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Characteristics of ball valve

August 14, 2020

Features of ball valve:
1. Wear resistance; because the valve core of the hard-sealed ball valve is spray-welded alloy steel,

ball valve (2)

The sealing ring is made of alloy steel surfacing, so the hard sealing ball valve will not produce too much wear when opening and closing. (Its hardness coefficient is 65-70):

Second, the sealing performance is good; because the sealing of the hard-seal ball valve is manually ground, it can be used until the valve core and the sealing ring are completely matched. So his sealing performance is reliable.

3. The switch is light; since the bottom of the sealing ring of the hard-sealed ball valve adopts a spring to make the sealing ring and the valve core tightly hug together, the switch is very light when the external force exceeds the preload of the spring.

4. Long service life: It has been widely used in petroleum, chemical industry, power generation, papermaking, atomic energy, aviation, rockets and other departments, as well as people’s daily life.

The pneumatic ball valve has a simple and compact structure, reliable sealing, and convenient maintenance. The sealing surface and the spherical surface are always in a closed state, which is not easy to be eroded by the medium. It is easy to operate and maintain. It is suitable for general working media such as water, solvent, acid and natural gas. It is mainly used for cutting off. Or connect the medium in the pipeline, and can also be used for fluid adjustment and control.

Compared with other types of valves, pneumatic ball valves have angular stroke output torque, quick opening, stable and reliable, wide application, and the following advantages:

1. The thrust bearing reduces the friction torque of the valve stem, which can make the valve stem operate smoothly and flexibly for a long time.

2. Anti-static function: a spring is set between the ball, valve stem and valve body, which can lead out the static electricity generated during the switching process.

3. Since materials such as polytetrafluoroethylene have good self-lubricating properties and small friction loss with the ball, the pneumatic ball valve has a long service life.

4. Small fluid resistance: Pneumatic ball valves have the smallest fluid resistance among all valve categories. Even the reduced diameter pneumatic ball valves have relatively small fluid resistance.

5. Reliable valve stem sealing: Since the valve stem only rotates and does not move up and down, the packing seal of the valve stem is not easy to be damaged, and the sealing ability increases with the increase of the medium pressure.

6. Good sealing performance of the valve seat: The sealing ring made of elastic materials such as polytetrafluoroethylene is easy to seal in structure, and the valve sealing capacity of the pneumatic ball valve increases with the increase of the medium pressure.

7. The fluid resistance is small, and the full-bore ball valve basically has no flow resistance.

8. Simple structure, small size and light weight.

9. Close and reliable. It has two sealing surfaces, and the sealing surface materials of the ball valve are widely used in various plastics, which have good sealing performance and can achieve complete sealing. It has also been widely used in vacuum systems.

10. Convenient operation, rapid opening and closing, only need to rotate 90° from fully open to fully closed, which is convenient for remote control.

11. Convenient maintenance, simple structure of the ball valve, generally movable sealing ring, easy to disassemble and replace.

12. When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium. When the medium passes, it will not cause erosion of the valve sealing surface.

13. It has a wide range of applications, with a diameter ranging from a few millimeters to a few meters, and can be applied from high vacuum to high pressure.

14. Because the ball valve has wiping properties during opening and closing, it can be used in media with suspended solid particles.

15. The processing precision is high, the cost is expensive, and it is not suitable for use in high temperature. If there are impurities in the pipeline, it is easy to be blocked by the impurities, causing the valve to fail to open.

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 a ball valve?

August 14, 2020

A ball valve is a valve in which the opening and closing parts (ball) are driven by the valve stem and rotate around the axis of the ball valve. It can also be used for fluid adjustment and control.

14 ball-valve-6

Ball valves are divided into pneumatic ball valves, electric ball valves, and manual ball valves according to the driving mode. In China, ball valves are widely used in petroleum refining, long-distance pipelines, chemicals, papermaking, pharmaceuticals, water conservancy, electric power, municipal administration, steel and other industries.

Product description of ball valve:
Ball valve came out in the 1950s. With the rapid development of science and technology, the continuous improvement of production technology and product structure, in just 40 years, it has rapidly developed into a major valve category. In developed western countries, the use of ball valves is increasing year by year.

In my country, ball valves are widely used in petroleum refining, long-distance pipelines, chemicals, papermaking, pharmaceuticals, water conservancy, electric power, municipal administration, steel and other industries, and occupy a pivotal position in the national economy. It has the action of rotating 90 degrees, and the cock body is a sphere with a circular through hole or channel passing through its axis.

The ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. It only needs to rotate 90 degrees and a small torque to close tightly. The ball valve is most suitable for use as a switch and shut-off valve, V-shaped ball valve. In addition to paying attention to pipeline parameters, electric valves should also pay special attention to the environmental conditions in which they are used. Since the electric device in the electric valve is an electromechanical device, its use status is greatly affected by its use environment. Under normal conditions, special attention should be paid to the use of electric ball valves and butterfly valves in the following environments.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest ball valve manufacturers in China, main products are butterfly valves, check valves, gate valve and globe valves. Key words: 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…)

Knife gate valve introduction and its characteristics

August 14, 2020

Knife gate valve entered China in the 1980s. In less than two decades, its use has expanded from ordinary fields to a

Knife gate valve (1)

wider range of industries, from coal preparation, gangue discharge, and slag discharge in mines and power plants to Urban sewage treatment has evolved from general industrial pipelines to specialized pipeline systems for food, sanitation, and medicine.

What is a knife gate valve:
Knife gate valve-also known as knife door valve, knife-type slurry valve, entered my country in the 1980s. In less than two decades, its scope of use has expanded from the general field to a wider range of industries. Coal preparation, gangue discharge and slag discharge from mines and power plants. It has developed into urban sewage treatment, from general industrial pipelines to professional pipeline systems such as food, sanitation, and medicine. The ultra-thin knife gate valve completely solves the large flow resistance of ordinary gate valves, flat gate valves, ball valves, globe valves, regulating valves, butterfly valves and other valves with its advantages of small size, small flow resistance, light weight, easy installation, and easy disassembly. , Heavy weight, difficult installation, large area and other difficult problems. After the emergence of knife gate valves, a large number of general shut-off valves and regulating valves have been replaced. To date, the world’s largest consumption of knife gate valves is the United States and Japan.

Characteristics of knife gate valve:

Knife gate valve-

1. Valve control can be used for local and remote control, and can also realize remote position display and remote centralized control according to user requirements.

2. Light weight: The body is made of carbon steel, and the weight is about 20%-30% lighter than the traditional gate valve. It is easy to install and maintain.

3. The use of this valve can improve the closing and sealing performance of the conveying pipeline system, prevent leakage to the maximum extent, and play a positive role in improving production efficiency and protecting the environment.

4. The sealing surface is made of highly wear-resistant and corrosion-resistant ceramic materials, and the use of inlay technology has high corrosion resistance and good wear resistance, so that the valve has a long life and the cost performance is 10 times higher than that of ordinary 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

Gate valve characteristics and installation notes

August 13, 2020

Gate valve characteristics:
Light weight
The body is made of high-grade nodular cast iron, the weight is about 20%~30% less than the weight of traditional

13 gate-valve-5

gate valve, and the installation and maintenance are convenient.

Flat bottom brake seat:
Traditional gate valves often silt in the grooves at the bottom of the valve due to foreign objects such as stones, wood, cement, iron filings, sundries, etc., after the pipe is washed with water, which can easily cause water leakage. The bottom of the gate valve is sealed by elastic seating. It adopts the same flat-bottom design as the water pipe machine, which is not easy to cause debris accumulation and makes the fluid flow unimpeded.

Overall encapsulation:
The gate adopts high-quality rubber for the overall inner and outer rubber. European rubber vulcanization technology enables the vulcanized gate to ensure accurate geometric dimensions, and the rubber and ductile cast gate are firmly connected, not easy to fall off and have good elastic memory.

Precision casting valve body:
The valve body is made of precision casting, and the precise geometric dimensions make the inside of the valve body without any finishing to ensure the sealing of the valve.

Installation Precautions of gate valve:
1. Handwheels, handles and transmission mechanisms are not allowed to be used for lifting, and collisions are strictly prohibited.

2. The double gate valve should be installed vertically (that is, the valve stem is in the vertical position and the handwheel is on the top).

3. The gate valve with a bypass valve should be opened before opening (to balance the pressure difference between the inlet and outlet and reduce the opening force).

4. The gate valve with transmission mechanism should be installed according to the product manual.

5. If the valve is frequently opened and closed, lubricate at least once a month.

6. The gate valve is only used for the operation of the medium on various pipelines or equipment, which is fully open and fully closed, and is not allowed to be used for throttling.

7. For gate valves with hand wheels or handles, no auxiliary levers should be added during operation (if the sealing is not tight, the sealing surface or other parts should be checked and repaired). Turn the handwheel and handle clockwise to close, otherwise open. The gate valve with transmission mechanism should be used in accordance with the product manual.

Installation points of gate valve:

1) The installation position, height, and direction of inlet and outlet must meet the design requirements, and the connection should be firm and tight.

2) All kinds of manual valves installed on the thermal insulation pipeline must not handle downwards.

3) Visual inspection must be carried out before the valve is installed. The nameplate of the valve should comply with the current national standard “General Valve Marking” GB 12220. For valves with a working pressure greater than 1.0 MPa and a cut-off function on the main pipe, the strength and tightness performance test should be carried out before installation, and the valve can be used only after it is qualified. During the strength test, the test pressure is 1.5 times the nominal pressure, and the duration is not less than 5 min. The valve housing and packing should be qualified without leakage. During the tightness test, the test pressure is 1.1 times the nominal pressure; the test pressure should meet the requirements of the GB 50243 standard during the test duration, and no leakage on the valve flap sealing surface is qualified.

4) The hand wheel, handle and transmission mechanism are not allowed to be used for lifting, and collision is strictly prohibited.

5) The gate valve with transmission mechanism should be installed according to the product manual.

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

Classification and advantages of gate valve

August 13, 2020

Gate valve types:

There are many domestic manufacturers of gate valves, and most of the connection dimensions are not uniform.

gate valve (3)

Mainly divided into the following categories: 1. According to JB/T2203-1999 “Structural Length of Gate Valve”, the standard valve of the Ministry of Machinery; 2. According to GB/T12221-2005 “Metal Valve Structure Length”, the national standard valve; 3. According to American standard valves produced by ASME B16.10-2009 “Face-to-face and End-to-End Dimensions of Valves”.

Gate valves are divided into wedge type and parallel type according to the structure of the gate. There are 3 types of wedge gates: single gate, double gate and elastic gate.

Gate valves are divided into flat gate valves and knife gate valves according to their structure types.

The working principle of manual gate valve: Turn the hand wheel, and the valve plate connected with the valve stem can be lifted or lowered by the thread of the hand wheel and the valve stem to open and close.

According to the classification of shell/body material, gate valves can be divided into:

Metal material valves: such as carbon steel valves, alloy steel valves, stainless steel valves, cast iron valves, titanium alloy valves, Monel valves, copper alloy valves, lead alloy valves, etc.

Metal valve body lining valves: such as rubber-lined valves, fluorine-lined valves, lead-lined valves, plastic-lined valves, and enamel-lined valves.

Non-metallic materials valves: such as ceramic valves, glass valves, plastic valves.

Advantages of gate valve:
1. Small flow resistance. The medium channel inside the valve body is straight, the medium flows in a straight line, and the flow resistance is small.
2. Less effort when opening and closing. It is compared with the shut-off valve, because whether it is open or closed, the direction of movement of the gate is perpendicular to the direction of medium flow.
3. Large height and long opening and closing time. The opening and closing stroke of the gate is large, and the lifting is carried out by the screw.
4. Water hammer is not easy to produce. The reason is the long closing time.
5. The medium can flow in any direction on both sides, easy to install. Both sides of the gate valve channel are symmetrical.
6. The structural length (the distance between the two connecting end faces of the shell) is small.
7. Simple shape, short structure length, good manufacturing technology and wide application range.
8. Compact structure, good valve rigidity, smooth passage, small flow resistance, stainless steel and hard alloy sealing surface, long service life, PTFE packing, reliable sealing, light and flexible operation.

Disadvantages of gate valve:

It is easy to cause erosion and scratches between the sealing surfaces, and maintenance is difficult. The overall size is large, opening requires a certain amount of space, and the opening and closing time is long. The structure is more complicated.

Working principle and movement mode of gate valve

August 13, 2020

The gate valve is a gate for opening and closing. The movement direction of the gate is perpendicular to the direction

13 gate-valve-5

of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled. The gate valve is sealed through the contact between the valve seat and the gate plate. Usually, the sealing surface will be welded with metal materials to increase wear resistance, such as 1Cr13, STL6, stainless steel, etc. The gate has a rigid gate and an elastic gate. According to the difference of the gate, the gate valve is divided into a rigid gate valve and an elastic gate valve.

Working principle of gate valve:
The opening and closing part of the gate valve is a gate. The movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used model gate valve form a wedge. The wedge angle varies with valve parameters, usually 5°, and 2°52′ when the medium temperature is not high. The gate of the wedge gate valve can be made into a whole, called a rigid gate; it can also be made into a gate that can produce slight deformation to improve its manufacturability and compensate for the deviation of the sealing surface angle during the processing. The plate is called an elastic gate. When the gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, relying on the medium pressure to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves adopt forced sealing, that is, when the valve is closed, the gate must be forced against the seat by external force to ensure the sealing performance of the sealing surface. The gate valve of the gate valve moves linearly with the valve stem, which is called the lifting stem gate valve, also called the rising stem gate valve. Usually there is a trapezoidal thread on the lifting rod, through the nut on the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is turned into operating thrust. When the valve is opened, when the lift height of the gate is equal to 1:1 times the valve diameter, the fluid channel is completely unblocked, but this position cannot be monitored during operation. In actual use, the apex of the valve stem is used as the mark, that is, the position where it cannot be opened, as its fully open position. In order to take into account the locking phenomenon of temperature changes, it is usually opened to the top position, and then back 1/2-1 circle, as the position of the fully open valve. Therefore, the fully open position of the valve is determined by the position of the gate, that is, the stroke. In some gate valves, the stem nut is set on the gate, and the rotation of the handwheel drives the rotation of the valve stem to lift the gate. This kind of valve is called a rotating stem gate valve, or a dark stem gate valve.

Movement mode of gate valve:
When the gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, only rely on the medium pressure to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves adopt forced sealing, that is, when the valve is closed, the gate must be forced against the seat by external force to ensure the sealing performance of the sealing surface.

Movement mode: The gate of the gate valve moves linearly with the valve stem, which is also called the rising stem gate valve. Usually there is a trapezoidal thread on the lifting rod, through the nut on the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is changed into operating thrust. When the valve is opened, when the lift height of the gate is equal to 1:1 times the valve diameter, the fluid channel is completely unblocked, but this position cannot be monitored during operation. In actual use, the apex of the valve stem is used as the mark, that is, the position where it cannot be opened, as its fully open position. In order to take into account the locking phenomenon due to temperature changes, it is usually opened to the top position, and then rewind 1/2-1 turn, as the position of the fully open valve. Therefore, the fully open position of the valve is determined by the position of the gate (i.e. stroke). Some gate valve stem nuts are set on the gate, and the rotation of the handwheel drives the rotation of the valve stem to lift the gate. This kind of valve is called Rotating stem gate valve or dark stem gate valve.

The difference between globe valve and check valve

August 13, 2020

With the development of high-tech industry, various valves are often used in daily life. Today we will understand the difference between globe valves and check valves.

The difference between globe valve and check valve:
1. Check valve and stop valve are not the same thing, the difference between the two is mainly that the structure is

Globe valve (6)

very different.

2. The check valve is a one-way valve, which automatically prevents the fluid from flowing in the reverse direction, without a knob, and cannot artificially block the forward flow.

3. The stop valve has a knob, which can artificially control the forward flow. Due to its special structure, even if there is no artificial pipe valve, the fluid cannot flow in the reverse direction.

Globe valve:

The globe valve, also known as the shut-off valve, is a forced sealing valve, so when the valve is closed, pressure must be applied to the disc to force the sealing surface to not leak. When the medium enters the valve from below the valve

lift-swing-check-valve-2

disc, the resistance that the operating force needs to overcome is the friction force of the valve stem and the packing and the thrust generated by the pressure of the medium. The force of closing the valve is greater than the force of opening the valve, so the valve stem The diameter of the valve must be large, otherwise the valve stem will bend failure.
working principle of globe valve:
The globe valve, also called the cut-off valve, is one of the most widely used valves. The reason why it is so popular is that the friction between the sealing surfaces is small during the opening and closing process, which is relatively durable, has a low opening height, and is easy to manufacture. , Easy maintenance, not only suitable for medium and low pressure, but also suitable for high pressure. The closing principle of the globe valve is to rely on the pressure of the valve stem to make the sealing surface of the disc and the sealing surface of the valve seat tightly fit to prevent the medium from flowing. Our country’s valve “Sanhua” once stipulated that the flow direction of the stop valve should be from top to bottom, so there is directionality when installing. The structural length of the stop valve is longer than that of the gate valve, and the fluid resistance is large, and the sealing reliability is not strong during long-term operation.

Check valve:

Check valve refers to the valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent the medium from flowing back, also known as check valve, one-way valve, reverse flow valve, and back pressure valve. Check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and the discharge of the container medium.

working principle of check valve:
Check valve refers to the valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent the medium from flowing back. It is also called check valve, one-way valve, reverse flow valve and back pressure valve. Check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and the discharge of the container medium. The check valve can also be used to supply the auxiliary system whose pressure may rise above the system pressure. Check valves can be divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis).

Valve manufacturers recommend:
Tanghai Valve Factory is a technological enterprise that produces globe valves and check valves. It designs and produces according to your needs, and provides you with professional, high-quality, low-priced valve products. Welcome to call us for quotations.

Electric globe valves’ structural features and installation attention

August 12, 2020

Structural features of electric globe valve:

1. Open and close without friction. This function completely solves the problem of traditional valves affecting the

Globe valve (6)

sealing due to mutual friction between the sealing surfaces.

2. Top-mounted structure. The valves installed on the pipeline can be directly inspected and repaired online, which can effectively reduce device shutdown and reduce costs.

3. Single valve seat design. Eliminates the problem that the medium in the valve cavity affects the safety of use due to abnormal pressure increase.

4. Low torque design. The valve stem with special structure design can be opened and closed easily with only a small handle.

5. Wedge-shaped sealing structure. The valve relies on the mechanical force provided by the valve stem to press the ball wedge onto the valve seat to seal, so that the sealing performance of the valve is not affected by changes in pipeline pressure, and the sealing performance is reliably guaranteed under various working conditions.

6. Self-cleaning structure of the sealing surface. When the ball is tilted away from the valve seat, the fluid in the pipeline passes through the sealing surface of the ball evenly at 360°, which not only eliminates the local erosion of the valve seat by the high-speed fluid, but also washes away the accumulation on the sealing surface to achieve the purpose of self-cleaning .

7. The valve body and bonnet with valve diameter below DN50 are die forgings, and the valve body and bonnet above DN65 are steel castings.

8. The connection forms of the valve body and the bonnet are different, clamp pin shaft connection, flange gasket connection and self-sealing thread connection.

9. The sealing surfaces of the valve seat and the valve disc are all made of plasma spray welding or surfacing welding of cobalt-chromium-tungsten cemented carbide. The sealing surface has high hardness, wear resistance, scratch resistance and long service life.

10. The valve stem material is nitrided steel. After nitriding, the surface of the stem has high hardness, wear resistance, scratch resistance, corrosion resistance and long service life.

Electric shut-off valve installation attention:

1. Pay attention to the flow direction of the medium when installing the valve, and install it strictly in the direction indicated by the valve flow direction arrow.

2. The valve can be installed at any position of the pipeline, and at the same time, choose a carbon steel or alloy steel valve according to the temperature of the medium and the medium.

3. The electric globe valve should be installed vertically as far as possible, with the valve stem upward.

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

Characteristics and working principle of electric globe valve

August 12, 2020

Features of electric globe valve:

The fluid resistance is small, and its resistance coefficient is equal to that of a pipe section of the same length.
Globe valve (9)
Simple structure, small size and light weight. Electric globe valve
It is tight and reliable. The sealing surface material of the gate valve is widely used plastic, and it has good sealing performance. It has also been widely used in vacuum systems.
It is easy to operate and open and close quickly. It only needs to rotate 90° from fully open to fully closed, which is convenient for remote control.
The maintenance is convenient, the gate valve has a simple structure, the sealing ring is generally movable, and it is convenient to disassemble and replace.
When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium, and the medium will not cause erosion of the valve sealing surface when the medium passes.
It has a wide range of applications, with a diameter ranging from a few millimeters to a few meters, and can be applied from high vacuum to high pressure.

Electric globe valve classification:

According to its channel position, it can be divided into straight-through type and right-angle type.

Working principle of electric globe valve:

The working principle of the electric shut-off valve is to make the valve unblocked or blocked by rotating the valve. The gate valve switch is light, small in size, can be made into a large diameter, reliable in sealing, simple in structure, convenient in maintenance, the sealing surface and the spherical surface are often closed, and it is not easy to be eroded by the medium. It is widely used in various industries.

A. Opening process of globe check valve:

In the closed position, the valve body is pressed against the valve seat by the mechanical pressure of the valve stem.
When the hand wheel is turned counterclockwise, the valve stem moves in the opposite direction, and the angular plane at the bottom causes the ball to separate from the valve seat.
The valve stem continues to lift and interacts with the guide pin in the spiral groove of the valve stem, so that the ball begins to rotate without friction.
Until it reaches the fully open position, the valve stem is raised to the limit position, and the ball rotates to the fully open position.

B. Closing process of electric globe valve:

When closing, turn the handwheel clockwise, the valve stem begins to drop and the ball leaves the valve seat to start rotating.
Continue to rotate the hand wheel, and the valve stem will be acted on by the guide pin embedded in the upper spiral groove to make the valve stem and the gate rotate 90° at the same time.
When it is about to close, the gate body has rotated 90° without contact with the valve seat.
In the last few turns of the handwheel, the angular plane at the bottom of the valve stem mechanically wedges and presses the sphere to make it tightly press on the valve seat to achieve a complete seal.

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 of bellows globe valve and ordinary globe valve

August 12, 2020

Comparison of bellows globe valve and ordinary globe valve:

Globe valve (3)

1. Double sealing design (bellows + packing) If the bellows fails, the stem packing will also avoid leakage and meet international sealing standards.
2. There is no fluid loss, reducing energy loss and improving plant equipment safety.
3. Long service life, reduce maintenance times and lower operating costs.
4. The sturdy and durable bellows seal design ensures zero leakage of the valve stem and provides maintenance-free conditions.
5. The gas medium valve seat adopts PTFE soft sealing material to improve the sealing performance of this valve.
6. High temperature resistance≤425℃The valve seat adopts conical hard seal. Achieve airtight performance and zero leakage.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest globe valve manufacturers in China, main products are butterfly valves, check valves, gate valves and globe valves. Key words: 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…)

Our products use advanced manufacturing technology, and strictly conform to API, DIN, BS, EN, ISO, 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.

Characteristics of ball valve

What is a ball valve?

Knife gate valve introduction and its characteristics

Gate valve characteristics and installation notes

Classification and advantages of gate valve

Working principle and movement mode of gate valve

The difference between globe valve and check valve

Electric globe valves’ structural features and installation attention

Characteristics and working principle of electric globe valve

Comparison of bellows globe valve and ordinary globe valve

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