and the center of the body at the same time, and there is a certain angle between the axis of rotation of the valve seat and the axis of the valve body channel. The triple-eccentric butterfly valve is corrosion-resistant, wear-resistant, and has a long service life. It is suitable for working conditions

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

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

where the medium temperature is ≤425℃. It is widely used in metallurgy, electric power, petrochemical, and water supply and drainage, municipal construction and other industrial pipelines for adjustment. Flow rate and use of off-load fluid. The body materials of the triple eccentric butterfly valve are cast iron, cast steel and stainless steel. This article will make an analysis and introduction to the advantages of the triple eccentric butterfly valve.

1. The metal-to-metal elastic hard seal structure is a structure in which an elastic metal J-ring is installed on the valve seat. The J-ring is pressed by a pressure plate and fixed with bolts. The two sides of the J-ring are respectively provided with sealing rings with good sealing performance, high temperature and high pressure resistance, and a certain margin. The position of the J-ring can be adjusted to make the valve After a period of use, it will not leak due to wear. The valve is suitable for medium and high temperature and medium and high pressure pipeline systems.

2. High wear-resistant self-lubricating composite bearings are used in the key parts of the relative movement of the shaft and the body to reduce the friction of the butterfly plate when it is opened or closed, and to ensure that there is no wear between the shaft and the body.

3. At the bottom of the lower shaft of the valve body, a high-hardness wear-resistant alloy spherical thrust pad and a high-hardness flat pad are used. During the movement of the butterfly plate, all downward gravity and friction forces are concentrated here. Due to the high hardness of the two thrust pads, the small contact area, long-term movement without abrasion, to ensure that the valve opens and closes easily, and never sinks.

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

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

4. The triple eccentric structure is a qualitative leap of the butterfly valve. Therefore, the valve greatly improves the service life and significantly improves the opening and closing torque. If you don’t understand the triple eccentric structure, you can click (https://www.tanghaivalve.com/triple-eccentric-butterfly-valve-th-btv-te/) to view.

5. The metal-to-metal multi-layer composite hard seal structure is a structure in which a multi-layer composite metal ring is installed on the valve plate. The multi-layer composite metal ring is made of stainless steel metal plates and flexible graphite sheets repeatedly laminated and pressed, which has high strength and rigidity. Flexible graphite still has good sealing performance under high temperature and high pressure. The combination of rigidity and flexibility of these two materials makes the valve suitable for most media, with a wide range of applications and long service life.

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

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What are the characteristics of the hard seal butterfly valve

Hard seal butterfly valve is a kind of butterfly valve with eccentric metal seal structure, and it is usually required to be installed horizontally in the pipeline. The sealing form of the metal hard seal butterfly valve is usually a metal-to-metal seal, and the sealing pair is composed of a metal hard material to a metal hard material. Hard-sealed butterfly valves can be driven by turbine manual, electric, pneumatic and so on.

triple offset butterfly valve-double flange- (5)

triple offset butterfly valve-double flange- (5)

Nowadays, hard-sealed butterfly valves have been widely used in many fields such as petroleum, chemical industry, metallurgy, power generation, etc., to cut off or control the circulating medium in the pipeline system. At this stage, there is a relatively advanced hard-sealed butterfly valve, which is a triple-eccentric metal seated butterfly valve. Its body and seat are a conjoined component. On the sealing surface layer of the valve seat, a temperature-resistant and corrosion-resistant alloy material is surfacing welded. , And fix the multi-layer soft stacked sealing ring on the valve plate. The novel design allows the triple eccentric butterfly valve to overcome the shortcomings of poor sealing performance. The advantages of the triple eccentric butterfly valve are high temperature resistance, low friction when opening and closing, and when closed, the butterfly plate compensates for the seal along with the increase of the torque of the transmission mechanism, which greatly improves the sealing performance of the hard seal butterfly valve and prolongs the service life of the valve.

The advantages of the triple eccentric hard seal butterfly valve are:
1. The unique three-eccentric design enables frictionless transmission between the butterfly plate and the sealing surface of the valve body, reducing wear and extending the service life.
2. It can adapt well to low temperature, normal temperature and high temperature environment.
3. Pneumatic and electric devices can be configured according to the needs of users to meet the needs of remote control and program control.

The shortcomings of the triple eccentric hard seal butterfly valve are:
1. The butterfly plate of the hard sealing butterfly valve is fixed by multiple layers of soft and hard stacked sealing rings. When the butterfly plate is in the normally open state, the flowing medium will flush the sealing surface positively, which will affect the sealing performance of the valve over time.
2. Because the overall structure of the hard-sealed butterfly valve’s butterfly plate is too thick and the flow resistance is relatively large, the valve is not suitable for diameters below DN200.

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

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Features of Stainless Steel Valves

Generally speaking, stainless steel valves are valves made of stainless steel. They are classified according to the stainless steel material grade of the valve body. They are mainly 301, 304, 316, 304L, 316L, etc. According to international standards, they can be divided into CF8, CF3, CF8M, CF3M, the quality of the material

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

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

CF8<CF3<CF8M<CF3M. Because stainless steel has strong corrosion resistance, is easy to form, has high compatibility, and can remain strong in a wide temperature range, many advantages make stainless steel valves widely used in heavy industry, light industry, daily necessities industry and architectural decoration industry. middle.
Stainless steel refers to steel that is resistant to corrosion by weak corrosive media such as air, steam, water and chemical corrosive media such as acids, alkalis, and salts. It is also called stainless acid-resistant steel. Stainless steel valves are also stainless acid-resistant steel valves. , And resistant to acid and alkali corrosion. Research tests have shown that the corrosion resistance of steel in weak media such as the atmosphere and water and oxidizing media such as nitric acid will increase with the increase of the chromium water content in the steel. When the chromium content reaches a certain percentage, the corrosion resistance of steel The sex changes, that is, from easy to rust to not easy to rust, from no corrosion resistance to corrosion resistance.
Common stainless steel valves mainly include stainless steel butterfly valves and stainless steel ball valves. The gate valve is rarely made of stainless steel, because the gate valve is usually used for low corrosive media such as water.
Stainless steel butterfly valve, also known as stainless steel flap valve, usually adopts three-eccentric metal hard sealing structure. The valve body, valve seat and butterfly plate sealing surface are all made of stainless steel with different hardness, which has strong corrosion resistance and long service life. It is widely used in metallurgical, electric power, petrochemical, water supply and drainage, municipal construction and other industrial pipelines with fluid pipeline medium temperature ≤ 425°C.
Stainless steel ball valves usually require horizontal installation in the pipeline. Stainless steel ball valves can be divided into stainless steel pneumatic ball valves, stainless steel electric ball valves, and stainless steel manual ball valves according to the driving mode. According to different stainless steel materials, it is divided into 304, 316, 321 stainless steel ball valves. The stainless steel ball valve switch is light and can also be made into a large diameter. It has reliable sealing, simple structure and convenient maintenance. The sealing surface and spherical surface are often in a closed state and are not easily eroded by the medium. It has applications in various industries.

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

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Problems Existing in the Use of Triple Eccentric Butterfly Valves

The triple eccentric metal seated butterfly valve is a high-quality valve category with high reliability and a wide range of applications. The triple eccentric butterfly valve is composed of main components such as valve body, butterfly

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

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

plate, valve stem, multi-layer metal sealing ring, shaft seal and drive mechanism. Its advantages are solid structure, good sealing performance, small torque, easy automatic control, etc. The triple eccentric butterfly valve is suitable for a variety of demanding working conditions, and has a wide range of applications in petroleum refining, natural gas extraction, chemical industry, power stations, metallurgy, and urban heating. However, things have two sides, and there are many problems in the use of the three-eccentric metal seated butterfly valve.
1. The butterfly plate of the triple eccentric butterfly valve is fixed with multiple layers of soft and hard stacked sealing rings. When the butterfly plate is in the open state, the circulating medium will directly wash the sealing surface. The soft sealing material in the metal sheet sandwich is in the long-term wash of the medium. It will directly affect the sealing performance of the valve.
2. The triple eccentric butterfly valve is not suitable for valves with a diameter smaller than DN200 because of its own structural constraints, the entire butterfly plate is very heavy and the flow resistance is very large.
3. The sealing between the butterfly plate sealing surface and the valve seat of the triple eccentric butterfly valve is to press the butterfly plate against the valve seat by the torque of the transmission device. When the medium in the pipeline is in a state of positive flow, the higher the pressure of the medium, the tighter the sealing and squeezing. But when the medium in the pipeline flows back, the pressure of the medium may cause seal leakage.
In order to solve the problems existing in the use of the triple eccentric butterfly valve, a high-performance triple eccentric two-way metal seated butterfly valve was developed. For the two-way sealing triple eccentric butterfly valve, the seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of the soft T-shaped sealing ring. The sealing surface of the butterfly plate and the valve seat is an oblique cone structure, and then a high temperature and corrosion resistant alloy material is surfacing on the sealing surface of the oblique cone structure, and the spring fixed between the pressure plate of the adjusting ring and the adjusting bolt of the pressure plate are assembled together .
This special structure effectively compensates for the elastic deformation between the shaft sleeve of the triple eccentric butterfly valve and the valve body, and perfectly solves the problem that the triple eccentric butterfly valve is prone to leakage during the two-way interchangeable medium delivery process. The soft T-shaped sealing ring composed of multilayer stainless steel sheets on both sides not only has the advantages of a metal seated material, but also has the characteristics of a soft sealing material. Therefore, the three-eccentric butterfly valve with two-way sealing is suitable for both low temperature and high temperature conditions. Under the conditions, it can maintain excellent sealing performance.

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

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Selection and application of eccentric butterfly valve
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