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Hard seal installation method of ball valve

August 14, 2020

Hard seal installation method of ball valve:

1) Remove the protective covers on both sides of the flange, and rinse and clean with the valve fully opened.

ball valve (6)

2) Before installation, the whole machine should be tested according to the specified signal (electrical or pneumatic) (to prevent vibration caused by transportation from affecting the performance), and then it can be installed online (wiring according to the electric actuator circuit diagram).
3) Before preparing to connect with the pipeline, flush and remove the remaining impurities in the pipeline (these substances may damage the valve seat and ball).
4) During installation, please do not use the actuator part of the valve as a lifting point to avoid damage to the actuator and accessories.
5) This type of valve should be installed in the horizontal or vertical direction of the pipeline.
6) The pipeline near the installation point should not be drooping or bear external force. Pipe supports or supports can be used to eliminate pipeline deviation.
7) After connecting with the pipeline, please cross-tighten the flange connecting bolts with the specified torque.

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…)

Installation instructions for ball valves

August 14, 2020

Installation instructions for ball valves:

1. Indoor devices or outdoor applications with protective methods;

ball valve (7)

2. Outdoor installations are corroded by wind, sand, rain, dew, and sunlight;
3. Have flammable, explosive gas or dust environment;
4. Humid tropical and dry tropical environment;
5. The temperature of the pipeline medium is as high as 450℃;
6. The ambient temperature is lower than -20℃;
7. Easy to be flooded or immersed in water;
8. Possess a radioactive material (nuclear power plant and radioactive material test device) environment;
9.The environment on the ship or dock (with salt spray, mold, humidity);
10.Occasions with severe vibration; occasions prone to fire;

For the electric ball valve in the above environment, the electric device structure, material and protection method are different. Therefore, the corresponding valve electric device should be selected according to the above-mentioned obligation environment. According to engineering control requirements, for electric ball valves, their control functions are completed by electric devices. The purpose of applying electric ball valves is to complete non-manual electrical control or computer control of valve opening, closing and adjustment linkage. The application of electric devices is not just for diligence and labor saving. Since the functions and quality of products from different manufacturers are quite different, the selection of electric devices and the selection of valves are equally important to the project. As the requirements of industrial automation level are constantly improving, on the one hand, the application of electric valves is increasing, and on the other hand, the control requirements for electric valves are getting higher and higher and more complicated. Therefore, the design of electric valves in electrical control is always updated. With the continuous improvement of use requirements and the popularization and application of computers, new and diverse electrical control methods will always appear. Regarding the overall control of the electric valve, attention should be paid to the selection of the control method of the electric valve. For example, depending on the needs of the project, whether to use a centralized control method or a single control method, whether to link with other equipment, sequence control or application computer sequence control, etc., the control principles are different. The sample of valve electric device manufacturers only gives standard electric control principles, so the application department should make technical clarifications with the electric device consumer to understand the technical requirements.

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

The parameter and troubleshooting of the ball valve

August 14, 2020

The parameter level of the ball valve:

1. Nominal pressure or pressure level: PN1.0-32.0MPa, ANSI CLASS 150-900, JIS10-20K;

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2. Nominal diameter or caliber: DN6～900, NPS 1/4 ～36;

3. Connection method: flange, butt welding, thread, socket welding, etc.;

4. Applicable temperature: -196℃～540℃;

5. Drive mode: manual, worm gear drive, pneumatic, electric, hydraulic, gas-liquid linkage, electro-hydraulic linkage;

6. Valve body material: WCB, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, CF8 (304), CF3 (304L), CF8M (316), CF3M (316L), Ti. Different materials are used, which can be applied to various media such as water, steam, oil, nitric acid, acetic acid, oxidizing medium, urea, etc.

Pressure limit of ball valve:
The nameplate shows the maximum allowable operating pressure of the ball valve at the maximum and minimum operating temperatures.

Seats and seals made of PTFE or RTFE are used. The operating temperature of other types of seat and seals should be checked by the KI factory.

The nominal pressure rating (PN) of the valve can indicate the maximum working pressure of the valve under normal temperature conditions. (For example: PN4.0, indicating that the maximum working pressure is 40 Bar (4.0MPa) when the operating temperature is between -190C and 380C).

For the precautions of electric or pneumatic actuators, refer to their corresponding instructions.

Troubleshooting of the ball valve:
The ball valve has been scoured by the material for a long time, causing friction, causing severe impact and abrasion, which cannot meet the normal production, and at the same time, the equipment life is shortened. At present, wear-resistant materials, such as ceramic materials and polymer composite materials, are mostly used for the wear of ball valves, and there are more technical systems used. The polymer material has superior adhesion performance, super wear resistance, and safely solves the disadvantages of frequent metal wear and ensures the normal production of enterprise equipment. Moreover, the unique ceramic material and special surface strengthening agent in the material make it better than any steel or even ceramic tile in wear resistance and physical impact resistance in the harshest dry grinding environment. The incompatibility of the product with coal is to prevent Ideal material for coal deposits.

Product features and advantages of ball valve

August 14, 2020

Product features of ball valve:
1. The three-way ball valve adopts an integrated structure in structure, with a four-sided valve seat sealing type, fewer flange connections, high reliability, and a lightweight design.

ball valve (8)

2. The three-way ball core is divided into T type and L type, with long service life, large circulation capacity and low resistance.

3. The ball valve is divided into two types: single-acting and double-acting according to the action type. The single-acting type is characterized in that once the power source fails, the ball valve will be in the state required by the control system.

Advantages of ball valve:

1. The fluid resistance is small, and its resistance coefficient is equal to that of a pipe section of the same length.

2. Simple structure, small size and light weight.

3. It is tight and reliable, and the sealing surface material of the ball valve is widely used in plastics and has good sealing performance. It has also been widely used in vacuum systems.

4. 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.

5. The maintenance is convenient, the structure of the ball valve is simple, the sealing ring is generally movable, and it is convenient to disassemble and replace.

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

This type of valve is a high-pressure ball valve commonly used in existing mines. It bears high pressure and adopts a U-shaped card quick connection method. It can be quickly installed and disassembled in the daily production and use of the mine, and is convenient to use.

The ash unloading ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. The ash unloading ball valve can be divided into floating ball type, fixed ball type, and elastic ball type. The ash unloading ball valve is mainly used to cut off or connect the medium in the pipeline. It can also be used for fluid adjustment and control. The ash unloading ball valve Compared with other valve types, it has angular stroke output torque, opens quickly, is stable and reliable, and is widely applicable. The working principle of the ash unloading ball valve is to make the valve unblocked or blocked by rotating the valve.

Electric ball valve structure is composed of only a few parts, saving data; small size, light weight, small installation size, electric ball valve structure diagram, small driving torque, pressure regulating valve, easy and agile operation, only need to rotate 90° Fast opening and closing; and also has a good flow regulation effect and sealing characteristics at the same time, in the application of large and medium caliber, medium and low pressure, electric ball valve is the dominant valve form. When the electric ball valve is in the fully open position, the thickness of the butterfly plate is the resistance when the medium flows through the valve body, so the pressure drop that occurs through the valve is small, so it has better flow control characteristics. Electric ball valves have two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate. Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the disadvantage of being limited by temperature. If the electric ball valve is requested to be used as a flow control, it is important to accurately select the size and type of the valve. The construction principle of the electric ball valve is particularly suitable for manufacturing large diameter valves. Electric ball valves are not only widely used in general industries such as petroleum, gas, chemical, and water disposal, but also used in cooling water systems of thermal power stations. Commonly used electric ball valves include wafer type electric ball valves and flange type electric ball valves. Wafer type electric ball valve uses double-head bolts to connect the valve between two pipe flanges. Flange type electric ball valve is equipped with flanges on the valve. The two flanges on the valve are connected to the pipe flanges with bolts. The strength performance of the valve refers to the ability of the valve to withstand medium pressure. The valve is a mechanical product that is subjected to internal pressure, so it must have sufficient strength and rigidity to ensure long-term use without cracking or deformation. Pneumatic ball valve is composed of ball valve and pneumatic actuator. Pneumatic actuator is divided into double-acting pneumatic actuator and single-acting pneumatic actuator. Through solenoid valve control, ball valve switching action is realized. The pneumatic ball valve can realize intelligent control, quickly open or close the pipeline, and can effectively control and manage the pipe network.

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 characteristics of ball valve

August 14, 2020

There are different ways of classification of ball valves.

Function classification:
1. Bypass valve: The ball valve is generally opened by static water, so the bypass valve is set to be pressed first, that is, both sides are filled with water;

ball valve (6)

2. Air valve: when filling with water, the buoy will automatically close the valve when the air is removed; when draining, the buoy will drop by itself when it is used for replenishing air;

3. Pressure relief valve: When opening and closing the valve, remove the pressure water between the valve and the sealing cover to avoid wearing the sealing cover;

4. Drain valve: drain the sewage in the lower part of the ball shell.

Transmission classification:
1. Pneumatic ball valve

2. Electric ball valve

3. Hydraulic ball valve

4. Pneumatic hydraulic ball valve

5. Electro-hydraulic ball valve

6. Turbine drive ball valve

Classification characteristics of ball valve:

Ball valves are divided into: floating ball valve, fixed ball valve, orbital ball valve, V-shaped ball valve, three-way ball valve, stainless steel ball valve, cast steel ball valve, forged steel ball valve, ash unloading ball valve, anti-sulfur ball valve, pneumatic ball valve, electric ball valve, card sleeve Ball valves, welded ball valves.

Classified by shell/body material, ball valves can be divided into:

1. 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, aluminum alloy valves, lead alloy valves, etc.

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

3. Valves of non-metallic materials: such as ceramic valves, glass valves, and plastic valves.

There are many domestic manufacturers of ball valves, and most of the connection sizes are not uniform. Mainly divided into the following categories:

The ball of the ball valve is floating. Under the action of the medium pressure, the ball can produce a certain displacement and press tightly on the sealing surface of the outlet end to ensure that the outlet end is sealed.

Structural features of ball valve:
The sealing performance is good, but all the load of the sphere bearing the working medium is transmitted to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the sphere medium. When subjected to higher pressure impact, the sphere may deviate . This structure is generally used for medium and low pressure ball valves.

The ball of the ball valve is fixed and does not move when pressed. The fixed ball valve is equipped with a floating valve seat. After receiving the pressure of the medium, the valve seat will move, so that the sealing ring is pressed tightly on the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts of the ball, and the operating torque is small, which is suitable for high pressure and large diameter valves.

In order to reduce the operating torque of the ball valve and increase the reliability of the seal, an oil-sealed ball valve has appeared, which not only injects a special lubricant between the sealing surfaces to form a layer of oil film, which enhances the sealing performance and reduces the operating torque. Suitable for high pressure and large diameter ball valves.

Flexible features of ball valve:

The ball of the ball valve is elastic. Both the ball and the valve seat sealing ring are made of metal materials, and the sealing specific pressure is very large. The pressure of the medium itself cannot meet the sealing requirements, and external force must be applied. This valve is suitable for high temperature and high pressure media.

The elastic sphere is made by opening an elastic groove on the lower end of the inner wall of the sphere to obtain elasticity. When closing the passage, use the wedge-shaped head of the valve stem to expand the ball and press the valve seat to seal. Loosen the wedge-shaped head before rotating the sphere, and the sphere will return to its original shape, so that there is a small gap between the sphere and the valve seat, which can reduce the friction and operating torque of the sealing surface.

Qv347, Qv647, Qv947 V-type regulating ball valve

The Qv347, Qv647, and Qv947 V-type regulating ball valves have a shearing effect on the valve seat because the ball core has a V-shaped structure. Therefore, it is suitable for the control of relevant process parameters in the suspension medium containing fibers or small solid particles in papermaking, chemical, metallurgical and other industrial enterprises. It is especially suitable for the pulp, white water, black liquor and white water in the pulp and paper production process. Automatic adjustment of the fluid of suspended particles such as liquid and thick and turbid slurry fluid medium.

This V-shaped ball valve is a fixed ball valve and also a single-seat sealed ball valve. The adjustment performance is the best among ball valves, the flow characteristics are equal percentages, and the adjustable ratio is 100:1. It has a shearing effect between the V-shaped incision and the metal valve seat, which is especially suitable for media containing fibers, small solid particles, slurry, etc.

Three-way ball valve has T type and L type. The T type can connect three orthogonal pipelines with each other and cut off the third channel, which can split and merge. The L-shape can only connect two orthogonal pipelines, and cannot maintain the third pipeline to communicate with each other at the same time. It only plays a role of distribution.

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.

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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

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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.

Hard seal installation method of ball valve

Installation instructions for ball valves

The parameter and troubleshooting of the ball valve

Product features and advantages of ball valve

Classification and characteristics of ball valve

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

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