Our goal: to be a high-quality manufacturer of industrial control valves, gaining unanimous recognition from new and old customers
Our mission: To fully utilize the effectiveness of industrial control valves to achieve better results
Ball valve is defined in the standard GB/T21465-2008 "Valve Terminology" as a valve in which the opening and closing member (ball) is driven by the valve stem and rotates around the axis of the valve stem. It is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid regulation and control. Among them, the hard sealed V-shaped ball valve has a strong shear force between its V-shaped ball core and the metal valve seat welded with hard alloy, especially suitable for media containing fibers and small solid particles. The multi way ball valve can not only flexibly control the confluence, diversion, and flow direction switching of media on the pipeline, but also close any channel and connect the other two channels. This type of valve should generally be installed horizontally in the pipeline. Ball valve classification: pneumatic ball valve, electric ball valve, manual ball valve.
development
Ball valve was introduced in the 1950s. With the rapid development of science and technology, and the continuous improvement of production process and product structure, it has rapidly developed into a major valve category in a short period of 40 years. In Western industrialized countries, the use of ball valves is increasing year by year. In China, ball valves are widely used in petroleum refining, long-distance pipelines, chemicals, paper making, pharmaceuticals, water conservancy, electricity, municipal, steel, and other industries, occupying a pivotal position in the national economy.
effect
It has a 90 degree rotation action, and the plug body is a sphere with a circular through-hole or passage through its axis. Ball valves are mainly used in pipelines to cut off, distribute, and change the flow direction of media. They can be tightly closed with only 90 degrees of rotation and a small rotational torque. Ball valves are suitable for use as switch and shut-off valves, and V-shaped ball valves.
Comprehensive introduction
In addition to paying attention to pipeline parameters, electric valves should also pay special attention to the environmental conditions of their obligations. As the electric device in electric valves is an electromechanical device, its obligation status is greatly affected by its obligation environment.
In general, special attention should be paid to the use of electric ball valves and butterfly valves in the following environments.
Hard seal
characteristic
1; wear-resisting; Due to the fact that the valve core of the hard sealed ball valve is alloy steel spray welded, and the sealing ring is alloy steel overlay welded, the hard sealed ball valve will not generate too much wear during opening and closing. (Its hardness coefficient is 65-70):
2; Good sealing performance; As the sealing of hard sealed ball valves is manual grinding, they cannot be used until the valve core and sealing ring completely match. Therefore, its sealing performance is reliable.
3; Light switch; As the bottom of the sealing ring of a hard sealed ball valve uses a spring to tightly hold the sealing ring and valve core together, the switch is very light when external forces exceed the preload of the spring.
4; With a long service life, it has been widely used in various departments such as petroleum, chemical industry, power generation, paper making, atomic energy, aviation, rockets, and people's daily lives.
Pneumatic ball valves have a compact structure, reliable sealing, simple structure, and convenient maintenance. The sealing surface and spherical surface are often in a closed state, and are not easily eroded by media. They are easy to operate and maintain. They are suitable for general working media such as water, solvent, acid, and natural gas. They are mainly used to cut off or connect media in pipelines, and can also be used for fluid regulation and control. Compared to other valve types, pneumatic ball valves have angular stroke output torque, rapid opening Stable and reliable, widely applicable, and other advantages. 1. The thrust bearing reduces the friction torque of the valve rod, which can make the long-term operation of the valve rod stable and flexible. 2. Anti static function: A spring is installed between the ball, valve rod, and valve body, which can export the static electricity generated during the switching process. 3. Due to the good self-lubrication of materials such as polytetrafluoroethylene and low friction loss with the ball, the service life of pneumatic ball valves is long. 4. "Low fluid resistance, pneumatic ball valves are one of the categories of all valves with low fluid resistance, even for reduced diameter pneumatic ball valves, their fluid resistance is relatively small.". 5. The sealing of the valve rod is reliable. As the valve rod only rotates without lifting, the packing seal of the valve rod is not easily damaged, and the sealing ability increases with the increase of medium pressure. 6. The valve seat has good sealing performance. The sealing ring made of elastic materials such as polytetrafluoroethylene is easy to seal in structure, and the sealing ability of pneumatic ball valves increases with the increase of medium pressure.
advantage
1. Low fluid resistance, with almost no flow resistance for full bore ball valves.
2. Simple structure, small size, and light weight.
3. Tight and reliable. It has two sealing surfaces, and the sealing surface material of the ball valve is widely used in various plastics, which has good sealing performance and can achieve complete sealing. It has also been widely used in vacuum systems.
4. Convenient operation, quick opening and closing, with only 90 ° rotation from full opening to full closing, facilitating remote control.
5. Convenient maintenance, simple ball valve structure, generally movable sealing rings, and convenient disassembly and replacement.
6. When fully open or fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium, and when the medium passes through, it will not cause erosion of the valve sealing surface.
7. Wide range of applications, ranging from small to a few millimeters in diameter to several meters in diameter, from high vacuum to high pressure applications.
Due to the wiping property of ball valves during opening and closing, they can be used in media with suspended solid particles.
High machining accuracy, high cost, and difficult to use in high temperatures. If there are impurities in the pipeline, it is easy to be blocked by impurities, resulting in the valve being unable to open.
development
China has a large valve industry chain, but it is not a valve power. Overall, China has entered the ranks of the world's leading valve countries, but from the perspective of product quality, there is still a long gap between China and a powerful valve country. The low concentration of production in the industry, the low research and development capacity of valves matching high-end products, and the low level of manufacturing technology in the valve industry still exist, and the import and export trade deficit continues to expand.
The next few years will be a period of high-speed shocks in the valve industry, and the direct consequence of this high-speed shock is the expansion of the polarization trend in the valve cabinet brand camp. It is expected that there will definitely not be so many valve enterprises that can truly survive in the market in the next few years. However, this high-speed fluctuation in the valve industry will bring enormous opportunities, and the result of the fluctuation will make the market operation more rational.
The road to localization of high-end valves is unusually bumpy. Basic components have become a bottleneck restricting the high-end development of China's manufacturing industry. During the 12th Five Year Plan period, the government will continue to strengthen the localization of high-end equipment components. Here, we select representative valves from several key development industries mentioned in the Implementation Plan for feasibility analysis of import substitution. From the analysis, we can see that the feasibility of valve import substitution varies greatly among various sub industries, and high-end valves require more policy guidance and scientific research support.
The valve industry plays a very important role in the development of the national economy as an important link in preparing for manufacturing. Due to the gap between China's domestic valve manufacturing industry and the international level, many key valves with high parameters, high temperature and pressure, and high weight have always relied on imports. In order to promote the localization of valves, after the "Opinions on Accelerating the Revitalization of the Equipment Manufacturing Industry" issued by the State Council, the relevant national departments have made a series of major deployments in accordance with the national requirements for the localization of major equipment, Led by the National Development and Reform Commission, the China Machinery Industry Federation and the China General Machinery Industry Association have jointly deployed and formulated valve localization plans for major equipment in relevant fields, and have coordinated with relevant departments for many times. Now, there is a consensus on valve localization in the domestic valve industry.
Actively adopt international standards for product design; Absorb foreign design structures; Product testing and performance inspection shall be conducted in strict accordance with international standards; Absorb foreign production process experience and attach importance to the research, promotion and application of new materials; Understanding the technical parameters and operating conditions of imported high parameter valve products is a way to accelerate the localization process, promote the continuous updating of valve products, and comprehensively realize the localization of valves.
With the acceleration of the pace of restructuring in the valve industry, the future industry will be a competition between the quality and safety of valve products and product brands. Products will develop towards high technology, high parameters, strong corrosion resistance, and long service life. Only through continuous technological innovation, development of new products, and technical transformation can we gradually improve the technical level of products, meet domestic device requirements, and fully realize the localization of valves. Under the huge demand environment, the valve manufacturing industry in China will definitely present a better development prospect. The main feature of ball valves is their compact structure, which is suitable for general working media such as water, solvents, acids, and natural gas, as well as for media with poor working conditions, such as oxygen, hydrogen peroxide, methane, and ethylene. They are widely used in various industries. The valve body of a ball valve can be integral or combined.
Ball valve not only has simple structure and good sealing performance, but also has small volume, light weight, low material consumption, small installation size, small driving torque, simple operation, and easy to achieve rapid opening and closing within a certain nominal diameter range. It is one of the fastest growing valve varieties in the past decade. The ball valve is evolved from the plug valve, and its opening and closing parts act as a ball, using the ball to rotate 90 ° around the axis of the valve stem to achieve the purpose of opening and closing. Ball valves are mainly used in pipelines to cut off, distribute, and change the flow direction of media. Ball valves designed with V-shaped openings also have good flow regulation functions.
Especially in industrialized countries such as the United States, Japan, Germany, France, Italy, the West, and the United Kingdom, ball valves are widely used, and the variety and quantity of ball valves are still expanding. They are developing towards high temperature, high pressure, large diameter, high sealing performance, long life, excellent regulatory performance, and one valve multi-function. Their reliability and other performance indicators have reached a high level, and have partially replaced gate, globe, and throttle valves. With the technological progress of ball valves, they will have a wider application in the foreseeable short term, especially in oil and gas pipelines, oil refining and cracking devices, and the nuclear industry. In addition, in other industries, ball valves will also become one of the leading valve types in large and medium-sized caliber, medium and low pressure fields.
classification
By Function
1. Bypass valve: Generally, the ball valve is opened in still water, so the bypass valve should be set for flat pressure first, that is, both sides should be filled with water;
2. Air valve: When filling water, discharge air and use the float to close the valve automatically; When draining water, it is used to replenish air, and the float descends automatically;
3. Pressure relief valve: When opening and closing the valve, drain the pressure water between the valve and the sealing cap to avoid wearing the sealing cap;
4. Blowdown valve: discharge the sewage from the lower part of the spherical shell.
Press the transmission mechanism
1. Pneumatic ball valve
2. Electric ball valve
3. Hydraulic ball valve
4. Pneumatic ball valve
5. Electro hydraulic ball valve
6. Turbine drive ball valve
Maintenance matters
Ten Precautions
(1) It is necessary to verify that the upstream and downstream pipes of the ball valve have been depressurized before disassembly and disassembly operations can be carried out.
(2) After cleaning, non-metallic parts should be taken out of the cleaning agent immediately and should not be soaked for a long time.
(3) During assembly, the bolts on the flange must be tightened symmetrically, gradually, and evenly.
(4) The cleaning agent should be compatible with the rubber parts, plastic parts, metal parts, and working media (such as gas) in the ball valve. When the working medium is gas, gasoline (GB484-89) can be used to clean metal parts. Clean non-metallic parts with pure water or alcohol.
(5) Each disassembled ball valve part can be cleaned by immersion washing. Metallic parts that still have non metallic parts that have not been disassembled can be scrubbed using a clean, fine and clean silk cloth impregnated with cleaning agent (to avoid fiber peeling and adhesion to the parts). During cleaning, all grease, dirt, adhesive deposits, dust, etc. that adhere to the wall surface must be removed.
(6) When disassembling and reassembling ball valves, care must be taken to prevent damage to the sealing surfaces of parts, especially non-metallic parts. Special tools should be used when taking out O-rings.
(7) After cleaning, it is necessary to wait for the volatilization of the cleaning agent on the cleaned wall surface (it can be wiped with a silk cloth that is not soaked in the cleaning agent) for assembly, but it must not be left for a long time, otherwise it will rust and be contaminated by dust.
(8) New parts also need to be cleaned before assembly.
(9) Lubricate with grease. The lubricating grease shall be compatible with the metal materials, rubber parts, plastic parts, and working media of the ball valve. When the working medium is gas, such as Te 221 grease can be used. Apply a thin layer of grease to the surface of the seal mounting groove, a thin layer of grease to the rubber seal, and a thin layer of grease to the sealing and friction surfaces of the valve stem.
(10) During assembly, metal debris, fibers, grease (except those specified for use), dust, other impurities, foreign matters, etc. shall not be allowed to contaminate, adhere to, stay on the surface of the part or enter the inner cavity.
Classification characteristics
Ball valves include: floating ball valve, fixed ball valve, rail ball valve, V-shaped ball valve, three-way ball valve, stainless steel ball valve, forged steel ball valve, ash discharge ball valve, sulfur resistant ball valve, pneumatic ball valve, electric ball valve, ferrule ball valve, and welding ball valve.
According to the classification of housing/main body materials, ball 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, aluminum alloy valves, lead alloy valves, etc.
Metal valve body lined valves: such as rubber lined valves, fluorine lined valves, lead lined valves, plastic lined valves, and enamel lined valves.
3. Valves made of non-metallic materials: such as ceramic valves, glass valves, and plastic valves.
The ball of a ball valve is floating, and under the action of medium pressure, the ball can produce a certain displacement and tightly press on the sealing surface at the outlet end, ensuring the sealing at the outlet end.
structure
Floating ball valves have good sealing performance, but the ball bears the load of the working medium and all of it is transferred to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. When subjected to high pressure impact, the ball may deflect. This structure is generally used for medium and low pressure ball valves.
The ball of a ball valve is fixed and does not move under pressure. Fixed ball valves are equipped with floating valve seats. When subjected to medium pressure, the valve seats move, causing the sealing ring to press tightly against the ball to ensure sealing. Generally, bearings are installed on the upper and lower shafts of the ball, with small operating torque, and are suitable for high-pressure and large-diameter valves.
In order to reduce the operating torque of ball valves and increase the reliability of sealing, an oil sealed ball valve has emerged, which not only injects special lubricating oil between the sealing surfaces to form an oil film, which enhances the sealing performance, but also reduces the operating torque, making it more suitable for high-pressure large-diameter ball valves.
elastic
The ball of a ball valve is elastic. The ball and valve seat sealing rings are made of metal materials, with a high sealing pressure ratio. The pressure of the medium itself cannot meet the sealing requirements, and external forces must be applied. This valve is suitable for high-temperature and high-pressure media.
An elastic sphere is formed by opening an elastic groove at the lower end of the inner wall of the sphere to obtain elasticity. When closing the channel, use the wedge head of the valve rod to expand the ball and press the valve seat tightly to achieve a seal. Before rotating the ball, loosen the wedge head, and the ball will then return to its original shape, creating a small gap between the ball and the valve seat, which can reduce friction and operating torque on the sealing surface.
Qv347, Qv647, Qv947 V-shaped Regulating Ball Valve
Qv347, Qv647, and Qv947 V-shaped regulating ball valves have a V-shaped structure with a ball core, which has a shearing effect on the valve seat. Therefore, it is applicable to the control of relevant process parameters in suspended liquid media containing fibers or small solid particles in industrial enterprises such as papermaking, chemical engineering, metallurgy, etc., and is particularly suitable for the automatic regulation of suspended particle fluids such as pulp, white water, black liquor, white liquor, and thick and turbid slurry fluid media in the pulping and papermaking production processes.
This V-shaped ball valve is a fixed ball valve and also a single seat sealed ball valve. Its regulating performance is among the ball valves, and its flow characteristics are equal in percentage, with an adjustable ratio of 100:1. Its V-shaped notch has a shearing effect between the metal valve seat and is particularly suitable for media containing fibers, small solid particles, slurry, and other media.
Three way ball valves are available in T and L shapes. The T-shape can connect three orthogonal pipes to each other and cut off the third channel, playing a role of diversion and confluence. The L-shape can only connect two pipes that are orthogonal to each other, and cannot simultaneously maintain the connectivity of the third pipe. It only serves as a distribution function.
Product Features
1. The three-way ball valve adopts an integrated structure and a sealing type of 4-sided valve seat, with fewer flange connections and high reliability. The design achieves lightweight.
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. Ball valves are divided into single acting and double acting types. The characteristic of the single acting type is that in the event of a power source failure, the ball valve will be in the state required by the control system.
advantage:
1. The fluid resistance is small, and its resistance coefficient is equal to that of pipe sections of the same length.
2. Simple structure, small size, and light weight.
3. Tight and reliable, the sealing surface material of ball valve is widely used in plastic, with good sealing performance, and has also been widely used in vacuum systems.
4. Convenient operation, quick opening and closing, with only 90 ° rotation from full opening to full closing, facilitating remote control.
5. Convenient maintenance, simple ball valve structure, generally movable sealing rings, and convenient disassembly and replacement.
6. Wide application range, with diameters ranging from a few millimeters to several meters. It can be applied under high vacuum or high pressure.
This type of valve is a commonly used high-pressure ball valve in existing mines. It bears high pressure and adopts a U-shaped card quick connect method. It can be quickly installed and disassembled in daily production and use in mines, making it easy to use.
The ash discharge ball valve is mainly used to cut off, distribute, and change the flow direction of the medium in the pipeline. The ash discharge ball valve can be divided into floating ball type, fixed ball type, and elastic ball type according to its structure. The ash discharge ball valve is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid regulation and control. Compared with other valve types, the ash discharge ball valve has angular stroke output torque, rapid opening, stability, and reliability, and is widely applicable. The working principle of the ash discharge ball valve is to rotate the valve to make the valve unblocked or blocked.
The electric ball valve structure consists of only a few parts, saving data consumption; Small size, light weight, small installation size, electric ball valve structure diagram, small driving torque, pressure regulating valve, simple and agile operation, only need to rotate 90 ° to quickly open and close; Moreover, it also has good flow regulation efficiency and sealing characteristics. In the application field of large, medium, and low pressure, electric ball valves are the dominant valve situation. When the electric ball valve is in the fully open position, the thickness of the butterfly plate is the resistance of the medium flowing through the valve body, so the pressure drop through the valve is very small, so it has good 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 service 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 electric ball valves are requested for flow control, it is important to accurately select the size and type of valve. The construction principle of electric ball valves is particularly suitable for manufacturing large diameter valves. Electric ball valves are not only widely used in general industries such as petroleum, gas, chemicals, and water treatment, but also used in cooling water systems in thermal power plants. Commonly used electric ball valves include wafer type electric ball valves and flange type electric ball valves. "Wafer type electric ball valves connect the valve between two pipe flanges with studs. Flange type electric ball valves have flanges on the valve, and bolts are used to connect the flanges on both ends of the valve to the pipe flange.". The strength performance of a valve refers to its ability to withstand medium pressure. Valves are mechanical products subject to internal pressure, so they must have sufficient strength and stiffness to ensure long-term use without cracking or deformation. The pneumatic ball valve consists of a ball valve equipped with a pneumatic actuator. The pneumatic actuator is divided into a double acting pneumatic actuator and a single acting pneumatic actuator. It is controlled by a solenoid valve to achieve the switching action of the ball valve. Pneumatic ball valve can realize intelligent control, quickly open or close pipelines, and effectively control and manage the pipeline network.
repair
Having a long service life and maintenance free period will depend on the following factors: normal working conditions, maintaining a harmonious temperature/pressure ratio, and reasonable corrosion data
● When the ball valve is closed, there is still pressurized fluid inside the valve body
● Before maintenance, relieve the pipeline pressure and place the valve in the open position
● Disconnect the power or air source before maintenance
● Disconnect the actuator from the bracket before maintenance
● Before disassembly and disassembly, it is necessary to verify that the upstream and downstream pipes of the ball valve have been depressurized
During disassembly and reassembly, care must be taken to prevent damage to the sealing surface of parts, especially non-metallic parts. Special tools should be used when taking out O-rings
During assembly, the bolts on the flange must be tightened symmetrically, gradually, and evenly
● The cleaning agent should be compatible with rubber parts, plastic parts, metal parts, and working media (such as gas) in the ball valve. When the working medium is gas, gasoline (GB484-89) can be used to clean metal parts. Clean non-metallic parts with purified water or alcohol
● After cleaning, non-metallic parts should be taken out of the cleaning agent immediately and should not be soaked for a long time
After cleaning, it is necessary to wait for the volatilization of the cleaning agent on the cleaned wall surface (it can be wiped with a silk cloth that is not soaked in the cleaning agent) for assembly, but it must not be left for a long time, otherwise it will rust and be contaminated by dust
● New parts also need to be cleaned before assembly
● During assembly, it is not allowed to have metal debris, fibers, grease (except for those specified for use), dust, other impurities, foreign matters, etc. contaminate, adhere to or stay on the surface of the parts or enter the inner cavity. If there is slight leakage at the filler, the valve rod nut must be locked again.
Note: Do not lock it too tightly. Usually, lock it for another 1/4 to 1 turn, and the leakage will stop.
A) Disassembly
Place the valve in the half open position to flush and remove potentially hazardous substances inside and outside the valve body.
Close the ball valve, remove the connecting bolts and nuts on both flanges, and then completely remove the valve from the pipeline.
Disassemble the drive unit in sequence - actuator, connecting bracket, lock washer, valve stem nut, butterfly spring piece, Glenn, wear plate, and valve stem packing.
Remove the body cover connecting bolts and nuts, separate the valve cover from the valve body, and remove the valve cover gasket.
Confirm that the valve ball is in the "off" position, which can easily be taken out of the valve body, and then take out the valve seat.
Gently push the valve rod downward through the middle hole of the valve body until it is completely removed, and then take out the O-ring and the lower packing of the valve rod.
Note: Please operate carefully to avoid scratching the valve stem surface and the sealing part of the valve body stuffing box.
B) Reassembly
Clean and inspect the removed parts, and it is strongly recommended to replace the valve seat, bonnet gasket, and other seals with a spare parts kit.
Assemble in the reverse order of disassembly.
Tighten the flange connecting bolts crosswise with the specified torque.
Tighten the valve stem nut with the specified torque.
After installing the actuator, input the corresponding signal to drive the valve core to rotate through the rotating valve rod, making the valve open and closed.
If possible, please conduct a pressure seal test and performance test on the valve according to relevant standards before reinstalling the pipeline.
1. Principle
The opening and closing member of a ball valve is a ball that rotates around the center line of the valve body to achieve opening and closing.
2. Applicable place
Places on low pressure and small diameter pipelines that are used to cut off water flow and change the distribution of water flow or require rapid opening and closing.
3. Features
1) Low flow resistance;
2) Simple structure;
3) Small size and light weight;
4) The sealing surface material of the ball valve is plastic, with good sealing performance;
5) Easy to operate, fast to open and close, and convenient for remote control;
6) Convenient maintenance, sealing rings are generally movable, and easy to disassemble and replace;
7) When fully open or fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium, and the passage of the medium will not cause erosion of the valve sealing surface.
4. Classification
1) According to their working principles, commonly used ball valves are divided into floating ball valves, fixed ball valves, and lift rod ball valves.
2) Ball valves can be divided into straight-through, three-way, and right-angle types according to their channel positions. The latter two ball valves are used to distribute media and change the flow direction of the media.
5. Key points of construction and installation
1) The installation position, height, inlet and outlet directions must meet the design requirements, and the connection should be firm and tight.
2) The handle of various manual valves installed on insulated pipes shall not be downward.
3) Visual inspection must be conducted before valve installation. The nameplate of the valve should comply with the current national standard "General Purpose Valve Signs" GB 12220. For valves with a working pressure greater than 1.0 MPa and having a cutoff effect on the main pipe, strength and tightness tests should be conducted before installation, and they can only be used after passing the tests. During the strength test, the test pressure shall be 1.5 times the nominal pressure, and the duration shall not be less than 5min. The valve shell and filler shall be free of leakage, which is considered qualified. During the tightness test, the test pressure shall be 1.1 times the nominal pressure; The test pressure during the duration of the test shall comply with the requirements of GB 50243 standard, and the valve flap sealing surface shall be qualified if there is no leakage.
4) Install sealing gasket between valve flange and pipeline flange according to pipeline design requirements.
5) The ball valve with transmission mechanism shall be installed according to the product instructions.
6. Executive standards
1) Product standards
General Purpose Valves - Flanged and Butt Welded Steel Ball Valves (GB/T12237-89)
"Iron and Copper Ball Valves" GB/T 15185-1994
General Requirements for Steel Valves (GB/T 12224-2005)
Standard for Safety Evaluation of Equipment and Protective Materials for Drinking Water Transmission and Distribution (GB/T 17219-1998)
2) Engineering standards
Code for Acceptance of Construction Quality of Building Water Supply, Drainage, and Heating Engineering (GB 50242-2002)
Code for Acceptance of Construction Quality of Ventilation and Air Conditioning Engineering (GB 50243-2002)
Parameter level
1. Nominal pressure or pressure level: PN1.0-32.0MPa, ANSI CLASS 150-900, JIS10-20K;
2. Nominal diameter or diameter: 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 and worm drive, pneumatic, electric, hydraulic, pneumatic-hydraulic, and electro-hydraulic linkage;
6. Valve body materials: WCB, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, CF8 (304), CF3 (304L), CF8M (316), CF3M (316L), Ti. Different materials can be used for various media such as water, steam, oil, nitric acid, acetic acid, oxidizing media, urea, etc.
Pressure limit
The nameplate shows the allowable high operating pressure of the ball valve at both high and low operating temperatures.
The operating temperature of valve seats and seals made of PTFE or RTFE, and other types of valve seats and seals, should be subject to inspection by the KI factory.
The nominal pressure rating (PN) of the valve can indicate the high working pressure of the valve under normal temperature conditions. (For example, PN4.0 indicates a large working pressure of 40 Bar (4.0 MPa) when the operating temperature is between - 190C and 380C).
For precautions for electric or pneumatic actuators, refer to their corresponding instructions.
Troubleshooting
Ball valves have been subject to material erosion for a long time, resulting in friction, causing severe impact wear, which cannot meet normal production requirements, and also resulting in a shortened service life of the equipment. Currently, wear-resistant materials, such as ceramic materials and polymer composite materials, are commonly used for ball valve wear, and the Meijiahua technical system is widely used. Polymer materials have excellent adhesive properties and ultra-strong wear resistance, which safely solves the drawbacks of frequent metal wear and ensure the normal production of enterprise equipment. Moreover, the unique ceramic material and special surface strengthening agent in the material make it superior to any steel or even better than ceramic tiles in terms of wear resistance and physical impact resistance in harsh dry grinding environments. The incompatibility between the product and coal is an ideal material for preventing coal accumulation.
Installation and use
1. Indoor devices or outdoor applications with protective methods;
2. Outdoor outdoor devices, with wind, sand, rain, sunlight, and other erosion;
3. Have a flammable, explosive gas or dust environment;
4. Environment in humid and dry tropical regions;
5. The temperature of the pipeline medium is as high as 450 ℃ or above;
6. The ambient temperature is below - 20 ℃;
7. Vulnerable to flooding or immersion;
8. Environments with radioactive substances (nuclear power plants and radioactive substance test devices);
9. Environment on ships or docks (with salt fog, mold, and humidity);
10. Places with severe vibration; Places prone to fire;
For electric ball valves in the above environment, their electric device structure, materials, and protection methods are different. Therefore, the corresponding valve electric device should be selected based on the above obligation environment. According to engineering control requirements, the control function of electric ball valves is accomplished by electric devices. The purpose of applying electric ball valves is to achieve non manual electrical or computer control of the opening, closing, and regulating linkage of valves. The application of electric devices is no longer just about saving labor. Due to the significant differences in the function and quality of products from different manufacturers, the selection of electric devices and the selection of valves are equally important to the project. Due to the ever-increasing requirements for industrial automation, on the one hand, the application of electric valves is increasing, and on the other hand, the control requirements for electric valves are becoming increasingly high and complex. Therefore, the design of electric valves in terms of electrical control is always updated. With the continuous improvement of usage requirements and the popularization and application of computers, new and diverse electrical control methods will always appear. Regarding the overall control of electric valves, attention should be paid to selecting the control method of electric valves. For example, depending on the needs of the project, whether to apply centralized control or single control, whether to interact with other equipment, sequence control, or computer sequence control, the control principles are different. The valve electric device manufacturer's sample only provides standard electrical control principles, so the application department should conduct technical disclosure with the electric device consumer factory to clarify the technical requirements.
Hard seal installation
1) Remove the protective covers on both sides of the flange end, and flush and clean with the valve fully open.
2) Before installation, the complete machine should be tested according to the specified signal (electrical or pneumatic) (to prevent vibration caused by transportation from affecting the performance), and can only be installed online after passing the test (wiring according to the wiring diagram of the electric actuator).
3) Before preparing to connect to the pipeline, it is necessary to flush and remove residual 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 for lifting 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 must not be sagging or bear external forces. Pipe supports or supports can be used to eliminate the deviation of the pipeline.
7) After connecting to the pipeline, please cross lock the flange connecting bolts with the specified torque.
Applicable occasions
Because ball valves typically use rubber, nylon, and polytetrafluoroethylene as seat sealing ring materials, their use temperature is limited by the seat sealing ring material. The cut-off function of ball valves is achieved by pressing metal balls against plastic valve seats under the action of media (floating ball ball valves). Under a certain contact pressure, the valve seat sealing ring undergoes elastic-plastic deformation in local areas. This deformation can compensate for the manufacturing accuracy and surface roughness of the ball, ensuring the sealing performance of the ball valve.
Due to the fact that the valve seat sealing ring of a ball valve is usually made of plastic, it is important to consider the fire resistance and fireproofing of the ball valve when selecting its structure and performance. Especially in petroleum, chemical, metallurgical, and other departments, when using ball valves in equipment and pipeline systems with flammable and explosive media, attention should be paid to fire resistance and fireproofing.
Generally, it is recommended to use ball valves in pipeline systems with two-position regulation, strict sealing performance, mud, wear, necking channels, rapid opening and closing action (1/4 turn opening and closing), high pressure cutoff (large pressure difference), low noise, cavitation and gasification, small leakage to the atmosphere, small operating torque, and low fluid resistance.
Ball valves are also suitable for lightweight structures, low pressure cutoff (low pressure differential), and corrosive media in pipeline systems. Ball valves can also be used in cryogenic (cryogenic) devices and piping systems. In the oxygen pipeline system of the metallurgical industry, it is necessary to use ball valves that have undergone strict degreasing treatment. When the main pipeline in oil and gas pipelines needs to be buried underground, it is necessary to use a full bore welded ball valve. When regulating performance is required, ball valves with special structures with V-shaped openings need to be selected. In petroleum, petrochemical, chemical, electric power, and urban construction, metal to metal sealed ball valves can be selected for pipeline systems with operating temperatures above 200 degrees Celsius.
Operational Use
1) Before operation, make sure that the pipelines and valves have been flushed.
2) The operation of the valve drives the valve rod to rotate according to the input signal size of the actuator: when the valve rotates 1/4 turn (90 °) in the forward direction, the valve is turned off. The valve opens when rotated in reverse direction by 1/4 turn (90 °).
3) When the actuator direction indicator arrow is parallel to the pipeline, the valve is in the open state; When the arrow is perpendicular to the pipeline, the valve is closed.
Advantages and disadvantages
Advantages: ① Low flow resistance (actually 0); ② It can be reliably applied to corrosive media and low boiling point liquids because it does not get stuck during operation (when there is no lubricant) Full sealing can be achieved in a large pressure and temperature range; ④ It can achieve rapid opening and closing, and the opening and closing time of some structures is only 0.05~0.1s to ensure that it can be used in the automation system of the test bench. When quickly opening and closing the valve, there is no impact during operation. ⑤ The spherical closure can be automatically positioned at the boundary position; ⑥ The working medium is reliably sealed on both sides; ⑦ During full opening and full closing, the sealing surfaces of the ball and valve seat are isolated from the medium, so the medium passing through the valve at high speed will not cause erosion of the sealing surface; ⑧ With compact structure and light weight, it can be considered as a reasonable valve structure for low-temperature medium systems; ⑨ The valve body is symmetrical, especially the welded valve body structure, which can well withstand the stress from the pipeline; ⑩ The closing element can withstand the high pressure difference during closing The ball valve with a fully welded body can be directly buried underground, preventing the valve internals from being corroded, and has a high service life of up to 30 years. It is an ideal valve for oil and natural gas pipelines.
Disadvantages: ① Because the main valve seat sealing ring material for ball valves is polytetrafluoroethylene, it is inert to almost all chemical substances, and has comprehensive characteristics such as low friction coefficient, stable performance, non aging, wide range of temperature applications, and excellent sealing performance. However, the physical characteristics of polytetrafluoroethylene, including its high coefficient of expansion, sensitivity to cold flow, and poor thermal conductivity, require that the design of the valve seat seal must revolve around these characteristics. Therefore, when the sealing material hardens, the reliability of the seal is destroyed. Moreover, the temperature resistance level of polytetrafluoroethylene is relatively low, and it can only be used at temperatures below 180 ℃. Beyond this temperature, the sealing material will age. When considering long-term use, it is generally not used at 120 ℃. ② Its regulating performance is worse than that of a shut-off valve, especially for pneumatic valves (or electric valves).
