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What is a wafer type butterfly valve

The butterfly valve plate of the wafer type butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body,

Wafer type butterfly valve with worm gear

Wafer type butterfly valve with worm gear

the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0°-90°. When the rotation reaches 90°, the valve is fully opened. This valve is generally installed horizontally. 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 wafer type butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has better flow control characteristics. The butterfly valve has two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate.

Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the defect of being limited by temperature.

If the wafer type 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. 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.

Commonly used butterfly valves include wafer butterfly valves and flanged butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipe flanges. Flange type butterfly valve has flanges on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flanges.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves. The Key products: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

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

Related news /knowledge: Comparison and analysis of the performance of the wafer butterfly valve; Wafer butterfly valve installation instructions and steps; The structural characteristics and uses of the wafer butterfly valve;

Notes on selection and installation of butterfly valve

Product selection points of butterfly valves:
1. The main control parameter of the butterfly valve is the size.
2. The butterfly valve is a single-plate air valve. It has a simple structure, convenient processing, low cost, and easy operation, but the adjustment accuracy is poor. It

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

is only suitable for the occasion of switching or rough adjustment in the ventilation and air conditioning system.
3. It can be operated manually, electrically or by zipper, and can be fixed at any angle in the range of 90°.
4. Due to the single shaft and single valve plate, the bearing capacity is limited, and the service life of the valve is short under the condition of large pressure difference and large flow rate. The valve is divided into closed type and ordinary type, thermal insulation and non-thermal insulation.
5. The electric butterfly valve has only two-position control, and the electric actuator is the same as the multi-leaf valve.

Installation matters of butterfly valve:
The butterfly valve has a simple structure, small volume, light weight, and relatively few components. The key parts can form a butterfly valve. It is also very convenient to open. You only need to select the switch to ninety degrees. The butterfly valve The fluid control is very good, you can increase or decrease the flow at any time, the valve has a certain resistance when transporting any fluid, and the resistance of the butterfly valve mainly comes from its own, such as the thickness of the butterfly valve body, if you want to reduce the fluid The resistance only needs to reduce its thickness.
Elastic seals have the disadvantage of being limited by temperature.
Butterfly valves are also widely used. If they are used to control the flow rate, different types and sizes of valve bodies need to be selected, because butterfly valves are more suitable for valves with larger diameters when they are designed. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, and water treatment, but also in cooling water systems of thermal power stations.

Tianjin Tanghai dongyang valve Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves. Product ranges: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

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

Related news /knowledge: Selection and application of eccentric butterfly valve; What is the material of the main parts of the butterfly valve?-(2); 

Common failures of butterfly valves and the characteristics of installation

Common errors of butterfly valves:
The rubber elastomer in the butterfly valve will tear, wear, aging, perforate or even fall off during continuous use. The traditional thermal vulcanization process is

Double flange butterfly valve (16)

Double flange butterfly valve (16)

difficult to meet the needs of on-site repair. Special equipment is used for repair, which consumes a lot of heat and electricity, which takes time and effort. Today, we use new method gradually of adopting polymer composite materials to replace traditional methods. The superior adhesion and excellent wear and tear resistance of its products ensure that the repair cycle reaches or even exceeds the life cycle of new parts, greatly reducing downtime.

Installation and maintenance of butterfly valves:
1. During installation, the valve disc should stop at the closed position.
2. The opening position should be determined according to the rotation angle of the butterfly valve disc.
3. Butterfly valves with bypass valves should be opened before opening.
4. The installation should be carried out according to the manufacturer’s installation instructions. The heavy butterfly valve should be installed with a solid foundation.

Construction and installation points
1. The installation position, height, and direction of entrance and exit must meet the design requirements, and the connection should be firm and tight. The handles of all kinds of manual valves installed on thermal insulation pipes must not be downward.
2. The valve must be visually inspected before installation, and the nameplate of the valve should comply with the customer’s national standards. For valves with a working pressure greater than 1.0 MPa and acting as a shut-off on the main pipe, strength and tightness performance tests should be carried out before installation, and qualified before use. During the strength test, the test pressure is 1.5 times the nominal pressure, the duration is not less than 5min, and the valve housing and packing should be leak-free. During the tightness test, the test pressure is 1.1 times the nominal pressure; the test pressure lasts no less than 120 seconds during the test, and the valve flap sealing surface is qualified as no leakage.

Tianjin Tanghaidongyang valve Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves. Products range: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

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

related news /knowledge:
What is butt welding? (6)- Flash butt welding of common metals;
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What is assembly error and how to control it?;
What is machining accuracy, machining error, tolerance?;

Applicable occasions of butterfly valve

Butterfly valves are suitable for flow regulation. Because the pressure loss of the butterfly valve in the pipeline is relatively large, the robustness of the butterfly plate to withstand the pressure of the pipeline medium when closing should also be considered. In addition, the working temperature limit of the elastic seat material

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

must be considered at high temperatures. The structure length and overall height of the butterfly valve are small, the opening and closing speed is fast, and it has good fluid control characteristics. The structure principle of the butterfly valve is most suitable for making large-diameter valves. When the butterfly valve is required for flow control, the most important thing is to correctly select the size and type of the butterfly valve so that it can work properly and effectively.

Generally, in throttling, adjustment control and mud medium, the structure length is required to be short, and the opening and closing speed is fast (1/4 turn). Low pressure cut-off (small differential pressure), butterfly valve is recommended.

Butterfly valve can be used when there are two-position adjustment, narrowing channel, low noise, cavitation and gasification, small leakage into the atmosphere, and abrasive media.

Throttle adjustment under special working conditions, or strict sealing requirements, or severe wear, low temperature (cryogenic) and other working conditions when using butterfly valves, need to use special design metal seal triple-eccentric or double eccentric Butterfly valve with adjustment device.

5 double-eccentric-butterfly-valve-2

5 double-eccentric-butterfly-valve-2

The butterfly valve is suitable for requirements to achieve complete sealing, zero gas test leakage, high life requirements, and operating temperature between -10 degrees and 150 degrees. Applicable medium is fresh water, sewage, sea water, salt water, steam, natural gas, food, medicine, oil products And various acids and bases.

The soft seal eccentric butterfly valve is suitable for bidirectional opening and closing and adjustment of the ventilation and dust removal pipeline, and is widely used in gas pipelines and water channels in metallurgy, light industry, electric power, and petrochemical systems.

The metal-to-metal line sealed double eccentric butterfly valve is suitable for gas, oil, acid and alkali pipelines such as urban heating, gas supply, water supply, etc., as a regulating and throttling device.

In addition to being used as a large-scale pressure swing adsorption (PSA) gas separation device program control valve, the metal-to-metal face sealed triple-eccentric butterfly valve can also be widely used in the fields of petroleum, petrochemical, chemical, metallurgy, electric power, etc. as replacement product.

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

Related news /knowledge:
Description of lining material for rubber lining valve;
Notes on selection and installation of butterfly valve; 
Applicable occasions and operation method of ball valve;

How to choose the right butterfly valve (2)

However, the following problems still exist during the use of this butterfly valve:
1. Due to the multi-layer soft and hard laminated seal ring fixed on the valve plate, when the valve plate is normally open, the medium forms a frontal flush on the sealing surface. The soft sealing tape in the metal sheet interlayer is directly affected by the flushing, which directly affects the sealing performance.

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

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

2. Restricted by structural conditions, the structure is not suitable for valves with a diameter of DN200 or less, because the overall structure of the valve plate is too thick and the flow resistance is large.
3. Due to the principle of the three-eccentric structure, the sealing between the sealing surface of the valve plate and the valve seat is caused by the torque of the transmission device to press the valve plate against the valve seat. In the positive flow state, the higher the medium pressure, the tighter the seal extrusion. When the medium in the flow channel reverses flow, as the medium pressure increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, and the seal begins to leak.

The high-performance triple-eccentric bidirectional hard seal butterfly valve is characterized in that the valve seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of a soft T-shaped sealing ring. The sealing surface of the valve plate and the valve seat is an oblique cone structure. The surface of the oblique cone of the valve plate is welded with a temperature-resistant and corrosion-resistant alloy material; the spring fixed between the pressure plate of the adjustment ring and the adjustment bolt of the pressure plate are assembled together.
This structure effectively compensates the tolerance zone between the shaft sleeve and the valve body and the elastic deformation of the valve stem under medium pressure, and solves the sealing problem of the valve in the process of bidirectional interchangeable medium transportation. The use of soft T-shaped multi-layer stainless steel sheets on both sides to form a sealing ring has the dual advantages of metal hard seal and soft seal. It has zero leakage sealing performance at low and high temperatures.
The test proves that when the pool is in the positive flow state (the medium flow direction is the same as the disc rotation direction), the pressure on the sealing surface is generated by the torque of the transmission device and the effect of the medium pressure on the valve plate. When the positive medium pressure increases, the tighter the surface of the valve plate oblique cone and the valve seat sealing surface are pressed, the better the sealing effect. In the reverse flow state, the seal between the valve plate and the valve seat is pressed against the valve seat by the torque of the driving device. As the pressure of the reverse medium increases, 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 the tight pressure of the sealing surface of the valve plate and the valve seat Play the role of automatic compensation. Therefore, unlike the prior art, the utility model does not install soft and hard multi-layer sealing rings on the valve plate, but directly installs on the valve body. It is an ideal two-way hard sealing method to add an adjustment ring between the pressure plate and the valve seat. . It will replace gate valves, globe 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

related news /knowledge: How to choose the right butterfly valve (1); Detailed introduction of soft sealing butterfly valve-(3); Difference between soft seal butterfly valve and hard seal butterfly valve; 

How to choose the right butterfly valve (1)

When the butterfly valve is fully open to fully closed, it turns usually less than 90°. The butterfly valve and the butterfly stem itself have no self-locking capability. For the

U-type-flange-butterfly-valve-2

U-type-flange-butterfly-valve-2

positioning of the butterfly plate, a worm gear reducer must be installed on the valve rod. The use of worm gear reducer can not only make the butterfly plate self-locking, stop the butterfly plate at any position, but also improve the valve performance. The characteristics of industrial special butterfly valve: can withstand high temperature, the applicable pressure range is also high, the nominal diameter of the valve is large, the valve body is made of carbon steel, and the sealing ring of the valve plate uses a metal ring instead of a rubber ring. Large high-temperature butterfly valves are manufactured by welding steel plates, and are mainly used for flue gas ducts and gas pipes of high-temperature media.

Selection:
The butterfly plate of the butterfly valve is installed in the diameter direction of the pipeline. The butterfly valve is simple in structure, small in size and light in weight. It is composed of only a few parts, and can be quickly opened and closed only by rotating 90°. The operation is simple, and the valve has good fluid control characteristics. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the resistance when the medium flows through the valve body. Therefore, the pressure drop generated by the valve is very small, so it has good flow control characteristics.

If the butterfly valve is required to be used as a flow control, the main thing is to choose the valve size and type correctly. The structural principle of the butterfly

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

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

valve is especially suitable for making large-diameter valves. Commonly used butterfly valves are wafer-type butterfly valves and flanged butterfly valves. Wafer type butterfly valve is to use double-headed bolt to connect the valve between two pipeline flanges. Flange type butterfly valve is to use the process of connecting the flange of the valve to the pipeline flange with bolts.

The butterfly valve has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower, etc. as a component used to realize the on-off and flow control of the pipeline system. In the well-known butterfly valve technology, the sealing form mostly adopts a sealing structure, and the sealing material is rubber, polytetrafluoroethylene and the like. Due to the limitation of structural characteristics, it is not suitable for industries such as high temperature, high pressure, corrosion resistance and wear resistance.

An existing more advanced butterfly valve is a three-eccentric metal hard-sealed butterfly valve. The valve body and valve seat are connected components. The sealing surface layer of the valve seat is welded with temperature-resistant and corrosion-resistant alloy materials. The multi-layer soft stack type sealing ring is fixed on the valve plate. Compared with the traditional butterfly valve, this butterfly valve has high temperature resistance, is easy to operate, and has no friction when opening and closing. When closing, the torque is compensated with the increase of the torque of the transmission mechanism, which improves the butterfly valve. The sealing performance and the advantages of extended 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

Related news /knowledge: How to choose the right butterfly valve (2); Notes on selection and installation of butterfly valve; What is the material of the main parts of the butterfly valve?-(2)

Butterfly valve and its Development history – (2)

China’s valve industry chain is numerous, but it is not a valve power. Generally speaking, my country has entered the ranks of the world’s valve power, but from the perspective of product quality, my country still has a long gap from the valve power. The low production concentration of the industry, the low R&D capacity of

TH valve products

TH valve products

valves supporting high-end products, and the low level of manufacturing technology in the valve industry still exist, and the import and export trade deficit continues to expand. There are absolutely not so many valve companies that can really survive in the market. However, this high-speed shock in the valve industry will bring huge opportunities, and the result of the shock will make the market operate more rationally. The road to localization of high-end valves is unusually bumpy. Basic parts have become a short board that restricts the development of my country’s manufacturing industry to high-end. During the 12th Five-Year Plan period, the government will continue to increase the localization of high-end equipment parts. Here we select a few key mentioned in the “Implementation Plan” to develop a representative valve industry for import substitution feasibility analysis. It can be seen from the analysis that the feasibility of valve import substitution in various sub-industries varies greatly, and high-end valves urgently need more policy guidance and scientific research support.

The valve industry plays an important role in the development of the national economy as an important link in the equipment manufacturing industry. Since China’s domestic valve manufacturing level still has a certain gap compared with the international advanced level, many high-parameter, high-temperature, high-pressure, and high-pound key valves have always relied on imports. Relevant state departments in accordance with the national requirements for major equipment localization, A series of major deployments have been made successively, and led by the National Development and Reform Commission, the China National Machinery Industry Federation and the China General Machinery Industry Association have deployed and formulated a valve localization plan for major equipment in related fields, and have coordinated with relevant departments many times. Localization has formed a consensus in the domestic valve industry. Actively adopt international standards for product design; absorb foreign excellent design structures (including patented technology); product testing and performance inspection are strictly in accordance with international standards; absorb foreign production process experience and attach importance to the research and promotion of new materials; understand the high imports The technical parameters and working conditions of valve products are the way to speed up the process of localization, promote the continuous updating of valve products, and fully realize the localization of valves. With the acceleration of the reorganization of the valve industry, the future industry will be the competition between the quality and safety of valve products and product brands. The products are developing toward high technology, high parameters, strong corrosion resistance, and long life. Only through continuous technological innovation, development New products and technical transformations can gradually improve the technical level of products, meet the domestic equipment, and fully realize the localization of valves. Under the huge demand environment, my country’s valve manufacturing industry will surely present a better development prospect.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China. It was founded in 2006. Its predecessor was Tanghai Valve Manufacturing Factory. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Our main products: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…),

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

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Industry development prospects of check valve;
working principle of electric globe valve;
Knowledge;
Butterfly valve and its Development history – (1);

Butterfly valve and its Development history – (1)

Butterfly valve, also known as flap valve, is a kind of simple structure regulating valve, which can be used for the on-off control of low-pressure pipeline medium; is a kind of valve that the closing part (flap or disc) is a round plate, which rotates around the valve axis to achieve opening and closing.

The valve can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media.

U-type-flange-butterfly-valve-2

U-type-flange-butterfly-valve-2

Mainly cut off and throttle the pipe. The opening and closing part of butterfly valve is a disc-shaped butterfly plate, which rotates around its own axis in the valve body, so as to achieve the purpose of opening, closing or adjusting.

The butterfly valve was invented in the United States in the 1930s and introduced to Japan in the 1950s. It was only widely adopted in Japan in the 1960s, but its promotion in my country was after the 1970s. The main characteristics of butterfly valves are: small operating torque, small installation space and light weight. Taking DN1000 as an example, the butterfly valve is about 2T, while the gate valve is about 3.5T, and the butterfly valve is easy to be combined with various driving devices, and has good durability and reliability. The disadvantage of the rubber seal butterfly valve is that when it is used for throttling, improper use will cause cavitation, which will cause the rubber seat to peel off and damage. Therefore, how to choose it correctly depends on the working conditions.

The relationship between the opening of the butterfly valve and the flow rate basically changes linearly. If it is used to control the flow, its flow characteristics are also closely related to the flow resistance of the piping. For example, the diameter and form of the valves installed in the two pipelines are the same, and the pipeline loss coefficients are different, and the flow rate of the valve

Double flange butterfly valve (16)

Double flange butterfly valve (16)

will also be very different. If the valve is in a large throttle range, the back of the valve plate is prone to cavitation, which may damage the valve. Generally, it is used

outside 15°. When the butterfly valve is in the middle opening, the opening shape formed by the valve body and the front end of the butterfly plate is centered on the valve shaft, and the two sides are formed in different states. The front end of the butterfly plate on one side moves in the direction of the water flow, and the other side counters the direction of the water flow. Therefore, the valve body and the valve plate on one side form a nozzle-shaped opening, and the other side resembles an orifice-shaped opening. The flow rate on the nozzle side is much faster than the throttle side, and negative pressure will occur below the throttle side valve, often The rubber seal will come off. The operating torque of a butterfly valve has different values ​​depending on the degree of opening and the direction of valve opening and closing. Horizontal butterfly valves, especially large-diameter valves, due to water depth, the torque generated by the difference between the valve shaft and the water head can not be ignored. In addition, when the elbow on the inlet side of the valve forms a bias flow, the torque will increase. When the valve is in the middle opening, the operating mechanism needs to be self-locking due to the water flow torque.

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

Related news: The main classification methods of butterfly valve (1); Detailed introduction of soft sealing butterfly valve-(3)

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

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

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

Pneumatic actuator (2)

Pneumatic actuator (2)

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

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

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

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

pneumatic valve structure

pneumatic valve structure

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

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

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

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

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

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

TH Valve is one of the largest butterfly valve, check valve manufacturers in China. Now we have our own independent R & D, manufacturing,

assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services.

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

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Comparison of pneumatic actuator, electric actuator and hydraulic actuator;
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Pneumatic butterfly valve working principle diagram;

Structural characteristics of butterfly valve

The butterfly plate of the butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the valve body of the butterfly valve, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When it is rotated to 90°, the valve is fully opened.

The butterfly valve has a simple structure, small volume and light weight, and is composed of only a few parts. And only need to rotate 90 ° to quickly open and

U-type-flange-butterfly-valve-2

U-type-flange-butterfly-valve-2

close, simple operation, and the valve has good fluid control characteristics. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the single resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small, so it has good flow control characteristics. There are two types of butterfly valve: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded on the valve body or attached to the periphery of the butterfly plate.

Valves with metal seals generally have a longer life-time than valves with elastic seals, but it is difficult to achieve complete sealing. Metal seals can adapt to higher operating temperatures, while elastic seals have the disadvantage of being limited by temperature.

If the butterfly valve is required to be used as a flow control, the main thing is to choose the valve size and type correctly. The structure principle of the butterfly valve is especially suitable for making large-diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, and water treatment, but also in cooling water systems of thermal power stations.

Commonly used butterfly valves are wafer-type butterfly valves and flanged butterfly valves. Wafer type butterfly valve is to connect the valve between the two pipeline flanges with double-headed bolts. Flange type butterfly valve is to have a flange on the valve, and use bolts to connect the two ends of the valve to the pipeline flange. There are four types of butterfly valves in Tanghai Valve company, see below:

Butterfly Valve

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China. It was founded in 2006. Its predecessor was Tanghai Valve Manufacturing Factory. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services.

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

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