supplier Archives

Advantages and Features of Center-lined Wafer Butterfly Valve

December 15, 2021

The centerline wafer butterfly valve is a kind of centerline butterfly valve, which has two characteristics of wafer connection and centerline sealing. Today, the advantages and characteristics of the centerline wafer butterfly valve are based on the flange butterfly valve. details as follows:

Wafer type butterfly valve with worm gear

Pressure Level
The centerline wafer butterfly valve generally does not have a high pressure, and cannot be made with a higher pressure level like the flange butterfly valve. The nominal pressure of flanged butterfly valves is higher than that of wafer butterfly valves.

Install
During installation, the centerline wafer butterfly valve is generally installed with a matching flange, and the flange butterfly valve does not need to be equipped separately. The valve bolt length of the wafer butterfly valve will be longer, so the construction accuracy is higher. Because if the flanges on both sides are misaligned, the bolts will be subjected to greater shearing force, and the valve is prone to leakage.

Repair and maintenance
The centerline wafer butterfly valve generally cannot be used in the end of the pipeline and the downstream occasions that need to be disassembled, because when the downstream flange is removed, the wafer valve will fall. In this case, another short section must be made for disassembly. The flanged butterfly valve does not have the above problems, but the cost will be relatively high. The wafer butterfly valve has no flanges at both ends of the valve body, only a few guide bolt holes, and the valve is connected with the flange at the end by a set of bolts/nuts. In contrast, disassembly is more convenient, and the valve cost is lower, but the disadvantage is that one sealing surface has a problem, and both sealing surfaces have to be disassembled.
Due to installation reasons, if you encounter a situation where you need to install a blind plate, this situation is actually quite often encountered. In this situation, the midline wafer butterfly valve can only be installed with transitional pipe sections or replaced with other types of valves. It is impossible to disassemble the blind plate on the center line of the clamp butterfly valve. It is necessary to add a pair of flanges to the straight pipe section behind the valve after stopping, and at the same time add the figure 8 blind plate to avoid insufficient position when the blind plate is added in the future.

Better tightness
The centerline wafer butterfly valve has a poorer sealing effect than the flange butterfly valve. For example, the transportation of slurry media causes blockage. The advantage of the center line to clamp butterfly valve is that it is easy to disassemble and assemble, but it will leak if it is not installed well. Flanged butterfly valves are expensive. The valve is equipped with flanges. The flanges on both ends of the valve are connected to the pipe flanges with bolts. The sealing performance is better than that of the clamp butterfly valve. Flange butterfly valves are easier to make eccentricity, and multiple eccentricities can achieve excellent sealing performance, but it is not easy to achieve a wafer butterfly valve. If the centerline wafer butterfly valve is a soft sealing butterfly valve, the rubber liner damage cannot be repaired on site, but the flange type can be repaired.

In summary, the centerline wafer butterfly valve has low cost and strong adaptability to installation space. The disadvantage is that the sealing performance is not as good as the eccentric butterfly valve and the flange butterfly valve, and the disassembly and maintenance will be slightly more troublesome than the flange butterfly valve. Under the condition that the medium pressure is not particularly high and the working conditions are ordinary, the centerline wafer butterfly valve is still a good choice from the comprehensive examination of cost, sealing performance, installation and maintenance.

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

Video of center-lined butterfly valve:

Precautions for installation of pinless wafer butterfly valve

December 14, 2021

The pinless wafer butterfly valve contains two connection methods, one is pinless and the other is wafer. A pinless butterfly valve is a pinless butterfly valve that does not use a pin to penetrate the connection between the valve plate and the valve stem. For comparison of pin butterfly valves and pinless butterfly valves, please refer to valve knowledge. The wafer butterfly valve is connected between two pipe flanges with stud bolts, without flanges.

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

Commonly used pinless butterfly valves include wafer type butterfly valves and flange type butterfly valves, so flange type butterfly valves are often compared with wafer type butterfly valves. The biggest difference between the two is the connection method during installation. Now let’s take a look at what to pay attention to when installing the pinless wafer butterfly valve.
1. During installation, the valve disc should be stopped in the closed position.
2. The opening position should be determined 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. The installation should be carried out according to the installation instructions of the manufacturer, and the heavy-weight butterfly valve should be installed with a firm foundation.
5. The butterfly plate of the pinless wafer butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0-90°. When the rotation reaches 90°, the valve is fully open.
6. If the butterfly valve is required to be used as a flow control, the main thing is to select the size and type of the valve 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 used in cooling water systems of thermal power stations.
The price of the pinless wafer butterfly valve is roughly 2/3 of that of the pinless flange butterfly valve, which is relatively cheap, but the sealing performance is not as good as that of the flange butterfly valve. When choosing imported valves, use wafer butterfly valves as much as possible because they are cheap and light in weight. One of its limitations is that there are no flanges at both ends of the valve body, and there are only a few guide bolt holes. The valve is connected to the end flange with a set of bolts/nuts. Compared with the flanged butterfly valve, it is much more convenient to disassemble, and the valve cost is lower, but the disadvantage is that one sealing surface has a problem, and both sealing surfaces have to be disassembled. The paired flanges of the clip-on type are butt welded and cannot be installed by socket welding.
The pinless wafer butterfly valve also has its own advantages, that is, it saves space, and try to use wafer butterfly valves when the piping position is tight. The biggest difference between the pinless wafer butterfly valve and the flangeless butterfly valve is that the wafer butterfly valve saves a pair of flanges, so the cost is relatively cheap, but it is not conducive to the disassembly and assembly of maintenance, etc., where permitted, priority Choose a wafer butterfly valve. Wafer butterfly valves are generally used in industrial pipelines with relatively low pressure and relatively safe transport media.

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
Video of center-lined butterfly valve:

Is the EPDM butterfly valve suitable for water medium?

December 13, 2021

EPDM rubber butterfly valve fully meets the water working conditions and is a kind of soft sealing butterfly valve. It has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical properties, oil-filling properties and fluidity at room temperature. It can be used in ozone-resistant, weather-resistant, and ultraviolet-resistant applications, but based on its own structural characteristics, EPDM butterfly valves have poor flame retardancy, oil resistance and adhesion. Now let’s take a look at the specific performance of EPDM butterfly valve:

wafer type butterfly valve, EPDM seat (10)

1. Low density and high filling:
The seat material of EPDM butterfly valve is a kind of rubber with lower density. A large amount of oil and filler can be added, so it can reduce the cost of rubber products, make up for the high price of EPDM rubber, and the physical and mechanical properties of the valve seat sealing surface are not greatly reduced after high filling.
2. Aging resistance:
EPDM butterfly valves have a common feature of rubber that is not resistant to high temperatures. It can be used for a long time at 120 ℃, and can be used briefly or intermittently at 150 to 200 ℃. However, manufacturers now also try to add suitable antioxidants to increase the temperature of the valve, and the EPDM butterfly valve cross-linked with peroxide can be used under more severe conditions.
3. Corrosion resistance:
EPDM butterfly valves have good resistance to various polar chemicals, such as alcohols, acids, alkalis, oxidants, refrigerants, detergents, animal and vegetable oils, ketones and greases. But it has poor stability in gasoline, benzene, etc. and mineral oil. Therefore, it is not suitable for oil, and its performance will decrease under the long-term action of concentrated acid.
4. Water vapor resistance:
EPDM butterfly valve has excellent performance in water vapor resistance. It is much higher than the performance of fluorine rubber, silicon rubber, fluorine silicon rubber, butyl rubber, nitrile rubber, and natural rubber under the same conditions.
5. Superheated water resistance:
The superheated water EPDM butterfly valve is also no problem, the mechanical properties change very little, and the volume expansion rate is low, but it is closely related to the vulcanization system used.
6. Electrical performance:
Compared with styrene butadiene rubber, polyethylene and cross-linked polyethylene, the electrical performance of EPDM butterfly valve is very close or even better, and it has good electrical insulation and corona resistance.
7. Flexibility:
In terms of elasticity, EPDM butterfly valves are second only to natural rubber and butadiene rubber, and can still be maintained at low temperatures.
8. Adhesion:
Due to the lack of active groups in the molecular structure of EPDM, the cohesive energy is low, and the rubber is easy to bloom, and its self-adhesiveness and mutual adhesion are very poor.

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

Video of center-lined butterfly valve: https://youtu.be/NuSZH_AJcwY

How to choose the material of flanged gate valve seat

December 10, 2021

The sealing surface of flanged gate valve is an important working surface for the valve to block the medium and control the fluid. The quality of the sealing surface determines whether the valve is guaranteed to have no internal leakage, impermeability and other direct influence factors, which can be said to determine the service life of the valve. If the sealing surface is damaged, the valve will not work properly. Among them, the material selection of the sealing surface is a very important factor, and it is very important to guarantee the quality of the sealing surface. Therefore, the following factors should be considered when selecting the valve sealing surface material:

AWWA C509-C515-resilient seated gate valve-DN600-150lb (2)

1. Corrosion resistance
Whether the medium is pure water or other, it will cause certain corrosion to the flanged gate valve. The surface of the sealing surface will inevitably be damaged under the action of the high-speed passage of the medium. Delaying this process is our primary consideration when selecting sealing surface materials. Once the surface of the sealing surface is damaged, the sealing performance of the valve cannot be guaranteed, and the medium will easily leak from the damaged part of the sealing surface. Therefore, the sealing surface material must be corrosion resistant. The corrosion resistance of a material mainly depends on the chemical stability of the material. But secondly, we must consider the medium conditions to see if it matches the sealing material.
2. Friction resistance
Because the medium and the sealing surface move relative to each other, and it is a high-speed process, damage to the material due to friction is inevitable. Such damage will eventually inevitably cause damage to the sealing surface. Therefore, the sealing surface material must have good friction resistance, especially for flanged gate valves. The wear resistance of the sealing material is often determined by the internal properties of the material. At the same time, pay attention to the valve installation location to meet the needs.
3. Erosion resistance
The image of the erosion phenomenon is a process in which the sealing surface is destroyed when the medium flows through the sealing surface at a high speed. This kind of damage is more obvious in the throttle valve used in high temperature and high pressure steam medium, because it needs to be opened and closed frequently, which has a great impact on the damage of sealing. Therefore, erosion resistance is also one of the important requirements of the sealing surface material.
4. The sealing surface of flanged gate valves should have a certain degree of hardness, and the hardness will drop greatly under the specified working temperature.
5. The linear expansion coefficient of the sealing surface of the gate valve and the body material should be similar, which is more important for the structure of the inlaid sealing ring, so as to avoid excessive stress and loosening at high temperatures.
6. When used under high temperature conditions, it must have sufficient anti-oxidation, thermal fatigue resistance and thermal cycling.
When faced with real working conditions, it is difficult to find a sealing surface material that fully meets the above requirements. It is appropriate to match and choose according to different valve types and uses. There are several key points such as: often need to open and close, or in high-speed medium, the sealing material of flanged gate valve used here should be specially marked with erosion resistance requirements, and if it contains solid impurities, the hardness should be selected The higher the sealing surface material, the better the durability.

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

Video of resilient seated gate valve: https://youtu.be/AI-LT1dy2sU

Evolution of the Sealing Surface of the Triple Eccentric Butterfly Valve

December 9, 2021

The triple eccentric butterfly valve is one of the butterfly valves. Its unique sealing form and sealing structure are continuously improved and upgraded through the product to obtain a better sealing effect. There have been great reforms in high temperature and corrosion resistance. Let’s take a look at its product upgrade process.

triple offset butterfly valve-double flange- (5)

The butterfly valve’s single eccentric soft-seal butterfly valve is the first to be favored by the market. Because of the design of the soft seal, the product has a good sealing effect. Single eccentricity means that the sealing section of the valve seat is eccentric relative to the center of rotation of the valve stem, so that the sealing surface of the butterfly plate gradually separates from the sealing surface of the valve seat during the opening process. When the butterfly plate rotates to 20-25, the sealing surface of the butterfly plate is completely separated from the sealing surface of the valve seat, so that the relative mechanical wear and extrusion between the two sealing surfaces of the butterfly valve is greatly reduced during the opening process, and the sealing performance of the butterfly valve is improved. This design mainly relies on the elastic deformation of the squeezing between the butterfly plate and the valve seat to ensure the sealing of the butterfly valve.
In order to meet the needs of the site, to achieve the effect that the sealing surface of the butterfly plate is separated from the sealing surface of the valve seat faster than the single eccentric structure, the double eccentric sealing butterfly valve is upgraded on the basis of the single eccentric butterfly valve. The lines are relatively offset, so that the butterfly valve forms a cam effect during the opening process. When the butterfly plate rotates to 8°~12°, the two sealing surfaces can be completely separated. The biggest benefit of this structural design is to further reduce the mechanical wear and extrusion deformation between the two sealing surfaces, which improves the sealing performance of the butterfly valve and increases the lifespan.
The triple eccentric sealing butterfly valve is once again upgraded on the basis of the double eccentric butterfly valve. The center line of the seat sealing surface and the valve center line form an angular eccentricity, and a third eccentricity appears. In this way, during the opening process, the sealing surface of the butterfly plate can be separated from the sealing surface of the valve seat immediately, and will contact and compress the sealing surface of the valve seat at the moment of closing. This unique eccentric design makes full use of the benefits of the cam, so that the mechanical friction and scratches between the two sealing surfaces of the butterfly valve seal pair can be completely eliminated when opening and closing, so that the possibility of wear and leakage is eliminated. The product changes the extrusion seal into a torque seal. By adjusting the external driving torque, the adjustment of the seal specific pressure is realized, so that the sealing performance and service life of the triple eccentric structure sealing butterfly valve are greatly improved. At the same time, while ensuring a tight seal, it also improves the characteristics of the sealing sub-materials of the single-eccentric soft-seal butterfly valve and the double-eccentric soft-seal butterfly valve that cannot withstand high temperature and wear.
Now, the triple eccentric sealing butterfly valve is widely used as the best device to cut off or adjust the flow of the medium pipeline in the urban construction, petrochemical, metallurgy, electric power and other industries. Its structure itself is the most ideal opening and closing part in pipelines, and it is the development direction of today’s pipeline opening and closing parts. If you need butterfly valve products, look for Tanghai Valve. 24 years of experience in butterfly valve production is more assured.

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
Video of triple eccentric butterfly valve: https://youtu.be/AkRwg2X1Wh0

What is a triple eccentric metal seated butterfly valve

November 30, 2021

The triple eccentric metal seated butterfly valve is classified from the multi-level metal seated butterfly valve. Named because of the triple eccentricity structure. Its sealing performance is as good as the soft sealing butterfly valve, and it can maintain a good seal even in a high-pressure and high-temperature environment. It is often used for heating, gas, and gas, oil, acid and alkali environments, and appears in industrial pipelines such as petrochemical, food, medicine, textile, paper, electricity, sewage treatment, water supply and drainage, and smelting. A variety of gas, liquid, semi-fluid and micro-particle powder transportation pipelines or containers also play an important role. In more and more sites, it has gradually begun to replace electric gate valves and stop valves. And the installation position of the triple eccentric metal seated butterfly valve can be arbitrary, which is very convenient.

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

Let’s take a look at its structural characteristics and principle of action:
1. The difference between the triple eccentric metal seated butterfly valve and the ordinary butterfly valve is the triple eccentric design structure. The advantage of this structure is that there is less friction and no wear during the opening and closing process, which greatly extends the service life of the valve. The disc installation center and the rotation center are designed with a strict eccentricity.
2. The valve seat of this product is embedded with O-shaped rubber ring or fluorine plastic as the sealing gasket. This greatly compensates for the lack of tight sealing of the hard seal butterfly valve, while retaining the advantage of strong applicability of the hard seal. When the medium pressure is introduced into the sealing groove, the product seal squeezes the valve seat sealing surface to the butterfly plate under pressure to seal the valve. This unique sealing structure makes the greater the pressure, the stronger the sealing force.
3. The advantage of the triple eccentric metal seated butterfly valve is also reflected in the later maintenance. Once the sealing ring leaks, the valve can be fine-tuned to the required size by the adjusting screw to the direction of the butterfly plate without disassembling the valve, and the sealing performance of the new valve can be regained, which is a very valuable advantage.
4. In addition to the manual type, the product also has three categories and six series of products such as pneumatic and electric, which fully meets the needs of the site.
On the occasion of use, the triple eccentric metal seated butterfly valve is very suitable for working conditions where the temperature is high and leakage is not allowed, and the medium is impure and impurity, such as cement plants and power plants. And the sealing can be improved by surfacing the sealing surface and improving the strength of the valve seat. If the working conditions allow certain leakage, the ventilation butterfly valve is better to use. Tanghai Valve independently develops, produces and sells various butterfly valve products, including hard-sealed butterfly valves, flanged butterfly valves, electric butterfly valves, pneumatic butterfly valves, pipe network butterfly valves and many other products. Welcome to visit our factory.

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 prevent the motor of electric flange butterfly valve from overloading

November 29, 2021

The torque and axial force of the valve electric actuator are limited, so usually the valve electric device uses a torque-limiting coupling. Most of the torque type is three-jaw connection or key connection, and the valve electric device does not bear the axial thrust. Most of the thrust type is threaded connection, which can bear larger axial thrust. What determines the execution torque of an electric actuator? It is mainly determined by the specifications of the electric device. The overload operation of the electric flange butterfly valve motor is actually a manifestation of the working torque of the motor being higher than the control torque. The following several situations may cause the motor to run at an overload, which needs our attention.

Double flange butterfly valve (16)

1. When the power supply voltage is low and the required torque cannot be obtained, stop the motor;
2. Wrongly adjust the torque limit mechanism to make it larger than the stopping torque, causing continuous excessive torque and stopping the motor;
3. Using intermittently, the heat accumulation generated exceeds the allowable temperature rise value of the motor;
4. For some reason, the torque limit mechanism circuit breaks down, the torque is too large and the ambient temperature is too high, and the thermal capacity of the motor is relatively reduced, which may cause the motor to overload.
5. The motor model does not match the requirements of the electrical equipment, and the actual output torque does not have enough corresponding margin, which may cause damage to the motor during overload operation.
Generally speaking, there are two ways to protect the motor: one is to judge the increase or decrease of the input current of the motor; the other is to judge the heating of the motor itself. The basic protection method to prevent the motor from overloading is: using a thermostat to protect the motor from continuous operation or jog operation; using a thermal relay to protect the motor from stalling; using a fuse or overcurrent relay for short-circuit accidents. Most electrical equipment manufacturers connect the stroke and torque protection in series. When over-travel or over-torque, the micro switch cuts off the AC contactor coil control power in time, thereby cutting off the main circuit of the motor. Or there is a temperature control switch in the motor. When the valve motor is over-torque or running for a long time, the temperature of the motor rises. When the temperature exceeds the set temperature value, the temperature control switch immediately cuts off the control circuit to protect the motor.
During operation, the rotation direction of the handwheel of the electric device is always the same as the rotation direction of the output shaft, clockwise is to close the valve, and counterclockwise is to open the valve. If the actual rotation direction of the motor does not conform to the regulations, any two phases of the three-phase power supply need to be replaced. Otherwise, the protection measures will be ineffective and the motor will be damaged due to reverse phase.

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

Common leakage problems and remedies of resilient-seated gate valves

November 26, 2021

The resilient seated flange gate valve is an updated product of the gate valve, because the gate plate is wrapped by elastic materials such as rubber or PTFE, or the valve seat is made of elastic material. In short, one of the valve seat and the valve plate can be regarded as soft seal. The combination of soft and hard sealing can achieve zero leakage. And because the connection form is flange connection, hence the name. It is widely used in fluid pipelines such as

AWWA C509-C515-resilient seated gate valve-DN600-150lb (2)

tap water, sewage, construction, petroleum, chemical industry, food, medicine, textile, electric power, shipbuilding, metallurgy, energy system, etc. The soft sealing flange gate valve is characterized by low fluid resistance, wide applicable pressure and temperature range, unlimited medium flow direction, and good sealing performance.
In procurement, the leakage inspection of resilient seated flange gate valves is always the first concern. understand the product’s tightness, we first understand which components of the gate valve are prone to leaks, so that we can achieve good prevention and remedial measures. details as follows:
1. Leakage occurs at the junction of the gate valve and the gate valve
If this happens, first check whether the connecting bolts between the gate valves are tightened. This is to ensure that the inner gasket ring is fully integrated with the flange sealing groove surface. If a leak has occurred here, you can check the bolts and nuts in order and tighten them to the compression seal ring. Finally, check the size and accuracy of the gasket ring and the flange sealing groove surface, whether there is a bit of corrosion, sand holes, sand holes or impurities, and corresponding repair welding, repair or cleaning according to the situation.
2. The valve cover is leaking
Valve cover leakage is usually caused by the leakage of packing seals. If there is such a problem with the seal, you can check the selection first. If the selection of the seal and the sealing groove do not match, it is easy to leak. This problem can be solved by replacing the sealing ring or repairing the sealing groove. The appearance of burrs, fracturing, twisting, etc. of the seals may also cause leakage and need to be replaced in time. Finally, check whether the sealing surface of each sealing groove is rough or have other defects. If there are defects, remove the defects or update the damaged parts. Special attention should be paid to the packing installation situation and the matching surface of the packing seal. To check the installation of these packings, it is found that the upper and lower packings are installed upside down and need to be removed and reinstalled according to the correct method.
3. Leakage on the surface of the valve body cavity
In this case, the valve body may have sand holes, sand holes and other casting defects during the casting process, which are difficult to be found before the pressure test. But once pressure is applied, leakage will occur in these places. This kind of problem is to be repaired, repaired or updated.
4. Leakage at the valve seat gate
This is also a relatively common leakage phenomenon. There are two cases of leakage of the sealing surface and leakage of the root of the sealing ring. We can start by checking the accuracy of the sealing surface. It is too rough and needs to be removed and reground. Secondly, check whether the sealing surface has defects such as pitting, indentation, blisters, cracks, etc., and pay attention to the replacement of the gate or valve seat. Sometimes some valve seats with compression springs will leak due to the weakening of the compression spring’s elasticity. In addition, attention should be paid to whether the T-shaped connection between the valve plate and the valve stem is too loose. If there is a slope, it should be adjusted to its better size immediately.
5. Leakage caused by the entry of debris
If foreign matter such as welding slag, iron filings, impurities enter the valve body, it will also cause the valve plate to close to the expected depth and cause leakage. In this case, the valve body must be removed and cleaned.
6. Leakage caused by improper installation of valve seat
Special tools should be used to install the valve seat. If the valve seat is not installed in place, leakage will occur.

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 select electric actuator of the electric regulating butterfly valve

November 25, 2021

The valve electric actuator is an important driving force of the electric regulating butterfly valve, and its selection determines the actual on-site operation of the product. At the same time, the selection of electric actuators has some own selection criteria. Mainly from the operating torque, host structure, output shaft rotation, output speed, etc. to consider, more detailed principles will be shared below:
1. The operating torque is an important parameter for selecting the valve electric device. The output torque of the electric actuator should be 1.2 to 1.5 times the larger operating torque of the valve.

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

2. The main structure of the valve electric device is divided into two types: without thrust plate and with thrust plate. The main difference between the two is whether the torque is directly output or converted by the stem nut in the thrust plate.
3. The number of rotations of the output shaft is related to the nominal diameter of the valve, the pitch of the stem, and the number of thread heads. The total number of rotations that the electric device should meet = valve opening height/stem thread head number X valve Rod drive thread pitch.
4. The diameter of the optional valve stem must be allowed to pass by the electric device. That is to say, the inner diameter of the hollow output shaft of the electric device must be larger than the outer diameter of the stem of the rising stem valve. At the same time, in order to ensure that the electric regulating butterfly valve can work normally after assembly, the diameter of the valve stem and the size of the keyway need to be selected appropriately.
5. The output speed needs to be appropriate. If the opening and closing speed of the valve is too fast, water hammer is likely to occur. So choose according to the usage.
The above are the problems that need to be paid attention to in the selection of the electric valve electric actuator of the electric regulating butterfly valve. In terms of packaging and transportation, there are also some points to pay attention to regarding valve electrical equipment. First of all, the packaging of electrical equipment such as valve electric actuators should be protected from rain, moisture, and dust, and the packaging should be firm and reliable. After receiving the goods, they should be installed immediately. If it needs to be placed for a period of time, the storage environment should be kept ventilated and dry, and it should not be stored in the open air. At the same time, it is forbidden to carry out debugging and maintenance on cloudy and rainy days. After the pressure test is completed, re-tighten all the firmware to ensure that the electrical part is tightly sealed to prevent corrosion loss and affect later use.
The valve electric actuator of the electric regulating butterfly valve is an indispensable device for the realization of valve program control, automatic control and remote control. Its movement process is controlled by the stroke, torque or axial thrust. The correct selection of valve electric devices is essential to prevent overload. For more information about electric butterfly valves, please consult the online customer service of Tanghai Valve’s official platform. You are welcome to visit and purchase.

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

Field Application of Electric resilient seated Wafer Butterfly Valve

November 22, 2021

The electric resilient seated butterfly valve is actually a kind of electric control valve system. It is a high-performance valve upgraded from the ordinary butterfly valve category. It also uses electrical operation during operation. Therefore, the most obvious advantage of the electric resilient seated butterfly valve is that it is quite simple and easy to control.

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

In today’s society, various electrified operating systems have replaced old equipment, electrification and intelligence are no longer unfamiliar words to us. To keep up with the rapid development of the valve industry, constant humane upgrades are essential. In the past, companies had to set up manpower specifically for valve operation and management, but now the birth of electric resilient seated butterfly valves allows companies to no longer consume this cost. It has unique structure, flexible operation, labor saving and convenient. If the sealing material is matched with stainless steel and nitrile oil-resistant rubber, the service life can be effectively extended.
In terms of composition, the electric resilient seated wafer butterfly valve is composed of wafer butterfly valve and small electric actuator. Its structure is compact, and it is easy to switch by 90°. Its valve body material is usually cast iron, ductile iron, stainless steel, copper alloy, aluminum alloy. Disc materials are usually: ductile iron, stainless steel, corrosion-resistant steel, titanium steel, copper alloy. The valve seat material is usually nitrile nitrile, ethylene propylene, neoprene, Hypolon, polytetrafluoroethylene, natural rubber, etc. The choice of material makes the valve more sealed and reliable, and it is widely used in water supply and drainage systems such as water plants, power plants, steel plants, papermaking, chemical industries, and catering, as adjustment and cut-off use. While saving manpower, it greatly reduces the damage to working conditions and personnel. For example, in some special toxic or polluting working conditions, the electric resilient seated wafer butterfly valve does not require long-term contact by personnel, but only a light switch. , So the humanized management is a great improvement.
The reason why the electric resilient seated wafer butterfly valve can have such a good development in modern times is due to the increase of valve export products, so the market also puts forward higher requirements for valve standards. Valve quality and sales channels have become key competitive factors. Therefore, while competing for channels, manufacturers pay more attention to product technology research and development, quality, packaging, and delivery period will have higher requirements. In the future, the production process and R&D process of electric resilient seated wafer butterfly valve products will be more closely integrated with environmental protection and energy.

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

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