supplier Archives

Advantages of the handle butterfly valve of Tanghai valve manufacturer

March 8, 2022

What are the advantages of handle butterfly valve? To understand this, let’s first understand the handle butterfly valve. The handle butterfly valve is a kind of manual butterfly valve. The common materials for making the handle butterfly valve are gray cast iron, ductile iron, cast steel, stainless steel, etc. The handle butterfly valve is the most common pipeline accessory in the pipeline system. It is generally required to be installed horizontally, and the

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

butterfly plate of the handle butterfly valve is installed in the diameter direction of the pipeline. The switch operation is also very simple and convenient. Rotate the handle, the handle drives the valve stem to rotate, and the circular butterfly plate rotates around the valve stem. Usually, it is turned on by turning counterclockwise, and turned off by turning clockwise. The rotation angle is 0°-90°. Between °, when the disc rotates to 90°, the valve is fully open.
The handle butterfly valve has a simple structure and small volume. It can be seen in the water treatment, urban water supply and drainage, petroleum, chemical industry, and even the cooling water system of the thermal power station.

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

Tanghai Valve is committed to providing high-quality valve products and services to the society. The handle butterfly valve has always been our flagship product and one of the most satisfied products for customers. So in the highly competitive valve market, what are the advantages of the handle butterfly valve of Tanghai valve manufacturers?

1. Different handle design
The handle end of the handle butterfly valve adopts a humanized arc structure, which will not let the operator hurt his hand during operation, and it is more labor-saving to open and close.

2. Stainless steel handle bolts and disc pins
The bolts used on the handle and the pins on the butterfly plate are all made of stainless steel, and the corrosion resistance is more than 10 times that of ordinary products, making it safer to use.

3. Reinforcement at both ends of the butterfly plate
In order to prevent the instantaneous impact of the flowing medium to break the butterfly plate after the butterfly valve is installed, four reinforcing ribs are specially added at both ends of the butterfly plate.

4. Valve seat for vulcanization process
In order to ensure the sealing performance of the valve, the valve seat adopts the vulcanization process, which makes the valve seat and the valve body fit better, and the sealing surface is wider, which is more reliable than the sealing performance of ordinary butterfly valves.

5. Valve body painted with epoxy paint
If the butterfly valve is installed outdoors, the valve body is exposed, and it is easy to rust, which affects the service life of the valve. For this reason, Tanghai Valve specially sprays the valve body with epoxy resin paint, which makes the valve body of the butterfly valve more resistant to oxidation and can be safely installed outdoors.

6. Pressure test higher than the national standard
Each butterfly valve of Tanghai Valve must pass a pressure test higher than the national standard before leaving the factory.

7. Universal universal valve body
Tanghai Valve’s wafer butterfly valve adopts universal universal body, which can meet the national standard, German standard, American standard, Japanese standard, Korean standard, British standard and other standards at the same time, so as to meet the needs of different customers.

8. The natural rubber content of the valve seat exceeds 40%
The natural rubber content of the valve seat of the soft sealing butterfly valve is more than 40%, which has a longer service life than ordinary rubber.

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:

Structural characteristics and suitable medium of soft sealing gate valve

March 7, 2022

Structural characteristics of soft sealing gate valve:

Gate valves are mainly used in water-passing pipelines, but traditional gate valves may leak or corrode during use, which affects the performance of gate valves. As an upgraded product of traditional gate valves, the emergence of soft-sealed gate valves solves the problems of traditional gate valves that are easy to leak, easy to rust, and have poor elasticity. This article will give an introduction to the structural characteristics of soft sealing gate valves.

AWWA C509-C515-resilient seated wedge gate valve-DN80-150lb (4)

Soft sealing gate valve can be divided into dark rod soft sealing gate valve and rising rod soft sealing gate valve according to the structure. The working principle of the two structures is the same, the difference lies in the valve body structure, installation space, application range and so on. Details will be shared with you in future articles.

The structural characteristics of soft sealing gate valve are:
1. The valve body is made of ductile iron, which is lighter in weight and more conducive to installation and maintenance than traditional gate valves.
2. The valve body is coated with powder epoxy resin, which can play an anti-oxidation effect, prevent the valve body from being corroded, and is not easy to rust.
3. The traditional gate valve seat has grooves at the bottom. After the medium flows through, impurities in the medium such as stones, wood chips, iron chips and other debris will deposit and accumulate in the grooves at the bottom of the valve seat, which will cause the gate to fail to close completely over time. , causing leakage. The bottom of the valve seat of the soft-sealed gate valve is a flat-bottom design, and the medium containing impurities will not be precipitated and deposited when the valve body flows through, which ensures the sealing performance.
4. The gate of the soft-sealing gate valve is covered with high-quality rubber as a whole. The rubber and the gate are firmly attached, not easy to fall off, and have elastic memory, so that the gate and the valve seat can be tightly sealed to achieve good sealing performance. .

What medium is suitable for soft sealing butterfly valve:

In the introduction of the previous article, we learned that the sealing performance of the soft-sealed butterfly valve is superior, and it can achieve two-way sealing and zero leakage. The suitable media for soft seals are air, water, steam, various corrosive media, mud, oil, etc.
Butterfly valve can be divided into soft sealing butterfly valve and hard sealing butterfly valve according to the different sealing surface materials. The sealing surface refers to the valve seat of the butterfly valve. The sealing surface materials of the soft-seal butterfly valve we often see are EPDM, nitrile and PTFE. The three types of soft-sealed butterfly valves of different materials are also different in the applicable medium in the pipeline.

EPDM
Also called EPDM, codenamed EPDM. EPDM rubber is the most commonly used valve seat material for soft-seal butterfly valves, and it is also widely used. In the working environment of normal temperature and pressure, the use of EPDM valve seats has very good sealing performance. And EPDM rubber is resistant to ozone, aging, and has a long service life. The soft-sealed butterfly valve with EPDM as the valve seat material is suitable for fresh water, sewage, seawater and similar mud and other media containing impurities.

Nitrile
Nitrile-butadiene rubber, code-named NBR, has one of the biggest features of this material is its oil resistance is particularly good, in addition to a certain degree of wear resistance and heat resistance. The soft-sealed butterfly valve uses nitrile rubber as the sealing surface material, which can be used in oil pipelines and oily media. In addition, nitrile rubber is not suitable for medium such as fresh water, because it contains certain toxicity, which will cause harm to human health.

Teflon
PTFE is a fluoroplastic, code-named PTFE. The characteristics of PTFE are resistance to various acids and alkalis and various organic solvents; PTFE is used as the soft sealing partner of the valve seat material, which is mainly used in chemical industry, oil refining, chemical fiber, phosphate fertilizer, non-ferrous smelting, acid production, dyeing and other industries In the field, the applicable media are all corrosive strong acid and strong alkali media.
It can be seen from the above introduction that the soft sealing butterfly valve has a wide range of media and can be used in many fields. However, the soft sealing butterfly valve also has certain defects. Because of its own sealing material, it is not suitable for high temperature, high pressure and severe erosion conditions. In addition, in order to ensure the sealing performance of the soft-sealed butterfly valve, regular maintenance of its sealing surface should also be noted.

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:

lug type dual plate check valve for marine industry-seawater

February 28, 2022

The dual plate check valve is divided into 3 types: Wafer type dual plate check valve, lug type dual plate check valve and double flanged dual plate check valve.

Classification of lug dual plate check valves: hard-seal lug dual plate check valve and soft-seal lug dual plate check valve; of which soft-seal lug check valve is divided into full-lined soft-seal lug check valve and Semi-lined/normal soft-seal lug dual plate check valve.

lug type dual plate check valve for marine industry-seawater (1)

lug dual plate check valve is used for pure pipelines and industrial, environmental protection, water treatment, high-rise building water supply and drainage pipelines, to prevent the reverse flow of the medium. The check valve adopts a clamp type, the butterfly plate is two semicircles, and it adopts a spring for forced reset. The sealing surface can be built-up welding wear-resistant material or rubber lining, with a wide range of use and reliable sealing.

The check valve opening and closing parts are opened or closed automatically by the flow and force of the medium to prevent the medium from flowing back. The valve is called the check valve. Check valves belong to the category of automatic valves, which are mainly used in pipelines where the medium flows in one direction, and only allow the medium to flow in one direction to prevent accidents.

According to the structure of the check valve, it can be divided into three types: lift check valve, swing check valve and butterfly check valve. Lift check valves can be divided into two types: vertical and horizontal. Swing check valves are divided into three types: single valve, double valve and multi valve. The butterfly check valve is a straight-through type. The above-mentioned check valves can be divided into three types in connection form: threaded connection, flange connection and welding. A check valve is a valve that can automatically prevent fluid from flowing back. The disc of the check valve is opened under the action of fluid pressure, and the fluid flows from the inlet side to the outlet side. When the pressure on the inlet side is lower than that on the outlet side, the valve flap is automatically closed under the action of the fluid pressure difference, its own gravity and other factors to prevent the fluid from flowing back.

lug type dual plate check valve for marine industry-seawater (2)

Model: H76X/H76H/H76W
Name: lug dual plate check valve
Please refer to the main technical parameters and spare parts materials:
https://www.tanghaivalve.com/wafer-type-double-disc-swing-check-valve-introduction/
Product name: lug double plate check valve (soft seal)
National Standard Number: H76X

Size range: DN40-DN1200
Pressure rating: PN10/16/25/40/64/100
Valve features: double valve plate design, short running track of the valve plate, spring load makes the valve plate close more quickly, effectively preventing water hammer
When the valve plate is opened, it is close to 90 degrees, and the pressure loss is small
Zero leakage
Size range: 2″ to 48″
Pressure range: 10bar-50 bar
Suitable flange: National standard or EN1092 PN10/PN16/PN25/PN40 or ANSI 125/150/300
Structure length: EN558 series 16, API594

Material of lug type dual plate check valve:

name	materials
Valve body	gray cast iron, ductile iron, carbon steel, stainless steel, aluminum bronze
Valve disc	ductile iron nickel-plated, stainless steel 201, stainless steel 304, stainless steel 316, aluminum bronze
Valve stem	WCB, 2Cr13, Stainless steel, Monel, duplex steel, steel alloy.
Valve seat	Rubber, stainless steel, steel alloy, Super Duplex Steel
Spring	60Si2Mn、3Cr13、17-7PH、INCONEL

Uses: Suitable for installation at the outlet of high-lift pumps, or as a bottom valve in front of the pump, suitable for water, sea water, steam, oil, chemicals, chlorine, oxygen, and steam. Can be installed horizontally or vertically.
Application scope:
It is suitable for industrial, environmental protection, sewage treatment, high-rise building water supply and drainage pipelines, etc. It can also be used for environmental systems with corrosive media such as power plants and steel plants gypsum slurry.

Features of lug dual plate Check Valve:

Simple structure and light weight, especially suitable for low-pressure large-diameter pipelines;
The paired clamp connection mode, the production process is simple, and the disassembly and assembly are convenient;
The check valve adopts the clamp type, the butterfly plate is two semicircles, and the spring is forced to reset. The sealing surface can be built-up welding wear-resistant material or rubber lining, with a wide range of use and reliable sealing.

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

What is the reason for the poor sealing of the valve

February 17, 2022

Where there is a pipeline, the valve is inseparable. The valve is installed on the pipeline and controls the flow of the fluid medium in the pipeline. It is an important control component. But the valve is also a wearable part. A common valve loss in our life is that the valve is not tightly sealed, resulting in leakage. So what is the reason for the poor

marine valve seat

sealing of the valve?
The leakage at the packing of the valve is a part of the valve that is prone to leakage failures. The valve is not tightly sealed, and the reasons are probably as follows.
1. Sealing auxiliary structure
Under the change of temperature or sealing force, the structure of the sealing pair will change. And this change will affect and change the force between the sealing pair, so that the performance of the valve sealing is reduced. Therefore, when choosing a seal, be sure to choose a seal with elastic deformation. At the same time, pay attention to the width of the sealing surface. The reason is that the contact surfaces of the sealing pair cannot be completely matched. When the width of the sealing surface increases, the force required for sealing is increased.
2. Specific pressure of sealing surface
The specific pressure of the sealing surface affects the sealing performance of the valve and the service life of the valve. Therefore, the specific pressure of the sealing surface is also a very important factor. Under the same conditions, too high specific pressure will cause valve damage, but too low specific pressure will cause valve leakage. Therefore, we need to fully consider the appropriateness of the specific pressure when designing
3. Physical properties of the medium
The physical properties of the medium also affect the valve sealing performance. These physical properties include temperature, viscosity, and hydrophilicity of the surface, among others. The temperature change not only affects the slackness of the sealing pair and the change of the size of the parts, but also has an inseparable relationship with the viscosity of the gas. Gas viscosity increases or decreases with increasing or decreasing temperature. Therefore, in order to reduce the influence of temperature on the sealing performance of the valve, when designing the sealing pair, we should design it as a valve with thermal compensation such as an elastic valve seat. Viscosity is related to the permeability of the fluid. When under the same conditions, the higher the viscosity, the lower the permeability of the fluid. The hydrophilicity of the surface means that when there is a film on the metal surface, the film should be removed. Because of this very thin oil film, it will destroy the hydrophilicity of the surface, resulting in blockage of fluid channels.
4. The quality of the sealing pair
The quality of the sealing pair mainly means that we must check the selection, matching and manufacturing accuracy of materials. For example, the valve disc fits well with the valve seat sealing surface, which can improve the sealing performance. The characteristic of many circumferential waviness is that its labyrinth sealing performance is good.

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:

Knife Gate Valve Structure and Working Principle

February 16, 2022

Knife gate valve, also called knife type gate valve, is a kind of gate valve. The structural feature of the knife gate valve is that there is an oblique cut at the bottom of its valve plate. Like a knife edge, this knife-shaped oblique cut can easily cut off the medium circulating in the pipeline, so that the valve can be closed without being blocked by the medium. Below is the structure diagram of the knife gate valve.

Knife gate valve (6)

Knife gate valves are generally used in medium pipelines such as pulp, slag, coal ash, sewage, and chemical raw materials. They can only be fully opened and fully closed. They are used as shut-off valves and cannot be used for flow regulation. The transmission modes of the knife gate valve are manual, pneumatic, electric, etc., and its working principle is also very simple. The following takes the manual knife gate valve as an example to introduce the working principle of the knife gate valve to you.
The working principle of the manual knife gate valve is to turn the handwheel by hand to make the valve stem rise or fall, thereby driving the gate to move up and down to achieve the purpose of opening or closing the valve. Turn the handwheel clockwise, the gate goes down, and the valve closes. Turn the handwheel counterclockwise, the gate rises, and the valve opens.
Compared with the traditional gate valve, the structure of the knife gate valve is simpler, the length and size are smaller, and it is easier to install, disassemble and maintain. Knife gate valves are suitable for use in medium pipelines with high consistency and solid particles. The gate like a guillotine has a better gate breaking effect, and can effectively cut off various impurities contained in the medium in the pipeline, completely solving the leakage phenomenon of the traditional gate valve after passing through the medium containing particulate impurities.
Knife gate valves have very short structural lengths and take up little space. The full-bore knife gate valve design allows the valve to be used in dirty media, and the replaceable seat and packing also make valve maintenance easier.
Although the performance of the knife gate valve is better than that of the traditional gate valve, the price of the knife gate valve is higher than that of the traditional gate valve, so the knife gate valve cannot completely replace the traditional gate valve at present.

Knife gate valve installation and use:
1. Before installation, check the valve cavity and sealing surface, and do not allow dirt or sand to adhere;
2. The bolts of each connecting part should be tightened evenly;
3. Check that the packing parts are required to be pressed tightly, not only to ensure the sealing of the packing, but also to ensure the flexible opening of the gate;
4. Before installing the valve, the user must check the valve model, connection size and pay attention to the flow direction of the medium to ensure the consistency with the valve requirements;
5. When installing the valve, the user must reserve the necessary space for the valve drive;
6. The wiring of the drive device must be carried out according to the circuit diagram;
7. The knife gate valve must be maintained regularly, and must not be collided and squeezed at will, so as not to affect the sealing.

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 knife gate valve:

What is the principle of triple eccentric butterfly valve

February 11, 2022

Triple eccentric butterfly valve is a kind of butterfly valve with outstanding performance in industrial pipelines. According to the sealing form, triple eccentric butterfly valve belongs to the category of hard sealing butterfly valve. Therefore, the triple eccentric butterfly valve has the characteristics of a hard-sealed butterfly valve, which is

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

resistant to high temperature, erosion, and has a long service life. And because the triple eccentric butterfly valve directly welds the high temperature corrosion resistant alloy material on the valve seat surface, the valve also has the same excellent sealing performance as the soft sealing butterfly valve. So what is the principle of triple eccentric butterfly valve? What are the three eccentricities of the triple eccentricity? Why use a triple eccentric structure?

The sealing surface of the triple eccentric butterfly valve is an inclined conical surface. The valve seat of the valve body is in contact with the sealing ring of the butterfly plate. Its working principle is to drive the movement of the butterfly plate by operating the transmission device. During the movement of the butterfly plate, its sealing The ring is in full contact with the valve seat because of the elastic deformation to achieve the seal.
A prominent feature of the triple eccentric butterfly valve is that the sealing structure of the valve is changed. It is no longer a traditional position seal, but a torsion seal, that is to say, it does not rely on the elastic deformation of the valve seat to achieve sealing, but relies on the sealing surface of the butterfly plate. The contact surface pressure with the valve

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

seat is used to achieve the sealing effect, which also solves the problem of large leakage of the metal valve seat, and because the contact surface pressure is proportional to the medium pressure, the triple eccentric butterfly valve has a strong high pressure and high temperature resistance.

Three eccentric butterfly valve three eccentric
The first eccentricity: the deviation from the plane of the sealing surface to the centerline of the valve stem;
The second eccentricity: the distance from the centerline of the valve body to the centerline of the stem;
The third eccentricity: there is an included angle between the center line of the cone surface where the sealing surface of the valve body is located and the center line of the valve body channel.

Reasons for using triple eccentric structure
The use of triple eccentric structure can reduce the friction between the sealing surface of the disc and the sealing surface of the valve body when opening or closing, so that the disc can quickly disengage or release the valve seat when the triple eccentric butterfly valve is opened or closed, reducing the operation time. torque, the operation is more labor-saving and light, and the service life of the sealing surface of the butterfly valve is increased.

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:

Properties of triple eccentric butterfly valve

February 10, 2022

Performance advantages of triple eccentric butterfly valve:
1. It integrates adjustment and cut-off, and has strong controllability.
The design of the new triple eccentric butterfly valve adopts a double safety structure. In order to prevent the deformation of the disc, the dislocation of the valve stem, and the occlusion of the sealing surface caused by the

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

influence of fluid pressure and temperature, two independent stoppers are installed on the upper and lower sides of the disc. The push ring ensures the normal operation of the valve under any working conditions; in order to prevent the valve stem from being damaged and flying out and causing unexpected accidents, independent valve stem flying-out prevention mechanisms are designed at the lower end of the valve inside and outside.
2. No dead zone design, small opening torque.
The shape of the valve plate of the triple eccentric butterfly valve is an elliptical cone, and its surface is surfacing with hard alloy, which has excellent wear resistance. The floating U-shaped stainless steel valve seat has the function of automatically adjusting the center. When the valve is opened, the valve plate of the elliptical cone sealing surface is first separated from the U-shaped elastic valve seat, and then rotated; when the valve is closed, the valve plate rotates, and the valve plate automatically adjusts the center to the elastic valve seat under the action of the eccentric shaft. Seat pressure deforms the seat until the seat is in close contact with the oval conical sealing surface of the valve plate. When the valve is switched on and off, the disc does not scratch the valve seat, the torque of the valve stem is directly transmitted to the sealing surface through the disc, and the opening torque is small, thus eliminating the common jumping phenomenon when opening the valve, that is, eradicating the dead zone (no sense band) . This design without dead zone enables the triple eccentric butterfly valve to enter the controllable area almost from 0 opening to 90 opening, and its control ratio can be as high as 1001 or more, which is twice that of ordinary butterfly valves.
3. Zero leakage, high temperature and high pressure resistance.
The biggest feature of triple eccentricity is that it fundamentally changes the sealing structure. It is no longer a position seal, but a torsion seal, that is, it does not rely on the elastic deformation of the valve seat, but completely relies on the contact surface pressure of the valve seat to achieve the sealing effect. This sealing structure enables the triple eccentric butterfly valve to achieve a hard seal of level VI and achieve true zero leakage. At the same time, due to the selection of the metal valve seat and the structural characteristics of the face seal, the problem of high temperature and high pressure resistance is also easily solved. In addition, the triple eccentric butterfly valve adopts the body seat structure, which makes the valve structure more compact, and reduces the chance of the valve seat directly contacting the medium, reduces the degree of erosion of the valve seat, and can effectively prevent small solids in the medium. The impact of the material and thermal expansion may cause the sealing surface to bite, thereby extending the service life of the valve seat. The new triple eccentric butterfly valve can not only replace the body seat, but also the disc sealing surface and disc are independent, and the disc sealing surface can also be replaced, which greatly reduces the maintenance cost.

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:

Advantages and Disadvantages of Triple Eccentric Butterfly Valves

January 21, 2022

The triple eccentric butterfly valve is a new type of butterfly valve product. Before the advent of the triple eccentric butterfly valve, the soft sealing butterfly valve and the single eccentric double eccentric metal hard sealing butterfly

triple eccentric butterfly valve-

valve were the most used in industrial pipelines. These two types of butterfly valves have their own advantages, but also have obvious disadvantages. The advantage of soft sealing butterfly valve is that it has good sealing performance and can achieve zero leakage; the disadvantage is that it is not suitable for high temperature and high pressure environment and is not resistant to wear. The advantage of hard sealing butterfly valve is that it can adapt to high temperature and high pressure working conditions, but the sealing performance is very poor. In order to solve the shortcomings of the two types of butterfly valves and better serve our production work, the triple eccentric butterfly valve came into being and has been widely used.

Advantages of triple eccentric butterfly valve
The triple eccentric butterfly valve also belongs to the metal hard sealing butterfly valve. The technology makes the triple eccentric butterfly valve more resistant to high temperature and high pressure environment and more corrosion resistant than traditional butterfly valve products. At the same time, due to the unique design of the triple eccentricity, the valve is very easy to operate. When opening and closing, the disc and the valve body have no friction. When the valve is closed, the torque of the transmission mechanism increases to provide a compensation seal, which greatly improves the triple eccentricity. The sealing performance of the butterfly valve also prolongs the service life of the butterfly valve. So what do the three eccentricities of the triple eccentricity mean?
1st eccentric: The valve shaft is located behind the valve plate shaft, allowing the seal to have a complete tight encircling contact with the entire valve seat.
The second eccentricity: the centerline of the valve shaft is offset from the centerline of the pipe and valve, which is free from the interference of valve opening and closing.
3rd eccentricity: The valve seat cone shaft is offset from the centerline of the valve shaft, which eliminates friction during closing and opening and achieves a uniform compression seal around the entire valve seat.

Disadvantages of triple eccentric butterfly valve
No matter how perfect things are, there will be more or less defects and imperfections, and the triple eccentric butterfly valve is no exception. Its shortcomings have the following two points:
1. Due to the special process of the triple eccentric butterfly valve, the structure of the butterfly plate will be relatively thick, so if a butterfly valve with a triple eccentric structure is used on a small-diameter pipeline, the resistance of the butterfly plate to the circulating medium in the pipeline will be very large in the open state, and the flow of The resistance is large, so generally speaking, the triple eccentric butterfly valve is not suitable for small diameter pipelines below DN200.
2. In the normally open pipeline, the sealing surface of the valve seat of the triple eccentric butterfly valve and all layers of the sealing ring on the butterfly plate will be washed by the front, which will affect the sealing performance of the valve for a long time.

The above is the introduction of Tanghai valve for the advantages and disadvantages of triple eccentric butterfly valve. If you have purchase requirements for triple eccentric butterfly valves, you are welcome to inquire.

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

Video of triple eccentric butterfly valve:

Which valves are used for wastewater and sewage treatment

January 20, 2022

Which valves are used for wastewater and sewage treatment? The continuous increase of water pollution in my country has made the sewage treatment and regeneration industry receive unprecedented attention. In the sewage treatment pipeline system, the valve plays a very important role.

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

Definition of sewage treatment
Sewage treatment: The process of purifying sewage in order to make it meet the water quality requirements for discharge into a body of water or for reuse. Sewage treatment is widely used in construction, agriculture, transportation, energy, petrochemical, environmental protection, urban landscape, medical treatment, catering and other fields, and is increasingly entering the daily life of ordinary people.

Sewage treatment classification
According to the classification of sewage sources, sewage treatment is generally divided into production sewage treatment and domestic sewage treatment. Production sewage includes industrial sewage, agricultural sewage and medical sewage, etc., while domestic sewage is sewage generated in daily life, which refers to the complex mixture of various forms of inorganic and organic substances, including: ① floating and suspended solid particles; ② glue shape and gel-like diffusion; ③ pure solution.
According to the quality of water pollution, there are two types of water pollution: one is natural pollution; the other is man-made pollution. At present, man-made pollution is the most harmful to water bodies. Water pollution can be divided into three categories: chemical pollution, physical pollution and biological pollution according to the different pollution impurities. The main pollutants are: (1) industrial wastewater discharged without treatment; (2) domestic sewage discharged without treatment; (3) farmland sewage with extensive use of chemical fertilizers, pesticides, and herbicides; (4) industrial waste and domestic garbage piled up by the river ; ⑸ soil erosion; ⑹ mine sewage.

Sewage treatment valve
Modern sewage treatment technology can be divided into primary, secondary and tertiary treatment according to the degree of treatment. Generally, the degree of sewage treatment is determined according to the water quality and the destination of the treated water. The valves used at each level are also different.
primary treatment
It mainly removes suspended solid pollutants in sewage, and most of the physical treatment methods can only complete the requirements of primary treatment. After primary treatment of sewage, BOD can generally be removed by about 30%, which does not meet the discharge standard. The primary treatment belongs to the preprocessing of the secondary treatment. Valves and their pipeline accessories are used: knife gate valve, triple eccentric butterfly valve, filter, etc.
secondary processing
It mainly removes colloidal and dissolved organic pollutants (BOD, COD substances) in the sewage, and the removal rate can reach more than 90%, so that the organic pollutants can meet the discharge standard, and the suspended solids removal rate can reach 95%, and the effluent effect is good. The valves used are soft-sealed butterfly valves, gate valves, ball valves, check valves, etc.
tertiary treatment
Further treatment of refractory organic matter, nitrogen and phosphorus and other soluble inorganic matter that can lead to eutrophication of water bodies. The main methods are biological denitrification and phosphorus removal, coagulation sedimentation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis. The valves used are wafer butterfly valve, gate valve, ball valve, check valve, rubber soft joint, etc.

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
Video of triple eccentric butterfly valve: https://youtu.be/AkRwg2X1Wh0
Video of dual plate wafer check valve: https://youtu.be/XqRRI7o-LFI
Video of knife gate valve: https://youtu.be/vFSbTF_FGXM
Video of resilient seated gate valve: https://youtu.be/AI-LT1dy2sU

Introduction to Common Butterfly Valve Materials

January 14, 2022

This article makes an introduction to the commonly used butterfly valve materials. For butterfly valves, you should already have a certain understanding. There are many types of butterfly valves. According to the different connection forms, they can be divided into wafer butterfly valves and flanged butterfly valves; according to different sealing surface materials, they can be divided into soft sealing butterfly valves and metal hard sealing. Butterfly valve;

Types of wafer butterfly valves

according to the different driving methods, it can be divided into handle butterfly valve, turbine butterfly valve, pneumatic butterfly valve, electric butterfly valve and so on. So what are the commonly used butterfly valve materials?
Commonly used butterfly valve materials are mainly cast iron, cast steel, stainless steel three categories. Each material can be further subdivided. Below we will give an introduction to these three types of butterfly valve materials.

Category 1: Cast Iron
Cast iron is subdivided into four categories: gray cast iron, malleable cast iron, ductile iron, and nickel cast iron. This article mainly introduces the two main cast iron materials made by Tanghai valve: gray cast iron, ductile iron and stainless steel.

lug butterfly valve-lined-PTFE-DI body (1)

Gray cast iron is cast iron with flake graphite, because the fracture is dark gray when broken, so it is called gray cast iron. Gray cast iron is the most widely used cast iron, and its output accounts for more than 80% of the total output of cast iron. The casting performance, cutting performance and wear resistance of gray cast iron are very good. Its disadvantage is that its strength, plasticity and toughness are lower than other cast irons.
Grey cast iron is used as the material of butterfly valve, which is usually suitable for weak acid and weak alkali media such as water and air, but not suitable for pipelines with perhydrochloric acid and nitric acid media.
Ductile iron is a high-strength cast iron material with very high strength, toughness and wear resistance, and its comprehensive performance is close to that of steel. At present, the application range of ductile iron is second only to gray cast iron. We often say “replace steel with iron”, which refers to ductile iron.

U type flange butterfly valve (4)

Ductile iron is used as the material of butterfly valve, which has certain corrosion resistance and performance is much higher than that of butterfly valve made of gray iron. The applicable medium includes steam, general gas and oil.

The second category: cast steel
Cast steel is a cast iron alloy, which is a general term for iron-based alloys used to produce castings that do not undergo eutectic transformation during solidification. The advantages of cast steel are greater design flexibility and variability, increased overall structural strength and a wide range of weight variations. Using cast steel as the butterfly valve material, the performance is better than that of cast iron but not as good as stainless steel. Butterfly valve made of cast steel is suitable for steam, non-corrosive gas, oil, etc.

The third category: stainless steel
Stainless steel refers to steel that is resistant to weak corrosive media such as air, steam, and water, and chemically corrosive media such as acid, alkali, and salt, also known as stainless acid-resistant steel. Generally, the butterfly valve made of stainless steel has the best performance and can be used in more severe working conditions. It is used in some ultra-high temperature, ultra-low temperature and strong acid-base corrosive medium pipelines. Wear-resistant and long-lasting.

The above is the introduction of commonly used butterfly valve materials. Generally speaking, the price of stainless steel butterfly valve is the highest, and gray cast iron is the cheapest. If you want to know more about butterfly valve, you are welcome to visit Tanghai Valve”

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:

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