This is steel pipe for pipeline transportation systems in the petroleum and natural gas industries. API 5L is suitable for conveying gas, water, and oil. Size range is limited only by manufacturer’s capabilities.
API line pipe factory production specifications adhere to the International Organization for Standardization ISO 3183, which standardizes pipeline transportation systems within the materials, equipment and offshore structures for petroleum, petrochemical, and natural gas industries. The technical committee authoring the standards recognized that there are two basic Product Specifications Levels (PSL) of technical requirements and therefore developed PSL 1 and PSL 2. PSL 1 is a standard quality for line pipe where PSL 2 contains additional chemical, mechanical properties, and testing requirements.
Grades covered by this specification are A25 ,A ,B (and the following "X" Grades), X42, X46, X52, X56, X60, X65, X70, X80. The two digit number following the "X" indicates the Minimum Yield Strength (in 000's psi) of pipe produced to this grade.
2019年5月27日星期一
Carbon steel pipe and its application
The term carbon steel pipe is quite broad in scope and can be used to describe a wide range of metal tubular goods whose main alloying element is carbon. Although many of the same manufacturing principles apply to both carbon steel pipe and various similar alloy tubular goods, the focus of this narrative will be on the manufacturing process of mild carbon steel pipe goods commonly used for oil and gas as well as water transmission, structural applications, general purpose casing, piling, and mechanical components.
Carbon steel pipe manufacturing starts out by arriving at the pipe mill in the form of either a billet (basically a large solid steel bar) or a coil (imagine a roll of toilet paper made out of steel). Depending on the manufacturing method used by the mill, these billets or coils will be processed to yield the finished end product.
Manufacturer of industrial carbon steel pipes in a variety of grades for structural piping application. Available in 5 to 160, XH, and XXH schedules, plain, beveled, threaded, and victualic grooved end finishes, and cement lined, concrete, and passivated coatings. Serves industries such as oilfields, refinery, construction, shipping, and maritime. Special schedules also available.
Carbon steel pipe manufacturing starts out by arriving at the pipe mill in the form of either a billet (basically a large solid steel bar) or a coil (imagine a roll of toilet paper made out of steel). Depending on the manufacturing method used by the mill, these billets or coils will be processed to yield the finished end product.
Manufacturer of industrial carbon steel pipes in a variety of grades for structural piping application. Available in 5 to 160, XH, and XXH schedules, plain, beveled, threaded, and victualic grooved end finishes, and cement lined, concrete, and passivated coatings. Serves industries such as oilfields, refinery, construction, shipping, and maritime. Special schedules also available.
Small Diameter Seamless Steel Tube
The steel pipe industry has developed rapidly in recent years, and its types are also emerging. Today, we will introduce the characteristics and uses of small-diameter seamless steel tubes.
The small-diameter seamless steel pipe is a circular, square and rectangular steel seamless steel pipe with a hollow section and no seam at the periphery. The steel pipe is perforated with a steel ingot or a solid pipe blank, and then hot-rolled, cold-rolled or cold-drawn production process. The seamless steel pipe has a hollow section and is used as a pipe for conveying fluid. Compared with a solid steel such as round steel, the steel pipe is light in weight when it has the same bending and torsional strength, and is an economical section steel, which is widely used in manufacturing structures, parts and mechanical parts, such as oil drill pipes, automotive drive shafts, bicycle frames, and steel scaffolding used in construction.
According to the different production methods, it can be divided into hot-rolled tubes, cold-rolled tubes, cold-drawn tubes, extruded tubes, etc. Hot-rolled seamless tubes are generally produced on automatic rolling mill units.
The solid tube blank is inspected and the surface defects are cut to the required length, centered on the end face of the perforated end of the tube blank and then sent to the furnace for heating. The perforation is perforated at the perforator while continuously rotating and advancing, under the action of the roll and the head. The cavity is gradually formed into a hollow tube inside the tube blank, and then sent to the automatic tube rolling machine to continue rolling. The final machine is evenly wall-thickened, sizing according to the sizing (reducing diameter) machine, meeting the specification requirements, and producing by the continuous rolling tube unit. Hot-rolled seamless steel tubes are a more advanced method. If you want to obtain seamless tubes with smaller size and better quality, you must use cold rolling cold drawing or a combination of the two. Cold rolling is usually carried out on a two-roll mill.
The steel pipe is rolled in an annular hole type composed of a variable-section circular hole groove and a fixed conical head. The cold-drawn drawing is usually performed on a single-chain or double-chain cold drawing machine by pressing the tube blank to be heated. The perforated rod in the closed extrusion cylinder moves together with the extrusion rod to extrude the extrusion from the smaller orifice, which produces a smaller diameter steel tube. If you want to know more about other types of steel pipes, please pay attention to our website info and news.
http://www.xysteelpipe.com/info/Small-Diameter-Seamless-Steel-Tube-1411-1.htm
The small-diameter seamless steel pipe is a circular, square and rectangular steel seamless steel pipe with a hollow section and no seam at the periphery. The steel pipe is perforated with a steel ingot or a solid pipe blank, and then hot-rolled, cold-rolled or cold-drawn production process. The seamless steel pipe has a hollow section and is used as a pipe for conveying fluid. Compared with a solid steel such as round steel, the steel pipe is light in weight when it has the same bending and torsional strength, and is an economical section steel, which is widely used in manufacturing structures, parts and mechanical parts, such as oil drill pipes, automotive drive shafts, bicycle frames, and steel scaffolding used in construction.
According to the different production methods, it can be divided into hot-rolled tubes, cold-rolled tubes, cold-drawn tubes, extruded tubes, etc. Hot-rolled seamless tubes are generally produced on automatic rolling mill units.
The solid tube blank is inspected and the surface defects are cut to the required length, centered on the end face of the perforated end of the tube blank and then sent to the furnace for heating. The perforation is perforated at the perforator while continuously rotating and advancing, under the action of the roll and the head. The cavity is gradually formed into a hollow tube inside the tube blank, and then sent to the automatic tube rolling machine to continue rolling. The final machine is evenly wall-thickened, sizing according to the sizing (reducing diameter) machine, meeting the specification requirements, and producing by the continuous rolling tube unit. Hot-rolled seamless steel tubes are a more advanced method. If you want to obtain seamless tubes with smaller size and better quality, you must use cold rolling cold drawing or a combination of the two. Cold rolling is usually carried out on a two-roll mill.
The steel pipe is rolled in an annular hole type composed of a variable-section circular hole groove and a fixed conical head. The cold-drawn drawing is usually performed on a single-chain or double-chain cold drawing machine by pressing the tube blank to be heated. The perforated rod in the closed extrusion cylinder moves together with the extrusion rod to extrude the extrusion from the smaller orifice, which produces a smaller diameter steel tube. If you want to know more about other types of steel pipes, please pay attention to our website info and news.
http://www.xysteelpipe.com/info/Small-Diameter-Seamless-Steel-Tube-1411-1.htm
2019年5月26日星期日
What is Galvanized steel pipe?
Galvanized steel pipe is a steel pipe that has been coated with zinc. This coating protects the steel from corrosion. It is most commonly used for outdoor construction like fences and handrails, or for some interior plumbing. It is also sometimes called galvanized iron pipe.
The process of galvanization was first discussed by scientists in the 1770s, nearly 60 years before it was finally introduced in the 1830s. French engineer Stanislaus Tranquille Modeste Sorel took out the first patent for the process in 1937, and began manufacturing it soon after. By the 1850s, Europe was producing galvanized steel out of manufacturing plants located around the continent. The United States followed shortly thereafter, opening its first plant in the 1870s.
To create galvanized steel pipe, steel materials are placed into a molten bath of zinc. This process is also called hot dip galvanization. The two metals are chemically bound to one another in this process, and will therefore never separate, resulting in a more resistant and longer lasting version of steel.
This type of pipe is not suited to gas lines, but was very commonly used for full, in-home plumbing until the mid- to late 1900s, when copper replaced it as the pipe material of choice. It was discovered at that time that lime scale buildup occurred faster in galvanized steel pipe than in copper or plastic. It is still sometimes used indoors for plumbing, particularly for the replacement of small areas of pipe, in which the flow will not be greatly interrupted by sections of lime scale.
Outdoor applications are a more common use of galvanized steel pipe in the modern age. It is most likely to be seen on chain link fences or handrails. It is highly resistant to corrosion, which makes it a perfect choice for goods or materials that will be exposed to the elements on a regular basis.
Galvanized steel pipe is generally connected by threads on either end of a length of pipe. A small amount of adhesive is typically placed on the threads before screwing them together, in order to reinforce the connection. If no threads are available, the pipes and fittings can be welded together, although caution should be taken because the heat from welding can release dangerous zinc fumes into the air. Pipes can be cut using a cutoff saw or hacksaw.
The process of galvanization was first discussed by scientists in the 1770s, nearly 60 years before it was finally introduced in the 1830s. French engineer Stanislaus Tranquille Modeste Sorel took out the first patent for the process in 1937, and began manufacturing it soon after. By the 1850s, Europe was producing galvanized steel out of manufacturing plants located around the continent. The United States followed shortly thereafter, opening its first plant in the 1870s.
To create galvanized steel pipe, steel materials are placed into a molten bath of zinc. This process is also called hot dip galvanization. The two metals are chemically bound to one another in this process, and will therefore never separate, resulting in a more resistant and longer lasting version of steel.
This type of pipe is not suited to gas lines, but was very commonly used for full, in-home plumbing until the mid- to late 1900s, when copper replaced it as the pipe material of choice. It was discovered at that time that lime scale buildup occurred faster in galvanized steel pipe than in copper or plastic. It is still sometimes used indoors for plumbing, particularly for the replacement of small areas of pipe, in which the flow will not be greatly interrupted by sections of lime scale.
Outdoor applications are a more common use of galvanized steel pipe in the modern age. It is most likely to be seen on chain link fences or handrails. It is highly resistant to corrosion, which makes it a perfect choice for goods or materials that will be exposed to the elements on a regular basis.
Galvanized steel pipe is generally connected by threads on either end of a length of pipe. A small amount of adhesive is typically placed on the threads before screwing them together, in order to reinforce the connection. If no threads are available, the pipes and fittings can be welded together, although caution should be taken because the heat from welding can release dangerous zinc fumes into the air. Pipes can be cut using a cutoff saw or hacksaw.
Heat treatment of high frequency straight welded pipe after welding
Introduction of Heat Treatment of High Frequency Straight Seam Welded Pipe after Welding:
1.High frequency straight seam welded pipe after welding, the heat treatment is a new elimination of residual stress technology. Before welding, the material is preheated to the post-heat treatment temperature and the weld is continuously heated during the welding process to maintain this temperature. After the welding is completed, it is warmed by the heat-insulating cotton to cool it slowly. This method can effectively reduce the welding residual stress, improve the metal resistance to stress corrosion.
2.Non-destructive testing of the weld due to the pipeline in the water supply project is a large steel pipe, especially the thickness of t = 30mm steel pipe is used as a pipe bridge, it is necessary to bear the water pressure, but also bear the weight of the steel pipe and water bending moment, so the quality of the welding requirements are particularly high. For the pipe with t = 30mm thick large diameter steel pipe, the longitudinal seam and ring joints are belong to a class of welds, requiring 100% X-ray film inspection and 100% ultrasonic inspection; and the thickness t = 24mm buried steel pipe, longitudinal seam is a class of welding, 20% of the X-ray film inspection and 50% of the ultrasonic testing.
3.After welding, the heat treatment can effectively reduce the welding residual stress, and the higher the heat treatment temperature, the better the residual stress elimination effect. The heat treatment of large diameter steel pipe can also effectively improve the stress corrosion resistance of large diameter steel pipe. The higher the temperature after heat treatment, the more remarkable the improvement of stress corrosion resistance. Diffusion method Metal carbide coating technology is the workpiece placed in a special medium, the role of diffusion on the surface of the workpiece to form a layer of micron to tens of microns of metal carbide layer. Large diameter steel pipe within the anti-corrosion buried pipe and the tube of the anti-corrosion, are used galvanized iron wire mesh, spraying compressive strength of not less than 30N / mm2 cement mortar lining.
1.High frequency straight seam welded pipe after welding, the heat treatment is a new elimination of residual stress technology. Before welding, the material is preheated to the post-heat treatment temperature and the weld is continuously heated during the welding process to maintain this temperature. After the welding is completed, it is warmed by the heat-insulating cotton to cool it slowly. This method can effectively reduce the welding residual stress, improve the metal resistance to stress corrosion.
2.Non-destructive testing of the weld due to the pipeline in the water supply project is a large steel pipe, especially the thickness of t = 30mm steel pipe is used as a pipe bridge, it is necessary to bear the water pressure, but also bear the weight of the steel pipe and water bending moment, so the quality of the welding requirements are particularly high. For the pipe with t = 30mm thick large diameter steel pipe, the longitudinal seam and ring joints are belong to a class of welds, requiring 100% X-ray film inspection and 100% ultrasonic inspection; and the thickness t = 24mm buried steel pipe, longitudinal seam is a class of welding, 20% of the X-ray film inspection and 50% of the ultrasonic testing.
3.After welding, the heat treatment can effectively reduce the welding residual stress, and the higher the heat treatment temperature, the better the residual stress elimination effect. The heat treatment of large diameter steel pipe can also effectively improve the stress corrosion resistance of large diameter steel pipe. The higher the temperature after heat treatment, the more remarkable the improvement of stress corrosion resistance. Diffusion method Metal carbide coating technology is the workpiece placed in a special medium, the role of diffusion on the surface of the workpiece to form a layer of micron to tens of microns of metal carbide layer. Large diameter steel pipe within the anti-corrosion buried pipe and the tube of the anti-corrosion, are used galvanized iron wire mesh, spraying compressive strength of not less than 30N / mm2 cement mortar lining.
2019年5月20日星期一
Water gas pipe and galvanized steel pipe difference
The biggest difference between water gas pipeline and galvanized steel pipe is that the former is seamed steel pipe and its pressure bearing capacity is low, the later is seamless steel pipe and its pressure bearing capacity is high.
Water gas pipes are constituted by welded steel pipes with thick wall, its materials are different from galvanized steel pipes. Water gas pipe is made of low-carbon steel welded pipe. those Galvanized are called galvanized iron tubes. Those non-galvanized are called black pipes.
Galvanized steel pipe is divided into cold galvanized steel pipe and hot galvanized steel pipe. The electroplating of hot galvanized steel pipe is relatively strong, its zinc layer is thick, and there is a blue ring logo on the head of galvanized pipe. Cold galvanized steel pipe is also made by electroplating, but it is made with less technology, and its performance is far worse, no blue logo. Cold galvanized steel pipe has been banned, hot galvanized steel pipe is promoted temporary use by country.
Now the water gas pipelines used in the project are basically galvanized pipe, instrument air galvanized steel pipe and galvanized steel pipe of cable laying is using hot galvanized galvanized steel pipe to produce, since the hot galvanized pipe is more corrosion-resistant. The electrical piping on the project is thin-walled tube, it can not be under pressure.
Water gas pipes are constituted by welded steel pipes with thick wall, its materials are different from galvanized steel pipes. Water gas pipe is made of low-carbon steel welded pipe. those Galvanized are called galvanized iron tubes. Those non-galvanized are called black pipes.
Galvanized steel pipe is divided into cold galvanized steel pipe and hot galvanized steel pipe. The electroplating of hot galvanized steel pipe is relatively strong, its zinc layer is thick, and there is a blue ring logo on the head of galvanized pipe. Cold galvanized steel pipe is also made by electroplating, but it is made with less technology, and its performance is far worse, no blue logo. Cold galvanized steel pipe has been banned, hot galvanized steel pipe is promoted temporary use by country.
Now the water gas pipelines used in the project are basically galvanized pipe, instrument air galvanized steel pipe and galvanized steel pipe of cable laying is using hot galvanized galvanized steel pipe to produce, since the hot galvanized pipe is more corrosion-resistant. The electrical piping on the project is thin-walled tube, it can not be under pressure.
What is the cause of the straight pipe in seamless steel tube?
What is the cause of the straight pipe in seamless steel tube?
1. The influence of the rolling temperature of the seamless steel pipe: the rolling temperature is high, pressure is small, and the head wear is small, so that the inner straight defects are also reduced. However, the rolling temperature is too high, and the surface of the plug is easily burned to adhere to metal and iron sheets, which causes an increase in internal straight defects. Generally, the seamless steel pipe rolling temperature is about 1050 degrees Celsius.
2. The effect of the amount of deformation: generally, the amount of deformation is large, and the defects of the inner straight track are increased. When the total elongation coefficient is constant, the first pass extension coefficient is increased, and the second run length coefficient is decreased, so that the inner straight track defect can be reduced. Therefore, the second deformation can eliminate the inner straight path generated during the first deformation. However, the straight path at the roll gap cannot be eliminated because the head is not in contact with the metal here.
3. The effect of the lubricant: in order to reduce the coefficient of friction between the seamless steel pipe and the plug, it is possible to reduce the straight-line defects in the seamless steel pipe by spraying the lubricant into the capillary tube before feeding it to the rolling mill. When no lubricant is used, the number and depth of defects increase.
4. The shape of the head: the use of the spherical head can reduce the inner straight defect, because the ball top has many processing faces, the reduced wall area is narrow, the rolling force is small, and the metal and iron skin are not easily adhered on the head.
5. Rolled seamless steel pipe steel. Steel grades with high deformation resistance are likely to cause internal straight-track defects due to large rolling pressure.
6. The surface state of the head: it's mainly determined by heat treatment, the surface of the head should have a certain hardness and no cracks.
http://www.xysteelpipe.com/info/What-is-the-cause-of-the-straight-pipe-in-seamless-steel-tube-1402-1.htm
1. The influence of the rolling temperature of the seamless steel pipe: the rolling temperature is high, pressure is small, and the head wear is small, so that the inner straight defects are also reduced. However, the rolling temperature is too high, and the surface of the plug is easily burned to adhere to metal and iron sheets, which causes an increase in internal straight defects. Generally, the seamless steel pipe rolling temperature is about 1050 degrees Celsius.
2. The effect of the amount of deformation: generally, the amount of deformation is large, and the defects of the inner straight track are increased. When the total elongation coefficient is constant, the first pass extension coefficient is increased, and the second run length coefficient is decreased, so that the inner straight track defect can be reduced. Therefore, the second deformation can eliminate the inner straight path generated during the first deformation. However, the straight path at the roll gap cannot be eliminated because the head is not in contact with the metal here.
3. The effect of the lubricant: in order to reduce the coefficient of friction between the seamless steel pipe and the plug, it is possible to reduce the straight-line defects in the seamless steel pipe by spraying the lubricant into the capillary tube before feeding it to the rolling mill. When no lubricant is used, the number and depth of defects increase.
4. The shape of the head: the use of the spherical head can reduce the inner straight defect, because the ball top has many processing faces, the reduced wall area is narrow, the rolling force is small, and the metal and iron skin are not easily adhered on the head.
5. Rolled seamless steel pipe steel. Steel grades with high deformation resistance are likely to cause internal straight-track defects due to large rolling pressure.
6. The surface state of the head: it's mainly determined by heat treatment, the surface of the head should have a certain hardness and no cracks.
http://www.xysteelpipe.com/info/What-is-the-cause-of-the-straight-pipe-in-seamless-steel-tube-1402-1.htm
2019年5月17日星期五
Natural gas pipeline materials and their characteristics
Natural gas pipeline refers to the pipeline that transports the natural gas (including the production of oil associated gas) from the mined land or processing plant to the city gas distribution center or industrial enterprise users, also known as gas line. In the world pipeline overall length, natural gas pipe accounts for about half.
The steel pipe is the main material of the natural gas pipeline. Modern gas gathering lines and gas line are made of steel pipes those connected by welding. There are various kinds of steel pipe, including seamless steel pipe, spiral welded pipe, longitudinal welded pipe. Seamless steel pipe be appropriate for natural gas pipe that the diameter is below 529mm, and spiral welded pipe and longitudinal welded pipe are suitable for large diameter pipe.
Features of natural gas pipeline:
(1) The gas line system is a continuous closed conveyor system.
(2) From the transport, storage to the user, natural gas is with high pressure.
(3) Due to the small proportion of transported natural gas, the influence of static pressure head is much smaller than that of liquid. In design, when the height difference is less than 200 meters, the static pressure head is negligible, and the line is almost without limited by the longitudinal terrain.
(4) There is no harms of water dashing of water pipeline.
(5) Once an accident occurs, natural gas pipe is very dangerous and extensively affected. Once the natural gas pipeline rupture, it will release plenty of energy, and its tear length is longer. If the discharge of natural gas meets open fire, also easy to lead to fire.
The steel pipe is the main material of the natural gas pipeline. Modern gas gathering lines and gas line are made of steel pipes those connected by welding. There are various kinds of steel pipe, including seamless steel pipe, spiral welded pipe, longitudinal welded pipe. Seamless steel pipe be appropriate for natural gas pipe that the diameter is below 529mm, and spiral welded pipe and longitudinal welded pipe are suitable for large diameter pipe.
Features of natural gas pipeline:
(1) The gas line system is a continuous closed conveyor system.
(2) From the transport, storage to the user, natural gas is with high pressure.
(3) Due to the small proportion of transported natural gas, the influence of static pressure head is much smaller than that of liquid. In design, when the height difference is less than 200 meters, the static pressure head is negligible, and the line is almost without limited by the longitudinal terrain.
(4) There is no harms of water dashing of water pipeline.
(5) Once an accident occurs, natural gas pipe is very dangerous and extensively affected. Once the natural gas pipeline rupture, it will release plenty of energy, and its tear length is longer. If the discharge of natural gas meets open fire, also easy to lead to fire.
Anticorrosion technology for spiral welded pipe
We all know that the individual quality of spiral welded pipe is relatively large, so it must be stacked outdoors. But it is difficult to avoid being exposed to the sun and rain. So the rust problem has been puzzled the storage time and conditions of spiral welded pipe. Today, we need to carry out a comprehensive solution to the knowledge of anti-corrosion technology of spiral welded pipe.
The toolrust-removal of spiral welded pipe mainly uses steel wire brush and other tools to polish the steel surface, and then cleans and preheats the spiral welded pipe, which can remove loose or turnup mill scale, rust, welding slag and so on. Using manual tool to remove rust can reach Sa 2 level, using power tools can reach Sa 3 level. If there is steady oxide-scale adhering to the steel pipe surface, the effect of toolrust-removal is not ideal, it can not up to the depth of abrasion pattern that required by anti-corrosion construction.
Pickling refers to use solvents, emulsions to clean the surface of the spiral welded pipe (SSAW steel pipe) delivered by low pressure fluid, to achieve removing of oil, grease, dirt, lubricants, and similar organic matter, but it can not remove the rust, mill scale, welding flux, etc. on the surface of spiral welded pipe. So Pickling can only as an auxiliary mean in the anti-corrosion production. Manufacturer general use chemical and electrolytic two methods for pickling treatment, pipeline anti-corrosion technology only adopts chemical pickling, that can remove mill scale, rust, the old coating. And sometimes it can be used as re-treatment after derusting by sandblast. Although Chemical cleaning can make the surface to achieve a certain degree of cleanliness and roughness, but its anchor is shallow, and it is easy to cause stacking environment pollution of spiral pipe welding.
Reasonable using the means to clean the rusty pipe can ensure that spiral welded pipe serves the production for a long time and create more production efficiency.
The toolrust-removal of spiral welded pipe mainly uses steel wire brush and other tools to polish the steel surface, and then cleans and preheats the spiral welded pipe, which can remove loose or turnup mill scale, rust, welding slag and so on. Using manual tool to remove rust can reach Sa 2 level, using power tools can reach Sa 3 level. If there is steady oxide-scale adhering to the steel pipe surface, the effect of toolrust-removal is not ideal, it can not up to the depth of abrasion pattern that required by anti-corrosion construction.
Pickling refers to use solvents, emulsions to clean the surface of the spiral welded pipe (SSAW steel pipe) delivered by low pressure fluid, to achieve removing of oil, grease, dirt, lubricants, and similar organic matter, but it can not remove the rust, mill scale, welding flux, etc. on the surface of spiral welded pipe. So Pickling can only as an auxiliary mean in the anti-corrosion production. Manufacturer general use chemical and electrolytic two methods for pickling treatment, pipeline anti-corrosion technology only adopts chemical pickling, that can remove mill scale, rust, the old coating. And sometimes it can be used as re-treatment after derusting by sandblast. Although Chemical cleaning can make the surface to achieve a certain degree of cleanliness and roughness, but its anchor is shallow, and it is easy to cause stacking environment pollution of spiral pipe welding.
Reasonable using the means to clean the rusty pipe can ensure that spiral welded pipe serves the production for a long time and create more production efficiency.
Characteristics and application of small diameter spiral welded pipe
Although small caliber spiral welded pipe is small, its function is a lot. So what the features and uses of small diameter spiral welded pipe are?
Features of small-diameter spiral welded pipe:
The production process of spiral welded pipe is simple, but it has high production efficiency. It can use material to form a larger pipe diameter pipe, it can also use the same width of preform body to product pipes with different diameter. However, compared with the same LSAW steel pipe, the length of weld seam is increased by 30% to 100%, and its production rate is low. Therefore, the smaller diameter of the steel pipe mostly use straight welding, large diameter welded pipes mostly use spiral welded pipe.
Uses of small-diameter spiral welded pipe:
Spiral welded pipe is mainly used in tap water engineering, petrochemical industry, chemical industry, power industry, agricultural irrigation, urban construction, and it is one of the 20 key products for the development of China. It is used for liquid delivery: water supply, drainage. It is used for gas transmission: gas, steam, liquefied petroleum gas. It is used for the structure: piling pipe, bridge girder, the pipe for wharf, road, building structure and so on.
Features of small-diameter spiral welded pipe:
The production process of spiral welded pipe is simple, but it has high production efficiency. It can use material to form a larger pipe diameter pipe, it can also use the same width of preform body to product pipes with different diameter. However, compared with the same LSAW steel pipe, the length of weld seam is increased by 30% to 100%, and its production rate is low. Therefore, the smaller diameter of the steel pipe mostly use straight welding, large diameter welded pipes mostly use spiral welded pipe.
Uses of small-diameter spiral welded pipe:
Spiral welded pipe is mainly used in tap water engineering, petrochemical industry, chemical industry, power industry, agricultural irrigation, urban construction, and it is one of the 20 key products for the development of China. It is used for liquid delivery: water supply, drainage. It is used for gas transmission: gas, steam, liquefied petroleum gas. It is used for the structure: piling pipe, bridge girder, the pipe for wharf, road, building structure and so on.
2019年5月12日星期日
LSAW pipe meaning
Longitudinally Submerged Arc Welding pipe(abbreviated as LSAW pipe). The Longitudinally Submerged Arc Welding (LSAW) is produced by using a single plate as a raw material, pressing (rolling) the steel plate into a pipe blank in a mold or a molding machine, and adopting double-sided submerged arc welding and expanding the diameter. The finished product has a wide range of specifications, and the weld has good toughness, plasticity, uniformity and compactness, and has the advantages of large pipe diameter, thick pipe wall, high pressure resistance, low temperature resistance and corrosion resistance.
When constructing high-strength, high-toughness, high-quality long-distance oil and gas pipelines, most of the required steel pipes are large-diameter thick-walled straight seam submerged arc welded pipes. According to the API standard, in large oil and gas pipelines, the straight seam submerged arc welded pipe is the only designated pipe type when passing through Class I and Class 2 areas such as high-altitude zones, seabeds, and urban densely populated areas. According to different molding methods, it can be divided into:
UOE welded pipe: after the pre-bending of the single steel plate, U-forming, O-forming, internal welding, external welding, mechanical cold expansion and other processes;
JCOE welded pipe: it is according to the process of "J-C-O-E" pre-welding, forming, cold-expanding after welding;
HME welded pipe: It is formed by the "C-C-O" by the mandrel rolling method, and the process of cold expansion after welding.
The main technical parameters of LSAW (straight seam submerged arc welded pipe) are as follows:
Wall thickness: 6.4-23.8mm (0.252-0.94in) in X80 steel grade and 6.4-26.4mm (0.252-1.04in) in X70 steel grade. The wall thickness can be increased to varying degrees as the material is lowered.
Product standard: ISO3183-3, API Spec 5L, GB9711, etc.
Straight seam submerged arc welded steel pipe diameter up to Φ406.4-Φ1422.4mm
The steel pipe can be up to 12.2m long and the wall thickness is 6.4-26.4mm at the ×70 steel grade.
Main features of LSAW pipe:
1) The steel pipe has a longitudinal weld, and the inner and outer welds are welded by a submerged arc welding.
2) After the overall mechanical expansion treatment, the internal stress of the steel pipe is small and evenly distributed, which can effectively prevent stress corrosion cracking, high dimensional accuracy, and is convenient for on-site welding construction.
3) Using the process of pre-weld after-welding, the welding process is stable and the weld quality is high.
4) Welds are easy to achieve non-destructive testing during production and non-destructive testing in the field during use.
5) The product specification range is large, which can produce small diameter, large wall thickness and can also produce large diameter and large wall thickness steel pipe.
When constructing high-strength, high-toughness, high-quality long-distance oil and gas pipelines, most of the required steel pipes are large-diameter thick-walled straight seam submerged arc welded pipes. According to the API standard, in large oil and gas pipelines, the straight seam submerged arc welded pipe is the only designated pipe type when passing through Class I and Class 2 areas such as high-altitude zones, seabeds, and urban densely populated areas. According to different molding methods, it can be divided into:
UOE welded pipe: after the pre-bending of the single steel plate, U-forming, O-forming, internal welding, external welding, mechanical cold expansion and other processes;
JCOE welded pipe: it is according to the process of "J-C-O-E" pre-welding, forming, cold-expanding after welding;
HME welded pipe: It is formed by the "C-C-O" by the mandrel rolling method, and the process of cold expansion after welding.
The main technical parameters of LSAW (straight seam submerged arc welded pipe) are as follows:
Wall thickness: 6.4-23.8mm (0.252-0.94in) in X80 steel grade and 6.4-26.4mm (0.252-1.04in) in X70 steel grade. The wall thickness can be increased to varying degrees as the material is lowered.
Product standard: ISO3183-3, API Spec 5L, GB9711, etc.
Straight seam submerged arc welded steel pipe diameter up to Φ406.4-Φ1422.4mm
The steel pipe can be up to 12.2m long and the wall thickness is 6.4-26.4mm at the ×70 steel grade.
Main features of LSAW pipe:
1) The steel pipe has a longitudinal weld, and the inner and outer welds are welded by a submerged arc welding.
2) After the overall mechanical expansion treatment, the internal stress of the steel pipe is small and evenly distributed, which can effectively prevent stress corrosion cracking, high dimensional accuracy, and is convenient for on-site welding construction.
3) Using the process of pre-weld after-welding, the welding process is stable and the weld quality is high.
4) Welds are easy to achieve non-destructive testing during production and non-destructive testing in the field during use.
5) The product specification range is large, which can produce small diameter, large wall thickness and can also produce large diameter and large wall thickness steel pipe.
Improvement of hardness and mechanical properties for seamless steel pipe
Seamless steel pipe are widely used in machinery because the mechanical properties of such steels are very good. However, because it is medium carbon steel, the quenching machine is not good and can be hardened to HRC42-46. If surface hardness is required, and it is desired to reflect the high-quality mechanical function of the seamless steel pipe, the method is to carburize and quench the surface of the seamless steel pipe, so that the required surface hardness can be obtained.
1. After the quenching of the seamless steel pipe, the hardness is greater than HRC55 (up to HRC62) before passing the temper. The highest hardness for practical application is HRC55 (high frequency quenching HRC58).
2. The seamless steel pipe should not be subjected to the heat treatment process of carburizing and quenching.
After quenching and tempering, the parts have good comprehensive mechanical functions and are widely used in various important structural parts, especially connecting rods, bolts, gears and shafts working under alternating load. However, the surface hardness is low, and it is not wear-resistant. The surface hardness of the part can be improved by quenching and tempering + surface hardening.
Carburizing treatment is generally used for heavy-duty parts with surface wear resistance and core impact resistance, and its wear resistance is higher than quenching and tempering + surface quenching. The surface has a carbon content of 0.8-1.2%, and the core is generally 0.1-0.25% (in a special case, 0.35%). After heat treatment, the surface can obtain high hardness (HRC58-62), low core hardness and impact resistance.
If carburizing with a seamless steel pipe, the core will have hard and brittle martensite after quenching, losing the strength of carburizing treatment. Nowadays, the materials used in the carburizing process are not high in carbon content, and the strength of the core to 0.30% can already be reached very high, and it has never appeared in practical applications. The quenching and tempering + high-frequency surface quenching process can be used, but the wear resistance is slightly worse than that of carburizing.
http://www.xysteelpipe.com/info/Improvement-of-hardness-and-mechanical-properties-for-seamless-steel-pipe-1393-1.htm
1. After the quenching of the seamless steel pipe, the hardness is greater than HRC55 (up to HRC62) before passing the temper. The highest hardness for practical application is HRC55 (high frequency quenching HRC58).
2. The seamless steel pipe should not be subjected to the heat treatment process of carburizing and quenching.
After quenching and tempering, the parts have good comprehensive mechanical functions and are widely used in various important structural parts, especially connecting rods, bolts, gears and shafts working under alternating load. However, the surface hardness is low, and it is not wear-resistant. The surface hardness of the part can be improved by quenching and tempering + surface hardening.
Carburizing treatment is generally used for heavy-duty parts with surface wear resistance and core impact resistance, and its wear resistance is higher than quenching and tempering + surface quenching. The surface has a carbon content of 0.8-1.2%, and the core is generally 0.1-0.25% (in a special case, 0.35%). After heat treatment, the surface can obtain high hardness (HRC58-62), low core hardness and impact resistance.
If carburizing with a seamless steel pipe, the core will have hard and brittle martensite after quenching, losing the strength of carburizing treatment. Nowadays, the materials used in the carburizing process are not high in carbon content, and the strength of the core to 0.30% can already be reached very high, and it has never appeared in practical applications. The quenching and tempering + high-frequency surface quenching process can be used, but the wear resistance is slightly worse than that of carburizing.
http://www.xysteelpipe.com/info/Improvement-of-hardness-and-mechanical-properties-for-seamless-steel-pipe-1393-1.htm
2019年5月8日星期三
Advantages and disadvantages of scaffold tube
Several days ago, Prime Steel Pipe shared the brief introduction of scaffolding pipe, I believed that those people who saw that article must have a basic understanding to scaffolding pipe. Today, Prime Steel Pipe will continue to share some information of that, its advantages and disadvantages will be listed below.
Advantages of scaffolding pipe:
1) Bearing capacity is large. When the scaffolding geometry and construction in line with the relevant requirements of the specification, under normal circumstances, the capacity that single tube of scaffolding can bear will reach up to 15kN ~ 35kN (1.5tf ~ 3.5tf, design).
2) Easy assembly and disassembly, erection flexible. As the length of the pipe is easy to adjust, fastener connection is simple, thus it can be adapted to a variety of flat, facade buildings and structures with scaffolding.
3) More economical. Processing is simple, primary investment costs is low; if carefully designing scaffold geometry, paying attention to improve the use of steel pipe turnover, the amount of material can also achieve better economic results. The amount of steel in the building per square meter of fastener steel pipe frame equivalent is about 15 kg.
Disadvantages of scaffolding pipe:
1) Fasteners (especially its screw) are easy to lose;
2) The bar at the node for the eccentric connection, by the anti-slip force transmission load and internal force, thus reducing its carrying capacity;
3) The connection quality of the fastener joint is significantly affected by the quality of the fastener itself and the operation of the worker.
Advantages of scaffolding pipe:
1) Bearing capacity is large. When the scaffolding geometry and construction in line with the relevant requirements of the specification, under normal circumstances, the capacity that single tube of scaffolding can bear will reach up to 15kN ~ 35kN (1.5tf ~ 3.5tf, design).
2) Easy assembly and disassembly, erection flexible. As the length of the pipe is easy to adjust, fastener connection is simple, thus it can be adapted to a variety of flat, facade buildings and structures with scaffolding.
3) More economical. Processing is simple, primary investment costs is low; if carefully designing scaffold geometry, paying attention to improve the use of steel pipe turnover, the amount of material can also achieve better economic results. The amount of steel in the building per square meter of fastener steel pipe frame equivalent is about 15 kg.
Disadvantages of scaffolding pipe:
1) Fasteners (especially its screw) are easy to lose;
2) The bar at the node for the eccentric connection, by the anti-slip force transmission load and internal force, thus reducing its carrying capacity;
3) The connection quality of the fastener joint is significantly affected by the quality of the fastener itself and the operation of the worker.
Welding quality control measures of LSAW steel pipe
Large diameter LSAW steel pipe with its big wall thickness, good material, stable processing technology, becomes the preferred pipe by largest domestic and foreign oil and gas transportation project. In the large diameter LSAW steel pipe welded joints, weld and heat affected zone are the most prone to produce a variety of defects, and welding undercut, pores, slag, not fused, not penetration, welding cracks are the main form of welding defects, and also are the origins those often make LSAW steel pipe produce quality accident. The quality control measures will be listed below, if you you are interested in the production process of LSAW steel pipe, you can click the hyper-link.
1.The quality control before welding:
1) First of all, pipe manufacturer should take control of the quality of raw materials, after passing the inspection, raw materials can formally enter the construction site. And pipe manufacturer resolutely put an end to the use of substandard steel.
2) The next is the management of the welding material. Checking whether the welding material is a qualified product, whether storage and baking system is implemented, whether the surface of the welding material is clean and no rust, and whether the electrode coating is intact, with mildew or not.
3) The next is the welding area cleaning management. Check the cleaning quality of the welding area, there shall not be water, oil, rust and oxide film and other dirt, which plays an important role to prevent the occurrence of external defects in the weld.
4) Finally, choosing the appropriate welding method, it should be implemented before the test welding, after welding principle.
2. The quality control during welding:
1) According to the welding process to review the specifications of the wire and flux is correct or isn't, to prevent the wrong welding wire and flux caused by welding quality accidents.
2) Monitor the welding environment, when the welding environment is not good (temperature below 0 ℃, relative humidity greater than 90%) pipe manufacturer should take appropriate measures after welding.
3) Checkout the groove size, including the gap, blunt edge, angle and wrong, etc. meet the process requirements or not before pre-welding.
4) Checkout the selected welding current, welding voltage, welding speed and other process parameters are correct or aren't in the submerged arc internal and external welding process.
5) Supervise the welding personnel in the submerged arc internal and external welding full use of the length of the pipe end of the arc plate to strengthen the internal and external welding arc plate use efficiency, which helps to improve the quality of pipe end welding.
6) Supervise the welding staff in the welding is the first clean up the slag, whether it has been completely handle joints, groove whether there is oil, rust, slag, water, paint and other dirt.
1.The quality control before welding:
1) First of all, pipe manufacturer should take control of the quality of raw materials, after passing the inspection, raw materials can formally enter the construction site. And pipe manufacturer resolutely put an end to the use of substandard steel.
2) The next is the management of the welding material. Checking whether the welding material is a qualified product, whether storage and baking system is implemented, whether the surface of the welding material is clean and no rust, and whether the electrode coating is intact, with mildew or not.
3) The next is the welding area cleaning management. Check the cleaning quality of the welding area, there shall not be water, oil, rust and oxide film and other dirt, which plays an important role to prevent the occurrence of external defects in the weld.
4) Finally, choosing the appropriate welding method, it should be implemented before the test welding, after welding principle.
2. The quality control during welding:
1) According to the welding process to review the specifications of the wire and flux is correct or isn't, to prevent the wrong welding wire and flux caused by welding quality accidents.
2) Monitor the welding environment, when the welding environment is not good (temperature below 0 ℃, relative humidity greater than 90%) pipe manufacturer should take appropriate measures after welding.
3) Checkout the groove size, including the gap, blunt edge, angle and wrong, etc. meet the process requirements or not before pre-welding.
4) Checkout the selected welding current, welding voltage, welding speed and other process parameters are correct or aren't in the submerged arc internal and external welding process.
5) Supervise the welding personnel in the submerged arc internal and external welding full use of the length of the pipe end of the arc plate to strengthen the internal and external welding arc plate use efficiency, which helps to improve the quality of pipe end welding.
6) Supervise the welding staff in the welding is the first clean up the slag, whether it has been completely handle joints, groove whether there is oil, rust, slag, water, paint and other dirt.
Spiral welded pipe production process
Spiral welded pipe (some people call it SSAW steel pipe) is also a kind of welded pipe, its strength is generally higher than the LSAW steel pipe. Spiral welded pipe with large diameter can be produced by the narrow blank, and SSAW steel pipe with different diameter can also be produced by the same width of blank. However, compared with the same length of the straight pipe, the weld length increased by 30 to 100%, and the production rate is low. Therefore, the smaller diameter of the pipe mostly use LSAW steel pipe, large diameter welded pipe mostly use spiral welded pipe.
The production process of spiral welded pipe
Spiral welded pipe is the steel pipe with spiral seam that using the strip coil as raw material, extrusion forming under normal temperature, and using automatic double wire double-sided submerged arc welding process to weld.
1.Raw materials are coil, wire, flux. Those must finish the rigorous physical and chemical testing before putting into.
2.The head and tail of strip steel butt joint, use single or double wire submerged arc welding, and use automatic submerged arc welding to repair welding after rolled into steel pipe.
3.Before forming, the strip will go through the leveling, cutting edge, planing edge, surface cleaning and delivery to the edge of the treatment.
4.Using electrical contact pressure gauge control the pressure of the cylinder on both sides of the conveyor to ensure the smooth delivery of the strip.
5.Use external control or internal control roll forming.
6.Use weld gap control device to ensure that the weld gap to meet the welding requirements, diameter, misalignment and weld gap are strictly controlled.
7.Welding and external welding all use American Lincoln welding machine to single or double wire submerged arc weld, in order to obtain a stable welding specifications.
8.The welding line after welding must go through on-line continuous ultrasonic automatic injury inspection to ensure that 100% of the spiral weld non-destructive testing coverage. If there are defects, automatic alarm and spray marking, production workers adjust the process parameters at any time, eliminate of defects timely.
9.Use air plasma cutting machine to cut a single pipe.
10.After cutting into a single steel pipe, the first three of each batch of steel pipe must be carried out a strict first inspection system, to check the weld mechanical properties, chemical composition, melting conditions, steel pipe surface quality and after nondestructive testing to ensure that the pipe process qualified, so it can be put into formal production.
11.There are parts marked by ontinuous acoustic flaw on the seam, after manual ultrasound and X-ray review, if there are defects, after repair, again after the nondestructive test until the defect has been confirmed to eliminate.
12.The butt welds and helical welds of strip steel where the junction of the Ding-type joints, all through the X-ray TV or film inspection.
13.Each pipe must go through the hydrostatic test, the pressure using radial seal. Test pressure and time by the steel pipe hydraulic microcomputer detection device strictly controlled. Test parameters are automatically printed.
14.Pipe end machining, so that the vertical face, bevel angle and blunt edge to be accurately controlled.
The production process of spiral welded pipe
Spiral welded pipe is the steel pipe with spiral seam that using the strip coil as raw material, extrusion forming under normal temperature, and using automatic double wire double-sided submerged arc welding process to weld.
1.Raw materials are coil, wire, flux. Those must finish the rigorous physical and chemical testing before putting into.
2.The head and tail of strip steel butt joint, use single or double wire submerged arc welding, and use automatic submerged arc welding to repair welding after rolled into steel pipe.
3.Before forming, the strip will go through the leveling, cutting edge, planing edge, surface cleaning and delivery to the edge of the treatment.
4.Using electrical contact pressure gauge control the pressure of the cylinder on both sides of the conveyor to ensure the smooth delivery of the strip.
5.Use external control or internal control roll forming.
6.Use weld gap control device to ensure that the weld gap to meet the welding requirements, diameter, misalignment and weld gap are strictly controlled.
7.Welding and external welding all use American Lincoln welding machine to single or double wire submerged arc weld, in order to obtain a stable welding specifications.
8.The welding line after welding must go through on-line continuous ultrasonic automatic injury inspection to ensure that 100% of the spiral weld non-destructive testing coverage. If there are defects, automatic alarm and spray marking, production workers adjust the process parameters at any time, eliminate of defects timely.
9.Use air plasma cutting machine to cut a single pipe.
10.After cutting into a single steel pipe, the first three of each batch of steel pipe must be carried out a strict first inspection system, to check the weld mechanical properties, chemical composition, melting conditions, steel pipe surface quality and after nondestructive testing to ensure that the pipe process qualified, so it can be put into formal production.
11.There are parts marked by ontinuous acoustic flaw on the seam, after manual ultrasound and X-ray review, if there are defects, after repair, again after the nondestructive test until the defect has been confirmed to eliminate.
12.The butt welds and helical welds of strip steel where the junction of the Ding-type joints, all through the X-ray TV or film inspection.
13.Each pipe must go through the hydrostatic test, the pressure using radial seal. Test pressure and time by the steel pipe hydraulic microcomputer detection device strictly controlled. Test parameters are automatically printed.
14.Pipe end machining, so that the vertical face, bevel angle and blunt edge to be accurately controlled.
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