Automatic ultrasonic testing is refers to the use of mechanical devices automatically move probe to achieve automatic scan of workpiece tested in the process of moving to use different ways to realize different ultrasonic wave type. Such as the different coupling method for structural steel pipe automated testing. The records of the results of the test of the workpiece can be automatically recorded in a particular medium, such as the pen type record of paper tape, electrical, computer storage devices, etc.), you can also automatically tag (painting, printing, etc.) on the workpiece. It also can do automatic sorting of qualified and unqualified artifacts and so on. Automatic ultrasonic testing system usually also has the monitoring device (such as oscilloscope, flaw detector display screens and computer monitor screen, etc.), facilitate testing personnel according to signal detection monitoring system work is normal. Automatic ultrasonic testing system can be divided into two categories:
1. The on-line automatic ultrasonic testing system of API mild steel pipe
This is an automatic production line process (station), it is not used only to judge the workpiece tested qualified or not and automatic sorting or tag spray (standard) and the detection speed, detection system of the continuous running time, it also can judge the work environment conditions (such as high temperature, vibration, noise, etc.) of adaptability and detection systems to protect themselves, etc.
2. Offline (not online) automatic or semi-automatic ultrasonic testing system which is in the process of production as a separate the inspection process, it can be divided into two types of automatic and semi-automatic.
1) Off-line automatic ultrasonic testing system
All except sensitivity adjustment and the machine maintenance work steps, such as front-rear and defect alarm and record, tag, are all depend on the device itself automatically, such as the many domestic large enterprises currently have been using the application of the steel plate automatic ultrasonic testing system
2) Offline semi-automatic ultrasonic testing system of API steel pipe
Part or parts of API steel pipe working procedure needs to be done with artificial, such as checked material defects or workpiece loading and unloading and loading, tags, etc. For example in the aviation industry to the turbine and compressor disk disc parts and parts of semi-automatic water beam type ultrasonic testing system. With the development of science and technology progress, the domestic ultrasonic testing is most used the API steel pipe automated testing, automatic detection of main advantage is: Due to the ultrasonic probe and checked materials or workpiece automatically relative motion, compared with manual testing, it can guarantee acoustic coupling performance is stable; It can do rapid detection of bulk API carbon steel pipe materials to conduct a comprehensive inspection of large area, which has the features of high speed and high efficiency; It can automatically record test results.
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2017年1月16日星期一
The Long History of Welded Steel Pipe
Over the last decade, welded steel pipe has been developed and improved so that welded steel pipe has a long history and welds can be made with consistent high quality and high productivity. And such advanced welding systems are available from several major pipeline equipment suppliers. As a matter of fact, the development of welded steel pipe can be summarized in different periods. In the 1930s, the first mechanized arc welded steel pipe was developed with a 35 degree arc with the help of angle weld preparation, stringer beads, and a narrow groove weld preparation in order to achieve side wall penetration. To be more specific, the welding head of the welded steel pipe was made with two bugs clamped on either side of the pipe and turned downwards from the 12 o'clock position to the 6 o'clock position. In the 1960s, internal welding machine was invented and used in the making of the welded steel pipe. Internal welding machine allow more than three welding torches to operate at the same time.
And external root welding techniques were developed during the same period with the advent of internal copper ring. In the 1970s, root welding techniques were used to produce the carbon steel pipe. Previously small diameter pipes and closing welds in larger diameter lines could not be internally welded without some sort of backing. The introduction of modern power supplies with control of metal transfer has made possible the internal welding without any backing. For example, a type of surface tension transfer process can be used with a root gap to achieve high-quality root runs, which is operated by detecting both the short circuit and the incipient rupture of the metal ridge. Better quality welded steel pipe can be manufactured thanks to the adjustable welding currents. And a stable transfer can be achieved at low-heat input and with little or no spatter.
According to the long history of welded steel pipe, the original welding systems of welded steel pipe make use of torches and wire feeds. In the 1980s, a dual torch welding system on one welding bug was introduced, which has been extensively used in a number of structural steel pipe manufacturers. To be more specific, the efficiency of the welding processes determines the properties and specifications of the welded steel pipe required by the customers, which takes on increasing significance as the wall thickness and diameter of welded steel pipe increase over the years. The introduction of the gas metal arc welding process offers further possibilities to increase the productivity of welded steel pipe. This special process typically uses a single torch with two contact tips to feed two wires into a single weld pool. Thus high welding speeds as well as excellent welding results can be assured. In some case more than two tandem torches can be used on one welding bug so as to further reduce the welding times while manufacturing DSAW steel pipe.
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And external root welding techniques were developed during the same period with the advent of internal copper ring. In the 1970s, root welding techniques were used to produce the carbon steel pipe. Previously small diameter pipes and closing welds in larger diameter lines could not be internally welded without some sort of backing. The introduction of modern power supplies with control of metal transfer has made possible the internal welding without any backing. For example, a type of surface tension transfer process can be used with a root gap to achieve high-quality root runs, which is operated by detecting both the short circuit and the incipient rupture of the metal ridge. Better quality welded steel pipe can be manufactured thanks to the adjustable welding currents. And a stable transfer can be achieved at low-heat input and with little or no spatter.
According to the long history of welded steel pipe, the original welding systems of welded steel pipe make use of torches and wire feeds. In the 1980s, a dual torch welding system on one welding bug was introduced, which has been extensively used in a number of structural steel pipe manufacturers. To be more specific, the efficiency of the welding processes determines the properties and specifications of the welded steel pipe required by the customers, which takes on increasing significance as the wall thickness and diameter of welded steel pipe increase over the years. The introduction of the gas metal arc welding process offers further possibilities to increase the productivity of welded steel pipe. This special process typically uses a single torch with two contact tips to feed two wires into a single weld pool. Thus high welding speeds as well as excellent welding results can be assured. In some case more than two tandem torches can be used on one welding bug so as to further reduce the welding times while manufacturing DSAW steel pipe.
More information,pls visit:Hunan great steel pipe co.,ltd
How to Find Reliable Welded Steel Pipe Operators
There are a variety of safety regulations concerning the operation and the installation of the welded steel pipe. To begin with, operators of the carbon steel pipe line are expected to implement and maintain a corrosion control program for their piping system. In general, the procedures consist of a series of installation, operation, and maintenance activities during different periods of time. As a matter of fact, for different welded steel pipe lines, the procedures may vary a great deal. More importantly, professionals well qualified in pipeline safety control methods are needed to carry out these procedures in an effective manner. For instance, operators or contractors of the welded steel pipe lines may hire qualified personnel to develop and carry out a safety control program from an array of educational institutions as well as scientific groups.
What is more, there are many consultants and experts who specialize in the safety of the mild steel pipe lines. Another source is an experienced pipe line engineer or technician who has worked in the piping industry for more than ten years. With their knowledge and skills, such experts of the welded steel pipe lines may be able to implement safety protection for small welded steel pipe operators, or refer them to local qualified engineers. Moreover, it is recommended that operators the welded steel pipe lines first contact the local piping industry association to see if any engineer or technician can be dispatched to do the job.
What is more, these welded steel pipe operators not only strictly conform to the safety regulation standard but also has a long tradition of excellent service and product quality. As a matter of fact, some welded steel pipe operators are capable of producing full line welded steel pipes ranging from one quarter to 12 nominal sizes according to ASTM standards. And the applications of their structural steel pipe can be adapted to the customers' requirements. For instance, ASTM A55 welded steel pipe is in general used for mechanical and pressure applications. It can also be used in steam, water, gas and air lines. In addition, more than three hundred different combinations of welded steel pipe finish, end treatments and lengths are available with these operators.
For instance, they offer a wide range of surface finishes, including black, bare, galvanized, uncoated, pickled, and oiled. And such end finishes as roll groove and cut groove are also available. Reliable manufacturing environments and techniques ensure that all the welded steel pipe products will conform to the ISO Quality Management Systems at minimum. More important, some welded steel pipe operators are strategically located the first-tier cities in different countries so that they carry a large inventory and can deliver the welded steel pipe products quickly.
What is more, there are many consultants and experts who specialize in the safety of the mild steel pipe lines. Another source is an experienced pipe line engineer or technician who has worked in the piping industry for more than ten years. With their knowledge and skills, such experts of the welded steel pipe lines may be able to implement safety protection for small welded steel pipe operators, or refer them to local qualified engineers. Moreover, it is recommended that operators the welded steel pipe lines first contact the local piping industry association to see if any engineer or technician can be dispatched to do the job.
What is more, these welded steel pipe operators not only strictly conform to the safety regulation standard but also has a long tradition of excellent service and product quality. As a matter of fact, some welded steel pipe operators are capable of producing full line welded steel pipes ranging from one quarter to 12 nominal sizes according to ASTM standards. And the applications of their structural steel pipe can be adapted to the customers' requirements. For instance, ASTM A55 welded steel pipe is in general used for mechanical and pressure applications. It can also be used in steam, water, gas and air lines. In addition, more than three hundred different combinations of welded steel pipe finish, end treatments and lengths are available with these operators.
For instance, they offer a wide range of surface finishes, including black, bare, galvanized, uncoated, pickled, and oiled. And such end finishes as roll groove and cut groove are also available. Reliable manufacturing environments and techniques ensure that all the welded steel pipe products will conform to the ISO Quality Management Systems at minimum. More important, some welded steel pipe operators are strategically located the first-tier cities in different countries so that they carry a large inventory and can deliver the welded steel pipe products quickly.
2017年1月13日星期五
Importance of Right Filler Metal for Welded Steel Pipe
When welded steel pipe is in the process of welding, there is a big potential threat which is called hot cracking that occurs immediately upon completion of the weld. Because of its larger grain structure, this material is particularly susceptible to the defect. Right filler metal, as well as proper heat input and post-weld cooling, is vital to cracking prevention and corrosion resistance coating steel pipe during the welding process.
Welded steel pipe should be matched with right filler metals based on their chemical and mechanical features. Luckily, it is easier for this kind pipe to make this match than many other materials. The grade of welded steel pipe that will be used for application can be affected by the intended service condition, and the grade of material has a great influence on the filler metal selection. For example, it is better for welded steel pipe with 304L to choose filler metal with American Welding Society, but 316 welded steel pipes should be matched with a 316L filler metal. Sometimes, we can also have to weld steel pipe to carbon steel, so a 309 grade filler metal is proper.
The final weld of the welded steel pipe can be integrated because the filler metals contain alloy. In addition, we usually prevent the pipe from corrosion by chromium and molybdenum. Molybdenum can also be useful for good high temperature and if weld strength needs to be increased, the nickel may be useful. The addition is not only used to maintain weld poop fluidity, but also stabilize the amount of austenite in the weld, which will in turn be helpful for refining the grain structure of the weld and crack resistance.
One kind of stainless steels which is known as the ferrite number is popular among engineers and designers. The ferrite number can be applied to measure the amount of ferrite versus austenite in the structure of the material. The ability of carbon steel pipe to resist cracking and corrosion can be indicated by the ferrite number. Generally, we use the chemistry of the material to determine the amount of ferrite present. When welding steel, it usually needs to reach a maximum ferrite number, but some special applications may require higher ferrite numbers.
More information,pls visit:Hunan great steel pipe co.,ltd
Welded steel pipe should be matched with right filler metals based on their chemical and mechanical features. Luckily, it is easier for this kind pipe to make this match than many other materials. The grade of welded steel pipe that will be used for application can be affected by the intended service condition, and the grade of material has a great influence on the filler metal selection. For example, it is better for welded steel pipe with 304L to choose filler metal with American Welding Society, but 316 welded steel pipes should be matched with a 316L filler metal. Sometimes, we can also have to weld steel pipe to carbon steel, so a 309 grade filler metal is proper.
The final weld of the welded steel pipe can be integrated because the filler metals contain alloy. In addition, we usually prevent the pipe from corrosion by chromium and molybdenum. Molybdenum can also be useful for good high temperature and if weld strength needs to be increased, the nickel may be useful. The addition is not only used to maintain weld poop fluidity, but also stabilize the amount of austenite in the weld, which will in turn be helpful for refining the grain structure of the weld and crack resistance.
One kind of stainless steels which is known as the ferrite number is popular among engineers and designers. The ferrite number can be applied to measure the amount of ferrite versus austenite in the structure of the material. The ability of carbon steel pipe to resist cracking and corrosion can be indicated by the ferrite number. Generally, we use the chemistry of the material to determine the amount of ferrite present. When welding steel, it usually needs to reach a maximum ferrite number, but some special applications may require higher ferrite numbers.
More information,pls visit:Hunan great steel pipe co.,ltd
The Typical Process of the Welded Steel Pipe
The ERW steel pipe, which is the Electric Resistance Welded steel pipe, begins as a coiled plate of steel with appropriate thickness and specific width in its processing. This kind of welded steel pipe is cold formed. In the manufacturing process, pull the ribbon through a series of rollers to form it into a cylindrical tube. An electric charge should be used to heat the edges so that they can be welded together when the edges of the cylindrical plate come together. The electric resistance welded steel pipe can be produced at a high speed in continuous lengths up to 115'. The wall thicknesses and outside dimensions that the pipe produces is uniform, and the electric resistance welded pipe can be made in a variety of specifications. However, sometimes this kind of pipe needs minimum tonnage so that it can be set up on a specific size and has long lead times.
The name of the DSAW steel pipe comes from the process that the welding arc is submerged when it happens. When the welding temperatures are heated, the flux is useful for preventing the weld area from impurities in the air. Only when the inside welds and outside welds are performed and the welding be accomplished in separate processes. Therefore, the pipe then can be looked as double submerged arc welded. This kind of process is suitable for three common types of pipe: U&O Press, Rolled and Welded, Spiral weld.
The spiral welded steel pipe, which is in a spiral form, has a DSAW seam the entire length. We can apply the angle of the steel that is de-coiled against the forming head to determine the outside diameter of the spiral welded pipe. The angle that is used is more acute, and then the diameter that is determined will be greater. The spiral structural steel pipe can be used in more places because of the production of large, hot rolled coils of sufficient width and the development of dependable non-destructive testing methods. The lengths up to 115 feet in either ID or OD dimensions up to 144 inches are suitable for the roll of the spiral welded pipe. The contractor may have an advantage of short term changes because of the slow manufacturing process. However, the slow manufacturing process may have a bad effect if the large tonnages are needed with a short lead time. The spiral welded steel pipe has limit specifications.
The name of the DSAW steel pipe comes from the process that the welding arc is submerged when it happens. When the welding temperatures are heated, the flux is useful for preventing the weld area from impurities in the air. Only when the inside welds and outside welds are performed and the welding be accomplished in separate processes. Therefore, the pipe then can be looked as double submerged arc welded. This kind of process is suitable for three common types of pipe: U&O Press, Rolled and Welded, Spiral weld.
The spiral welded steel pipe, which is in a spiral form, has a DSAW seam the entire length. We can apply the angle of the steel that is de-coiled against the forming head to determine the outside diameter of the spiral welded pipe. The angle that is used is more acute, and then the diameter that is determined will be greater. The spiral structural steel pipe can be used in more places because of the production of large, hot rolled coils of sufficient width and the development of dependable non-destructive testing methods. The lengths up to 115 feet in either ID or OD dimensions up to 144 inches are suitable for the roll of the spiral welded pipe. The contractor may have an advantage of short term changes because of the slow manufacturing process. However, the slow manufacturing process may have a bad effect if the large tonnages are needed with a short lead time. The spiral welded steel pipe has limit specifications.
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Special Filler Metals of Welded Steel Pipe
The first one is flux-cored wires. When welding out of position on thick-walled welded steel pipe, it is better to choose gas-shielded flux-cored wire to achieve high deposition rates. This kind of filler metal can weld out of position without a special power, and the flux coating on the wire can be considered as a dam which can hold the molten weld pool in place. Therefore, the flux –cored wires are useful for improving productivity. However, there are some disadvantages when using the flux-cored wires in the welded steel pipe. Higher levels of smoke may be produced and a slag may be generated by the wires. Then both between passes and after the cap pass, the welding operators will need to chip or grind in, which in turn leads to greater downtime for clean up.
The other kind is metal-cored wires. When welding structural steel pipe, the metal-cored wires are accepted more and more widely. The available diameters of the metal-cored wires range from 0.035- to 1/16-inch. In order to weld out of position, the pulsing or advanced short-circuit processes, with which the metal-metal wires can be applied to weld from root to the cap, are needed by stainless steel metal-cored wire. What is more, the welded steel pipe with these kinds of wires can provide greater productivity. One disadvantage to metal-cored wires is their cost. Though the metal-cored wires are more expensive, the productivity and quality improvements outweigh the cost.
The third one is solid wire. When welding thicker-walled welded steel pipe, we usually choose solid wires which must use a special power source to weld out of position. If the welded steel pipe is being rotated, these filler metals can be used to weld fill and cap passes in the flat or horizontal position. In addition, solid wires are useful for welding out of position for root, fill and cap passes. However, for welded steel pipe, it is more difficult to match the chemistry. Then the availability of the filler metals may be influenced.
The last one is DSAW steel pipe. SMAW (shielded metal arc welding) electrodes are of great importance for welded steel pipe because of the availability and familiarity of the filler metal. However, compared with other filler metals, the SMAW electrodes are slower and less efficient.
The other kind is metal-cored wires. When welding structural steel pipe, the metal-cored wires are accepted more and more widely. The available diameters of the metal-cored wires range from 0.035- to 1/16-inch. In order to weld out of position, the pulsing or advanced short-circuit processes, with which the metal-metal wires can be applied to weld from root to the cap, are needed by stainless steel metal-cored wire. What is more, the welded steel pipe with these kinds of wires can provide greater productivity. One disadvantage to metal-cored wires is their cost. Though the metal-cored wires are more expensive, the productivity and quality improvements outweigh the cost.
The third one is solid wire. When welding thicker-walled welded steel pipe, we usually choose solid wires which must use a special power source to weld out of position. If the welded steel pipe is being rotated, these filler metals can be used to weld fill and cap passes in the flat or horizontal position. In addition, solid wires are useful for welding out of position for root, fill and cap passes. However, for welded steel pipe, it is more difficult to match the chemistry. Then the availability of the filler metals may be influenced.
The last one is DSAW steel pipe. SMAW (shielded metal arc welding) electrodes are of great importance for welded steel pipe because of the availability and familiarity of the filler metal. However, compared with other filler metals, the SMAW electrodes are slower and less efficient.
More information,pls visit:Hunan Great Steel Pipe Co.,ltd.
Utility and Usage of Carbon Welded Steel Pipe
As the name implies, the main constituents of welded steel pipe is steel and carbon. Because of to the composition of these pipes, they are nicely suited for commercial and geothermal applications due to the reality of the tensile power they offer. These pipes are seamless and for that reason confirm to be of outstanding electricity as essential oil pipelines or as transporters of other fluids. The broad distribute utilization of the seamless carbon steel pipes is due to the reality of the composition and the advantages that they offer. These pipes are an apparent selection for heavy requirement commercial performs due to the tensile power of these pipes. Be it the making or mammoth ships, or even the performing elements of massive machinery, these pipes endure the stress nicely sufficient to invoke self-confidence in its end users.
When security and durability are of concern, these welded steel pipes pass the check with elan. The carbon steel pipe are resistant to vibration, shock, water stress, fire, and heavy force. For that reason any framework constructed of these pipes is considerably safe and sound from organic calamities like hurricanes, earthquakes, and tornados, fire and lightning, and also harmful floods. Steel is the most beneficial compound to resist cracks, so there is no dread of the pipes separating in circumstance of heavy stress on them. If a single decides to create frameworks underground, utilizing these pipes could be a sensible choice, as they will not rot as opposed to wooden.
The pipes are also utilized as transporters of fluids due to the reality the mixture of carbon and steel offers go up to an extremely ductile, elastic, and malleable compound. This creates it simpler to produce pipes that are slender, yet long lasting. They are as little as 1/8 inch external diameter to as huge as 72 inches external diameter. One can pick from carbon steel pipes of different diameters to transport fluids like essential oil, petroleum, organic fuel for example. Getting seamless, these pipes do not leak as there are no joints and fluid transport can be performed without dread any sort of leakage that could end result in an automobile accident. The reality that carbon steel pipes can be created slenderer than welded steel pipe created of other materials like copper creates it evident that the price of manufacturing these mild steel pipe will be much less than all those of its rivals. Yet, the advantages of these pipes outshine the relaxation that is out there in the industry. It is powerful, lengthy lasting, leak evidence, and separate cost-free. So various capabilities decrease the require to replace the pipes and this in turn decreases the price a single would have to regularly incur in this kind of scenarios.
Using welded steel pipe is one more way to preserving a cordial romantic relationship with dynamics? The structural steel pipe is dynamics' product or service, and steel manufacturing has also grown to be natural environment friendly. Following total utilization, steel is recycled and reutilized. This procedure creates it quick to retain the earth clean up.
More information,pls visit:Hunan great steel pipe co.,ltd
When security and durability are of concern, these welded steel pipes pass the check with elan. The carbon steel pipe are resistant to vibration, shock, water stress, fire, and heavy force. For that reason any framework constructed of these pipes is considerably safe and sound from organic calamities like hurricanes, earthquakes, and tornados, fire and lightning, and also harmful floods. Steel is the most beneficial compound to resist cracks, so there is no dread of the pipes separating in circumstance of heavy stress on them. If a single decides to create frameworks underground, utilizing these pipes could be a sensible choice, as they will not rot as opposed to wooden.
The pipes are also utilized as transporters of fluids due to the reality the mixture of carbon and steel offers go up to an extremely ductile, elastic, and malleable compound. This creates it simpler to produce pipes that are slender, yet long lasting. They are as little as 1/8 inch external diameter to as huge as 72 inches external diameter. One can pick from carbon steel pipes of different diameters to transport fluids like essential oil, petroleum, organic fuel for example. Getting seamless, these pipes do not leak as there are no joints and fluid transport can be performed without dread any sort of leakage that could end result in an automobile accident. The reality that carbon steel pipes can be created slenderer than welded steel pipe created of other materials like copper creates it evident that the price of manufacturing these mild steel pipe will be much less than all those of its rivals. Yet, the advantages of these pipes outshine the relaxation that is out there in the industry. It is powerful, lengthy lasting, leak evidence, and separate cost-free. So various capabilities decrease the require to replace the pipes and this in turn decreases the price a single would have to regularly incur in this kind of scenarios.
Using welded steel pipe is one more way to preserving a cordial romantic relationship with dynamics? The structural steel pipe is dynamics' product or service, and steel manufacturing has also grown to be natural environment friendly. Following total utilization, steel is recycled and reutilized. This procedure creates it quick to retain the earth clean up.
More information,pls visit:Hunan great steel pipe co.,ltd
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