butterfly valve factory Archives

Flange telescopic butterfly valve application | advantages and disadvantages | installation instructions

June 10, 2021

Flange telescopic butterfly valve application|advantages and disadvantages|installation instructions
Flange telescopic butterfly valve application:
The butterfly plate of the flange telescopic butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the telescopic butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully opened. Applicable temperature≤80℃, used in petroleum, chemical, food, medicine, textile, papermaking, electric power, water supply and drainage, gas pipelines, as the function of regulating flow and intercepting medium, and has the function of compensating for thermal expansion and contraction of pipelines.

Double flange butterfly valve (16)

Advantages and disadvantages of flange telescopic butterfly valve:
Flange retractable butterfly valve (the structural length can be extended within a certain range), which not only brings convenience for valve disassembly, but also relieves pipeline stress and protects the valve. At the same time, it also condenses the installation method of butterfly valve plus retractor, and space More compact. Normally, this type of valve does not require special maintenance, and only needs to be regularly observed for leakage and pull-off in the telescopic part. The initial cost of flange expansion butterfly valve is lower than the installation method of flange butterfly valve plus expansion, but considering the maintenance cost in the future, the gain is not worth the loss.
If the sealing part of the butterfly valve is damaged and the sealing ring cannot be replaced and the butterfly valve needs to be scrapped, then the telescopic part will be scrapped together, resulting in greater loss. For example, when the sealing part of the butterfly valve needs maintenance, only the compression and expansion part cannot realize the valve-free online maintenance. However, the installation method of the butterfly valve and the expansion device has a great advantage. Only the expansion device needs to be removed, that is, manual Large maintenance space to realize valve free maintenance (butterfly valve is heavy, retractor is light, and labor intensity is low).
Precautions for installation of flange telescopic butterfly valve:
1. It is strictly forbidden to disassemble the butterfly valve of the disintegrated telescopic flange at the pipeline construction site; it is strictly forbidden to lengthen and shorten the telescopic butterfly valve repeatedly at the site.
2. The pipes at both ends of the telescopic valve must be concentric, and the two flange surfaces on the pipe must be parallel;
3. Flange fixing bolts should be tightened symmetrically, please do not forcibly tighten flange fixing bolts unilaterally;
4. The telescopic tube is installed behind the valve;
5. The expansion part of the expansion valve shall not be installed at the corner of the pipeline or at the end of the pipeline.
6. The telescopic flange butterfly valve must be placed flat before installation, and do not bump it at will;
7. The structural length of the telescopic flange butterfly valve is the minimum length when it leaves the factory, and when installed, it is pulled to the installation length (ie the design length);
8. When the length between the pipelines exceeds the installation length of the telescopic butterfly valve, please adjust the pipeline interval and do not force the telescopic valve to avoid damage to the telescopic valve;
9. The butterfly valve of the telescopic flange butterfly valve can be installed at any position. When used for temperature compensation, after the installation of the pipeline, brackets should be added along the two ends of the pipeline axis to prevent the telescopic valve telescopic tube from being pulled out. The support force of the bracket is calculated according to the following formula , It is strictly forbidden to remove the bracket during operation;
10. The telescopic flange butterfly valve does not do temperature compensation. At the same time, it is only used for installation, replacement, and maintenance. When the valve is convenient for use, it can be limited by bolts, and the telescopic flange butterfly valve can be clamped symmetrically to prevent the telescopic tube from being pulled out and damaging the telescopic butterfly valve and piping devices or buildings. Things. The bolt diameter can be calculated according to the flange bolt diameter, its bolt strength and test pressure and pipeline tension, according to the above formula. The limit bolts are strictly prohibited to be removed during operation (bolts are provided separately).

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 and analysis of the performance of the wafer butterfly valve

July 20, 2020

With the same nominal pressure and nominal diameter, ordinary which has better tightness and is not easy to leak? butterfly valve or gate valve?

wafer type butterfly valve, NBR seat (11)

The airtightness of the gate valve is better than that of the butterfly valve, but there are also manufacturers’ butterfly valves that have better airtightness.
The gate valve is large in size and takes up a lot of space.
The butterfly valve is small in size and takes up little space.

When selecting concretely, the temperature of the medium, the sealing of the valve and the packing should also be considered.
The specification stipulates that the butterfly valve with a nominal diameter greater than 50 is used.

Wafer butterfly valve is a national key new product. The high-performance manual butterfly valve adopts a double eccentric and a special oblique cone oval sealing structure. It solves the shortcoming of the traditional eccentric butterfly valve that the sealing surface is still in sliding contact friction at the moment of opening and closing 0°～10°, and the sealing surface of the butterfly plate is separated at the moment of opening, and the effect of sealing when the contact is closed is achieved to extend the service life and maximize the sealing performance.

Tanghai Valve is the best manufacturer of wafer-type butterfly valve in China. We produce the best quality products with competitive low prices.

13 gate-valve-5

Our products use advanced manufacturing technology, and strictly conform to API, DIN, BS, EN, GB and other international standards. The main products are butterfly valves, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…), etc. Our products are widely used in various fields such as marine industry, shipbuilding, petrochemical, metallurgy, water treatment, fire fighting, water supply and drainage, etc. The company has won unanimous recognition and praise from customers with high quality and good reputation.

We have established long-term and stable business relationships with many multinational companies. Our products are exported to Europe, the United States, Australia, and the Middle East, Southeast Asia and other countries and regions. The quality of our products has been widely recognized by customers, and has been trusted and praised by customers. Gradually we have established a close technical partnership with customers from various countries.

We are committed to “Build a top valve enterprise; Be a reliable partner!”

Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

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

Notes on selection and installation of butterfly valve

July 17, 2020

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

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 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 the right butterfly valve (2)

July 13, 2020

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,

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 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 the right butterfly valve (1)

July 13, 2020

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

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

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

The main classification method of butterfly valve (2)

July 10, 2020

According to the connection method, the butterfly valve can be devided into four or five types:

1. Wafer type butterfly valve

Wafer type butterfly valve with worm gear

The butterfly plate of the wafer butterfly valve is installed in the diameter direction of the pipeline. The valve is fully open.
Wafer type butterfly valve has simple structure, small volume and light weight. 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.

2. Lug butterfly valve

2 lug-type-butterfly-vlave-6

The butterfly plate of the lug butterfly valve is installed in the diameter direction of the pipeline. The butterfly plate rotates around the valve shaft, and the rotation angle is between 0°-90°. When it rotates to 90°, the valve is fully open.

3. Flanged butterfly valve

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

Double flange butterfly valve (4)

The flanged butterfly valve has a vertical plate structure, and the valve stem is an integral type. Metal hard seal, valve sealing ring
It is a composite structure of flexible graphite plate and stainless steel plate, which is installed on the valve body, and the sealing surface of the butterfly plate is welded with stainless steel. The sealing ring of the soft seal valve is made of nitrile rubber, EPDM or VITON, and is installed on the butterfly plate. The sealing seat of the centerline sealed flange butterfly valve is directly fusion bonded on the valve body.
Flanged butterfly valves are divided into U-shaped butterfly valves and double-flanged butterfly valves according to the length of the structure. The U-type butterfly valve has a relatively short face to face structure, which reduces the weight of the valve body and saves space for use.

4. Welded butterfly valve
Welded butterfly valve is a non-hermetic butterfly valve, widely used in the construction materials, metallurgy, mining, electric power and other production processes, the medium temperature ≤300 ℃, the nominal pressure is 0.1Mpa pipeline, used to communicate, open or close or adjust the medium volume.

The electric regulating butterfly valve belongs to a variety of electric valves and electric regulating valves. The main connection methods are: flange type and wafer type, which are important execution units in the field of industrial automation control. Two major analysis points for the installation points of the electric adjustment butterfly valve: the installation position, height, and inlet and outlet directions must meet the design requirements. Note that the direction of the medium flow should be consistent with the direction of the arrow marked on the valve body, and the connection should be firm and tight. Before installing the electric butterfly valve, a visual inspection must be carried out. The nameplate of the valve should comply with the provisions of the current national standard “General Valve Mark” GB12220. For valves with a working pressure greater than 1.0 MPa and acting as a shut-off on the main pipe, a strength and tight performance test should be carried out before installation. Use only after passing the test. 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. The electric adjustable butterfly valve can be divided into offset plate type, vertical plate type, inclined plate type and lever type according to the structural form; according to the sealing form, it can be divided into two types: soft seal type and hard seal type; soft seal type generally adopts rubber ring seal, hard seal type Usually a metal ring seal is used.

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

The advantages and disadvantages of butterfly valves

July 10, 2020

Advantages of butterfly valve:

1. Convenient opening and closing, labor saving, low fluid resistance, and can be operated frequently.

wafer type butterfly valve, NBR seat (11)

2. The structure is simple, the external dimensions are small, the structural length is short, the volume is small, and the weight is light. It is suitable for valves with large diameter.

3. Mud can be transported, and the least liquid is accumulated in the pipe mouth.

4. Under low pressure, a good seal can be achieved.

5. Good adjustment performance.

6. When fully opened, the effective flow area of the valve seat channel is large, and the fluid resistance is small.

7. The opening and closing torque is small, because the butterfly plates on both sides of the rotating shaft are basically the same under the action of the medium, and the direction of generating torque is opposite, so the opening and closing are more labor-saving.

8. The sealing surface material is generally rubber, plastic, so the low-pressure sealing performance is good.

9. Easy installation.

10. Flexible and labor-saving operation, you can choose manual, electric, pneumatic, hydraulic mode.

Disadvantages of butterfly valve:

1. The operating pressure and operating temperature range are small.

2. Poor sealing.

Butterfly valves can be divided into offset plate type, vertical plate type, inclined plate type and lever type according to the structure.

According to the sealing form, it can be soft-sealed or hard-sealed. The soft seal type generally uses a rubber ring seal, and the hard seal type usually uses a metal ring seal.

According to the connection type, it can be divided into flange connection and wafer connection; according to the transmission mode, it can be divided into manual, gear transmission, pneumatic, hydraulic and electric.

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

Posts

Flange telescopic butterfly valve application | advantages and disadvantages | installation instructions

Comparison and analysis of the performance of the wafer butterfly valve

Notes on selection and installation of butterfly valve

How to choose the right butterfly valve (2)

How to choose the right butterfly valve (1)

The main classification method of butterfly valve (2)

The advantages and disadvantages of butterfly valves

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