Thick-walled lsaw steel pipe anti-rust oil to be disposed of, we must first understand the characteristics and varieties of anti-rust oil, as well as their results. So this time in the procurement of goods can not be thrown off balance, direct save time. Below let us Xiaobian to introduce walled Longitudinal creosote strengths and varieties of it.
1. Quick-drying
Its biggest advantage of doing that is fast, rugged, use widely anticipated, it is possible to use in harsh environments, the use.
2. Soft membrane
With paraffin oil or heavy oil disposal made, rust-proof function are the three strongest presence, and can be washed using one kind of solvent.
3. Film type
Its anti-rust function relatively handicap. But its operation is very simple disposal. Use can reduce the harm caused by their conflict, reduce costs, ensure productivity directly carried out.
2018年5月29日星期二
Thermal Deformation Method of LSAW Steel Pipe
First, reasonable selection. Precision messy mold material should choose a good micro-deformation of steel on steel carbide segregation serious mold should be a reasonable casting and heat treatment quenching and tempering, solution heat treatment on a large double refining and casting mold steel can not be carried out. Reasonable choice of heating temperature control heating rate, on messy precision molds can be heated slowly, preheating and other methods to reduce the mold uniform heating heat deformation
Second, the correct operation of the heat treatment process and reasonable heat treatment process is also a useful way to reduce messy precision mold deformation. Deformation reason messy precision molds are often messy, but we only need to master the rules of the deformation, to analyze the attack reason, the choice of methods to avoid abnormal deformation of the mold can be reduced, and also can be controlled.
Third, precision molds to be messy pre-heat treatment, machining process to eliminate the remaining episodes of stress. Precision messy mold, when conditions allow, try to use cryogenic vacuum heating process and hardening after quenching. Mold hardness in ensuring the premise, try to use pre-cooling, grading cooling or quenching temperature quenching process.
Fourth, mold planning is depicted to be reasonable, not too poor thickness, shape to be symmetrical with respect to large deformation mold deformation to master the rules, set aside allowance, on large, sophisticated planning messy mold can be used in combination. For some messy precision molds can be used pre-heat treatment, aging heat treatment, quenching and nitriding to control the accuracy of the mold. When mold repair blisters, porosity, wear and other defects, selection of cold welding and other small heat-affected patch repair equipment, to prevent deformation during the attack.
Second, the correct operation of the heat treatment process and reasonable heat treatment process is also a useful way to reduce messy precision mold deformation. Deformation reason messy precision molds are often messy, but we only need to master the rules of the deformation, to analyze the attack reason, the choice of methods to avoid abnormal deformation of the mold can be reduced, and also can be controlled.
Third, precision molds to be messy pre-heat treatment, machining process to eliminate the remaining episodes of stress. Precision messy mold, when conditions allow, try to use cryogenic vacuum heating process and hardening after quenching. Mold hardness in ensuring the premise, try to use pre-cooling, grading cooling or quenching temperature quenching process.
Fourth, mold planning is depicted to be reasonable, not too poor thickness, shape to be symmetrical with respect to large deformation mold deformation to master the rules, set aside allowance, on large, sophisticated planning messy mold can be used in combination. For some messy precision molds can be used pre-heat treatment, aging heat treatment, quenching and nitriding to control the accuracy of the mold. When mold repair blisters, porosity, wear and other defects, selection of cold welding and other small heat-affected patch repair equipment, to prevent deformation during the attack.
How to Improve the Performance Characteristics of the Oil Casing
Oil casing surface less oxidation and decarburization induction heating quenching steel surface decarburization phenomenon are not found in metallographic observation, whereas conventional heating M0.10mm low carbon layer present on the surface after solution treatment. Oil casing oxidation amount after solution treatment, friction material surface after conventional heating solution scale, low yield. ~ 0 0.15% 20%; induction oxide Wu is not only significantly dense oxide film. Mechanical properties of steel at room temperature gives the EAF steel smelting and vacuum sense, using different methods of heating the solution treatment, but also by the mechanical properties at room temperature after the same side effect of treatment comparison.
Data showed that dissolved after two days aging treatment inch mechanical properties at the same level. However, induction heating the steel to the amount of EAF, casing metallurgical quality far below the vacuum induction furnace steel. This induction heating solution treatment to make up the gap of steel, showing the advantages of induction heating solution at the spoon.
Data showed that dissolved after two days aging treatment inch mechanical properties at the same level. However, induction heating the steel to the amount of EAF, casing metallurgical quality far below the vacuum induction furnace steel. This induction heating solution treatment to make up the gap of steel, showing the advantages of induction heating solution at the spoon.
Causes of surface cracking of spiral steel are analyzed
Generally speaking, hydraulic (pneumatic) part in planning the use of mechanical performance, data are assumed to be uniform, successive, isotropic, according to the analysis of this approach is safe and that the plan will sometimes spiral steel pipe unexpected trouble cracking attack.
Study found that the use of brittle cracking and also member of the relevant temperature. After discussions we found that when the temperature drops below a certain temperature, brittle materials will change the situation, the impact absorbed energy decreased, this representation is called cold crisp, high-strength metal resources guessed low stress brittle episodes cracking process, the data arrangement is far from uniform, isotropic. Arrangements have cracks, there will be inclusions, porosity and other drawbacks can be funded look into guessed microcracks. Therefore, even when the program based on the operating temperature of the member to choose a suitable cold brittle temperature change information.
Spiral pipe frequency and circuit capacitance, inductance is inversely proportional to the square root, perhaps proportional to the square root of voltage, current, just change the circuit capacitance, inductance, or voltage, you can change the size of the current frequency, and then arrived at the welding temperature control intention. On low-carbon steel welding temperature control in the 1250 ~ 1460 ℃, can meet the pipe wall thickness 3 ~ 5mm penetration requirements. In addition, the welding temperature welding speed can also go through the scheduling to end.
When the spiral steel pipe cold drawn, hot rolled tube cracks and other shortcomings or high-precision drawing fuel tank is made after cracking in the process of applying attack, almost no plastic deformation episodes are usually brittle cracking. Brittle cracking is a result of a variety of reasons. Such as: the separation of the grain boundary thereof, regardless of their strength is stronger than the matrix strength or weak, are all reasons for the onset of cracks; the grain boundary segregation of inclusions is cracking reason; the other, even in far less than the yield limit alternating loading, will also cause the onset of fatigue crack appearance.
Spiral Pipe welding temperature affected the primary frequency eddy current heating power, the impact of high frequency eddy current thermal power by the primary current frequency, the eddy current heating power and current proportional to the square of the frequency of agitation; and the current frequency of agitation by agitation and voltage, current and capacitance , inductance effects.
When the lack of spiral steel pipe heat input, the weld edge is heated up to a temperature of less than weld metal arrangements still adhere to solid form incomplete fusion or penetration; when the lack of heat input, the weld edge is heated beyond the soldering temperature seizures burnt or droplet weld constitute Cave.
Study found that the use of brittle cracking and also member of the relevant temperature. After discussions we found that when the temperature drops below a certain temperature, brittle materials will change the situation, the impact absorbed energy decreased, this representation is called cold crisp, high-strength metal resources guessed low stress brittle episodes cracking process, the data arrangement is far from uniform, isotropic. Arrangements have cracks, there will be inclusions, porosity and other drawbacks can be funded look into guessed microcracks. Therefore, even when the program based on the operating temperature of the member to choose a suitable cold brittle temperature change information.
Spiral pipe frequency and circuit capacitance, inductance is inversely proportional to the square root, perhaps proportional to the square root of voltage, current, just change the circuit capacitance, inductance, or voltage, you can change the size of the current frequency, and then arrived at the welding temperature control intention. On low-carbon steel welding temperature control in the 1250 ~ 1460 ℃, can meet the pipe wall thickness 3 ~ 5mm penetration requirements. In addition, the welding temperature welding speed can also go through the scheduling to end.
When the spiral steel pipe cold drawn, hot rolled tube cracks and other shortcomings or high-precision drawing fuel tank is made after cracking in the process of applying attack, almost no plastic deformation episodes are usually brittle cracking. Brittle cracking is a result of a variety of reasons. Such as: the separation of the grain boundary thereof, regardless of their strength is stronger than the matrix strength or weak, are all reasons for the onset of cracks; the grain boundary segregation of inclusions is cracking reason; the other, even in far less than the yield limit alternating loading, will also cause the onset of fatigue crack appearance.
Spiral Pipe welding temperature affected the primary frequency eddy current heating power, the impact of high frequency eddy current thermal power by the primary current frequency, the eddy current heating power and current proportional to the square of the frequency of agitation; and the current frequency of agitation by agitation and voltage, current and capacitance , inductance effects.
When the lack of spiral steel pipe heat input, the weld edge is heated up to a temperature of less than weld metal arrangements still adhere to solid form incomplete fusion or penetration; when the lack of heat input, the weld edge is heated beyond the soldering temperature seizures burnt or droplet weld constitute Cave.
Spiral Welded Pipe Production and Use
SSAW steel pipe often there will be some quality problems in the production and use, affecting normal use in some aspects, the need for spiral welded pipe to identify the quality, according to a certain way and performance testing, can produce significant in actual use role, then how to identify counterfeit spiral welded pipe method: the appearance often pockmarked face phenomenon. Generally the whole proportionate amount would be better, mainly taking into account the cumulative error and probability theory this problem. Some of the above please add if inadequate, we welcome the discussion of knowledge about aspects of the steel pipe together, advances constantly exchange. Pock is due to badly worn groove spiral welded pipe surface irregularities caused by uneven defects. Because of shoddy spiral welded pipe manufacturers have to pursue profits, rolling groove most often exceeded. The surface is easy to produce scarring.
Quality spiral welded pipe of uniform composition. High tonnage cold shear machine, cutting head end surface smooth and tidy, and shoddy materials due to the poor material, cut the first end surface there are often off the meat of the phenomenon that is uneven, and no metallic luster. And because of shoddy materials manufacturers cutting products less head, head and tail will be a big ears. Diameter size fluctuations. Folding is formed on the surface of a variety of spiral welded pipe polyline, this defect is often longitudinally throughout the entire product. Causes folding due to shoddy manufacturers to pursue high efficiency, reduction is too large, resulting in the ears, generated under a rolling folding, the product will crack when folded bending, strength thick spiral welded large decline. Easily scratched.
The reason is shoddy material manufacturers poorly equipped, easy to produce burr, scratching the surface of the spiral welded pipe. Depth scratch reduce the intensity of seamless steel pipe. Prone to folding. Transverse ribs thin and low. Often sufficient dissatisfaction with the phenomenon, because manufacturers to achieve large negative tolerance, finished before the reduction of a few relatively large, iron-type small, pass sufficient dissatisfaction. Easy to crack. The reason is that it is blank adobe, adobe many pores, adobe in the cooling process due to thermal stress, cracks, after after rolling there crack.
Quality spiral welded pipe of uniform composition. High tonnage cold shear machine, cutting head end surface smooth and tidy, and shoddy materials due to the poor material, cut the first end surface there are often off the meat of the phenomenon that is uneven, and no metallic luster. And because of shoddy materials manufacturers cutting products less head, head and tail will be a big ears. Diameter size fluctuations. Folding is formed on the surface of a variety of spiral welded pipe polyline, this defect is often longitudinally throughout the entire product. Causes folding due to shoddy manufacturers to pursue high efficiency, reduction is too large, resulting in the ears, generated under a rolling folding, the product will crack when folded bending, strength thick spiral welded large decline. Easily scratched.
The reason is shoddy material manufacturers poorly equipped, easy to produce burr, scratching the surface of the spiral welded pipe. Depth scratch reduce the intensity of seamless steel pipe. Prone to folding. Transverse ribs thin and low. Often sufficient dissatisfaction with the phenomenon, because manufacturers to achieve large negative tolerance, finished before the reduction of a few relatively large, iron-type small, pass sufficient dissatisfaction. Easy to crack. The reason is that it is blank adobe, adobe many pores, adobe in the cooling process due to thermal stress, cracks, after after rolling there crack.
How to check the quality of spiral steel tube
Spiral pipe factory should be done before the mechanical performance test and flattening test, and flaring test, and to achieve the standard requirements. Spiral steel pipe quality inspection method is as follows:
1, From the face of it, that is visual inspection. Visual inspection of welded joints is a simple procedure but widely used test method is an important part of product testing, the main defects and deviations are found on the surface of the weld size. Usually by the naked eye, with the standard model, gauge and test tools such as a magnifying glass. If the weld surface defects, weld defects there may be internal.
2, Physical test methods: physical test method is to use some physical phenomena assay or test method. Or within the workpiece material defect inspection, and are generally used NDT methods. NDT ultrasonic flaw detection, radiation detection, penetration testing, magnetic testing and so on.
3, Pressure vessels strength test: pressure vessels, in addition to tightness test, but also the strength test. There are common test of two hydraulic test and air pressure. They can be tested in working under pressure vessels and piping welds compactness. Hydrostatic pressure test is more sensitive than the test speed and, at the same time after the test products do not waste water treatment, drainage problems for the product is particularly applicable. But the risk is greater than the test pressure test. When tested, it must comply with the appropriate safety measures to prevent accidents during the test.
4, Compact test: liquid or gas storage vessel welding, which is not dense weld defects, such as penetrating cracks, pores, slag, incomplete penetration loose tissue and the like, can be used to find the density test. Compactness test methods are: kerosene test, carrying water testing, water will test.
5, The hydrostatic test should be done each pipe hydrostatic test without leakage, pressure test press Calculate P = 2ST / D where S- hydrostatic test stress test Mpa, hydrostatic test stress test according to the corresponding steel standard specifies the minimum degree of yield (Q235 is 235Mpa) 60% of the selection. Regulators time: D <508 test pressure holding time less than 5 seconds; D≥508 test pressure holding time less than 10 seconds 4, non-destructive testing of steel welding seam, strip end weld and circumferential joints should X-ray or ultrasonic inspection. For ordinary combustible fluid transport spiral steel to weld should be 100% SX-ray or ultrasound test, used for water, sewage, air, heating steam and other general transmission fluid with spiral weld steel pipe should be X-rays or ultrasonic inspection checks (20%).
The spiral steel pipe quality test results, spiral pipe usually divided into three categories: Qualified, rework and scrap. Qualified means the quality and appearance of the intrinsic quality to meet the standards or technical delivery and acceptance conditions spiral steel pipe; rework refers to the quality and appearance of the intrinsic quality does not fully comply with the acceptance criteria and strip body, but allow the repair after repair can meet the standards and acceptance conditions spiral pipe; waste refers to substandard quality and appearance of the intrinsic quality of spiral steel still not up to standard and acceptance conditions do not allow repair or rework later.
1, From the face of it, that is visual inspection. Visual inspection of welded joints is a simple procedure but widely used test method is an important part of product testing, the main defects and deviations are found on the surface of the weld size. Usually by the naked eye, with the standard model, gauge and test tools such as a magnifying glass. If the weld surface defects, weld defects there may be internal.
2, Physical test methods: physical test method is to use some physical phenomena assay or test method. Or within the workpiece material defect inspection, and are generally used NDT methods. NDT ultrasonic flaw detection, radiation detection, penetration testing, magnetic testing and so on.
3, Pressure vessels strength test: pressure vessels, in addition to tightness test, but also the strength test. There are common test of two hydraulic test and air pressure. They can be tested in working under pressure vessels and piping welds compactness. Hydrostatic pressure test is more sensitive than the test speed and, at the same time after the test products do not waste water treatment, drainage problems for the product is particularly applicable. But the risk is greater than the test pressure test. When tested, it must comply with the appropriate safety measures to prevent accidents during the test.
4, Compact test: liquid or gas storage vessel welding, which is not dense weld defects, such as penetrating cracks, pores, slag, incomplete penetration loose tissue and the like, can be used to find the density test. Compactness test methods are: kerosene test, carrying water testing, water will test.
5, The hydrostatic test should be done each pipe hydrostatic test without leakage, pressure test press Calculate P = 2ST / D where S- hydrostatic test stress test Mpa, hydrostatic test stress test according to the corresponding steel standard specifies the minimum degree of yield (Q235 is 235Mpa) 60% of the selection. Regulators time: D <508 test pressure holding time less than 5 seconds; D≥508 test pressure holding time less than 10 seconds 4, non-destructive testing of steel welding seam, strip end weld and circumferential joints should X-ray or ultrasonic inspection. For ordinary combustible fluid transport spiral steel to weld should be 100% SX-ray or ultrasound test, used for water, sewage, air, heating steam and other general transmission fluid with spiral weld steel pipe should be X-rays or ultrasonic inspection checks (20%).
The spiral steel pipe quality test results, spiral pipe usually divided into three categories: Qualified, rework and scrap. Qualified means the quality and appearance of the intrinsic quality to meet the standards or technical delivery and acceptance conditions spiral steel pipe; rework refers to the quality and appearance of the intrinsic quality does not fully comply with the acceptance criteria and strip body, but allow the repair after repair can meet the standards and acceptance conditions spiral pipe; waste refers to substandard quality and appearance of the intrinsic quality of spiral steel still not up to standard and acceptance conditions do not allow repair or rework later.
Measures on production line for casing pipe
In order to maintain a heat-treated product with stable performance during the rapid heat treatment of induction heating, the following measures should be taken on the production line:
(1) The casing pipe plant uses continuous heating steel bridging technology to apply bridging technology to improve the phenomenon of low steel temperature and increase the steel product yield. The use of computers to control the head and tail of steel technology; the use of dual-frequency power to control the temperature of the end of the steel pipe; the use of rotating joints to achieve a great advance, etc. to improve the longitudinal temperature uniformity of the steel.
(2) Advanced steel conveyors are used to ensure uniform steel speeds, and steel tubes and large-size bars should rotate at a constant speed. The transmission mechanism should use variable frequency drive to improve the stability and reliability of the mechanism. This is one of the important conditions for assuring that the longitudinal temperature of the phased material is uniform during rapid heating.
(3) The use of advanced and reliable heating temperature control system temperature and power closed-loop home-made system is currently the best temperature control system. The control content of the oil casing manufacturer includes elements related to heating temperature such as power and steel speed, which can accurately control the level reached by the heating temperature.
http://www.xysteelpipe.com/info/Measures-on-production-line-for-casing-pipe-1100-1.htm
(1) The casing pipe plant uses continuous heating steel bridging technology to apply bridging technology to improve the phenomenon of low steel temperature and increase the steel product yield. The use of computers to control the head and tail of steel technology; the use of dual-frequency power to control the temperature of the end of the steel pipe; the use of rotating joints to achieve a great advance, etc. to improve the longitudinal temperature uniformity of the steel.
(2) Advanced steel conveyors are used to ensure uniform steel speeds, and steel tubes and large-size bars should rotate at a constant speed. The transmission mechanism should use variable frequency drive to improve the stability and reliability of the mechanism. This is one of the important conditions for assuring that the longitudinal temperature of the phased material is uniform during rapid heating.
(3) The use of advanced and reliable heating temperature control system temperature and power closed-loop home-made system is currently the best temperature control system. The control content of the oil casing manufacturer includes elements related to heating temperature such as power and steel speed, which can accurately control the level reached by the heating temperature.
http://www.xysteelpipe.com/info/Measures-on-production-line-for-casing-pipe-1100-1.htm
2018年5月28日星期一
Tress of API 5CT Oil Casing in Oil Well
The stress on the API 5CT oil casing in the oil well: to ensure that the casing running into the well is continuous, not cracked or deformed, the casing is required to have a certain strength, enough to resist the external force it receives. Therefore, it is necessary to analyze the stress on the inner well casing.
1) Pulling force
2) Extrusion force
3) Internal pressure
4) Bending force
In conclusion, the casing in the well mainly bears the first three forces. The stress conditions of the various parts are different, the upper part receives the pulling force, the lower part has the outer pressing force, and the middle part receives less external force. When designing the casing string, the steel grade and wall thickness of the casing are selected based on the above consideration of the safety factor. For the API standard casing, the general safety factor for tensile is 1.6-2.0, the safety factor for impact resistance is 1.00-1.50, generally 1.125, the safety factor for internal pressure is 1.0-1.33, and the safety factor for the compression resistance at the cement injection site is The desirable value is 0.85. It should be emphasized that the safety factor in the design of casing string strength is carefully selected according to the region, stratum and the later oil extraction and gas production process. He is an empirical figure. Due to the different external forces applied to the upper, middle and lower parts of the casing string, the designed casing string is often thicker or more steel grades in the upper and lower walls, and opposite in the middle, so it is necessary to number the casing. Into this well. In most cases, the casing is working in corrosive media. Therefore, in addition to requiring a certain degree of joint strength, the casing is required to have good sealing performance and to be resistant to corrosion.
http://www.xysteelpipe.com/info/Tress-of-API-5CT-Oil-Casing-in-Oil-Well-1101-1.htm
1) Pulling force
2) Extrusion force
3) Internal pressure
4) Bending force
In conclusion, the casing in the well mainly bears the first three forces. The stress conditions of the various parts are different, the upper part receives the pulling force, the lower part has the outer pressing force, and the middle part receives less external force. When designing the casing string, the steel grade and wall thickness of the casing are selected based on the above consideration of the safety factor. For the API standard casing, the general safety factor for tensile is 1.6-2.0, the safety factor for impact resistance is 1.00-1.50, generally 1.125, the safety factor for internal pressure is 1.0-1.33, and the safety factor for the compression resistance at the cement injection site is The desirable value is 0.85. It should be emphasized that the safety factor in the design of casing string strength is carefully selected according to the region, stratum and the later oil extraction and gas production process. He is an empirical figure. Due to the different external forces applied to the upper, middle and lower parts of the casing string, the designed casing string is often thicker or more steel grades in the upper and lower walls, and opposite in the middle, so it is necessary to number the casing. Into this well. In most cases, the casing is working in corrosive media. Therefore, in addition to requiring a certain degree of joint strength, the casing is required to have good sealing performance and to be resistant to corrosion.
http://www.xysteelpipe.com/info/Tress-of-API-5CT-Oil-Casing-in-Oil-Well-1101-1.htm
Process of making Tpes and stainless steel tubes
Manufacturing types and processes of stainless steel pipe
1. Seamless Hot Rolling Processes
Round Pipe Billet → Heating → Perforation → Three Roll Skew Rolling, Continuous Rolling or Extrusion → Off Pipe → Sizing (Or Reducing Diameter)→ Cooling → Billet → Straightening → Water Pressure Test ( Or Flaw Detection) → Marking → Storage
2. Seamless Cold Rolling (Cold drawn) Processes
Round Pipe Billet → Heating → Perforation → Head → Annealing → Pickling → Oil (Copper) → Multi Pass Drawing (Cold Rolling) → Billet → Heat Treatment → Straightening → Water Pressure Test → Marking → Storage
3. Longitudinal welding (Straight seam welding) processes
Including ERW, EFW.
http://www.xysteelpipe.com/info/Process-of-making-Tpes-and-stainless-steel-tubes-1102-1.htm
1. Seamless Hot Rolling Processes
Round Pipe Billet → Heating → Perforation → Three Roll Skew Rolling, Continuous Rolling or Extrusion → Off Pipe → Sizing (Or Reducing Diameter)→ Cooling → Billet → Straightening → Water Pressure Test ( Or Flaw Detection) → Marking → Storage
2. Seamless Cold Rolling (Cold drawn) Processes
Round Pipe Billet → Heating → Perforation → Head → Annealing → Pickling → Oil (Copper) → Multi Pass Drawing (Cold Rolling) → Billet → Heat Treatment → Straightening → Water Pressure Test → Marking → Storage
3. Longitudinal welding (Straight seam welding) processes
Including ERW, EFW.
http://www.xysteelpipe.com/info/Process-of-making-Tpes-and-stainless-steel-tubes-1102-1.htm
Dimensions Tolerance for API 5L Seamless Pipe
Dimensions tolerance for API 5L seamless pipe.
1. For outer diameters less than 2 3/8 in (60.3 mm), pipe body diameter tolerance +/-0.5 mm. Pipe end +/- 0.5 mm; Out of Roundness tolerance for pipe body is 0.9 mm (0.036 in), pipe end 0.6 mm (0.024 mm).
2. For OD equal or above 2 3/8 in (60.3) to 24 in (610 mm), (diameter tolerance) for pipe body is +/- 0.0075D, pipe end +/- 0.005D but max to +/- 1.6 mm (0.063mm); Roundness tolerance for pipe body ≤ 0.015D, pipe end ≤ 0.01D.
(In case agreed with manufacturer and client, more strictly tolerances could be applied)
3. For wall thickness
Below than 4 mm (0.0157 in), tolerance +0.6 (0.024 mm), -0.5 mm (0.020 in);
For API 5L seamless steel pipe thickness in 4 mm to 10 mm (0.394 in), +0.150t, -0.125t;
For API seamless pipe thickness 10 mm to 25mm (0.984 in), +/-0.125t;
Wall thickness ≥ 25 mm, +3.7mm or +0.1t (if larger) and -3.0 mm (0.120 in) or -0.1t (if larger).
t for thickness;
4. For straightness, max for full length, tolerance maximum 0.15% of length.
5. Straightness, max deviation for pipe end, shall be ≤ 0.3 mm /m.
6. Length +/- 200 mm for general, +/- 25.4 mm for special.
http://www.xysteelpipe.com/info/Dimensions-Tolerance-for-API-5L-Seamless-Pipe-1097-1.htm
1. For outer diameters less than 2 3/8 in (60.3 mm), pipe body diameter tolerance +/-0.5 mm. Pipe end +/- 0.5 mm; Out of Roundness tolerance for pipe body is 0.9 mm (0.036 in), pipe end 0.6 mm (0.024 mm).
2. For OD equal or above 2 3/8 in (60.3) to 24 in (610 mm), (diameter tolerance) for pipe body is +/- 0.0075D, pipe end +/- 0.005D but max to +/- 1.6 mm (0.063mm); Roundness tolerance for pipe body ≤ 0.015D, pipe end ≤ 0.01D.
(In case agreed with manufacturer and client, more strictly tolerances could be applied)
3. For wall thickness
Below than 4 mm (0.0157 in), tolerance +0.6 (0.024 mm), -0.5 mm (0.020 in);
For API 5L seamless steel pipe thickness in 4 mm to 10 mm (0.394 in), +0.150t, -0.125t;
For API seamless pipe thickness 10 mm to 25mm (0.984 in), +/-0.125t;
Wall thickness ≥ 25 mm, +3.7mm or +0.1t (if larger) and -3.0 mm (0.120 in) or -0.1t (if larger).
t for thickness;
4. For straightness, max for full length, tolerance maximum 0.15% of length.
5. Straightness, max deviation for pipe end, shall be ≤ 0.3 mm /m.
6. Length +/- 200 mm for general, +/- 25.4 mm for special.
http://www.xysteelpipe.com/info/Dimensions-Tolerance-for-API-5L-Seamless-Pipe-1097-1.htm
2018年5月18日星期五
How to distinguish between SMLS pipes and ordinary steel pipes
Ordinary steel pipes, such as water pipes, are usually welded through a curved steel plate, and then a weld can be found; the coarser diameter is usually a spiral weld.
SMLS pipes are usually molten steel which is formed by the process of backfilling and stretching after ring gap slit, so there is no weld. In terms of performance, especially the pressure capacity is much higher than that of ordinary steel pipe, so it is often used in high voltage equipment.
Such as the pipe connection of the hydraulic equipment. The weak links and the weld quality are the main factors affecting the overall performance of the common steel pipe weld. People living in the North usually have water pipes or heating pipes, which are frozen and exploded in winter. The pipe is not a SMLS pipe. Ordinary steel pipes, such as water pipes, are usually welded through a curved steel plate, and then a weld can be found; the coarser diameter is usually a spiral weld.
SMLS pipes are usually molten steel which is formed by the process of backfilling and stretching after ring gap slit, so there is no weld. In terms of performance, especially the pressure capacity is much higher than that of ordinary steel pipe, so it is often used in high voltage equipment.
Such as the pipe connection of the hydraulic equipment. The weak links and the weld quality are the main factors affecting the overall performance of the common steel pipe weld. People living in the North usually have water pipes or heating pipes, which are frozen and exploded in winter. The pipe is not a SMLS pipe. Ordinary steel pipes, such as water pipes, are usually welded through a curved steel plate, and then a weld can be found; the coarser diameter is usually a spiral weld.
Pay attention to buying SMLS pipes
1. Material problem of SMLS pipe material
Many companies use more materials and materials, usually referring to the amount of nickel. Although it can be used to distinguish medicine, it is obvious that this is a misunderstanding, because small charge can only be identified by more than 7 nickel. But the price difference between raw materials is very large. This is one of the fake products. In particular, 321 of high nickel and 316 of high nickel forgery are very serious.
2. SMLS pipe size problem
Many customers have basically no technical support for testing. For example, 90 degree elbow, the traditional is R = 1.5 D, but the Wenzhou market is basically more than 1.25D mold production, do not underestimate the weight of the 0.25D~~ inside, but the difference is very big. This is the so-called factory standard, far below the standard.
3. The thickness of SMLS pipe material
Of course, now the customer is very smart, will use a caliper to measure the thickness, although sometimes the customer feels reluctant to observe, but neglects a little, that is to say, the thickness of the back arc is not enough! Because the elbow pushing process will be cut off, so the caliber is barely observed.
4. SMLS pipe sand treatment and sandblasting treatment and NDT
Many manufacturers do not carry out solution treatment and 100% osmosis nondestructive testing in the market. This also has a large amount of sand blasting instead of sand, which saves these steps and greatly reduces the cost.
5. Seamless welding
Welding seamless, is to do welding elbow, after grinding and acid washing after the sand, there is no sign of the surface of the welding, even the use of advanced testing equipment can not see it is the welding elbow.
6. Spot welding and repair welding
The elbow pushing process will become thinner, so in general, manufacturers will use thicker pipes. If you use thin raw materials, it is definitely not qualified. Under normal circumstances, the filament is about 40, which is much lower than the standard if the process is poor or the drawing tube is used.
Many companies use more materials and materials, usually referring to the amount of nickel. Although it can be used to distinguish medicine, it is obvious that this is a misunderstanding, because small charge can only be identified by more than 7 nickel. But the price difference between raw materials is very large. This is one of the fake products. In particular, 321 of high nickel and 316 of high nickel forgery are very serious.
2. SMLS pipe size problem
Many customers have basically no technical support for testing. For example, 90 degree elbow, the traditional is R = 1.5 D, but the Wenzhou market is basically more than 1.25D mold production, do not underestimate the weight of the 0.25D~~ inside, but the difference is very big. This is the so-called factory standard, far below the standard.
3. The thickness of SMLS pipe material
Of course, now the customer is very smart, will use a caliper to measure the thickness, although sometimes the customer feels reluctant to observe, but neglects a little, that is to say, the thickness of the back arc is not enough! Because the elbow pushing process will be cut off, so the caliber is barely observed.
4. SMLS pipe sand treatment and sandblasting treatment and NDT
Many manufacturers do not carry out solution treatment and 100% osmosis nondestructive testing in the market. This also has a large amount of sand blasting instead of sand, which saves these steps and greatly reduces the cost.
5. Seamless welding
Welding seamless, is to do welding elbow, after grinding and acid washing after the sand, there is no sign of the surface of the welding, even the use of advanced testing equipment can not see it is the welding elbow.
6. Spot welding and repair welding
The elbow pushing process will become thinner, so in general, manufacturers will use thicker pipes. If you use thin raw materials, it is definitely not qualified. Under normal circumstances, the filament is about 40, which is much lower than the standard if the process is poor or the drawing tube is used.
Analysis of SMLS pipeline defects
The hot rolled Smls pipe is defined as a spiral, half spiral or irregular toothed fold in the inner surface of the steel tube, and some of them are linear Alice skins. The head of the steel pipe has internal fracture, some of which exist in the whole steel pipe, or regular or irregular. Defective steel pipes can be grinded and broken down after being broken. Internal defects have always been one of the main reasons that affect the production and output indexes of steel pipes. There are two main reasons for internal defects: continuous casting billet quality (internal) and perforating process system (external factors).
Analysis of the causes of internal folding
When the steel pipe is pierced by inclined rolling, the continuous casting of the core is subjected to tensile stress, so it is easy to break the metal center and form holes. The metal surface of the cavity is rough and quickly oxidizes the head of the cooling water and air, forming a crease attached to the inner surface of the pipe during the subsequent rolling process. Therefore, to eliminate internal defects, we must avoid loopholes.
The relationship between the quality of continuous casting billet and the defect of steel tube
In the case of continuous casting tube, if there is no folding, no internal and external surface cracks and capillary delamination, a qualified product tube can be produced in general. Therefore, smelting process is the key to producing qualified steel pipe. In recent years, experts and scholars have produced defects through experimental analysis, including central loosening, core shrinkage and columnar crystals in the depth of continuous casting.
The relationship between the perforation process system and the internal defects
The deformation of cross rolling piercing includes basic deformation and additional deformation. The matrix deformation means that when the solid CCM blank enters the capillary, the geometric size and size of the rolling are visual deformation, and the geometric size, shape and material of the deformation have nothing to do with the rolling.
The additional deformation is due to the uneven deformation of the metal produced in the body, mainly including torsional deformation, longitudinal shear deformation and tangential shear deformation. This deformation will reduce product quality and increase energy consumption, so this harmful deformation should be minimized in production. Any factors that reduce the plastic and brittle fracture strength of the continuous casting tube or increase the lateral tensile force of the continuous casting tube will result in the formation of internal fracture, and the internal fracture is mainly produced in the process of perforation, but the specific reasons are varied.
Analysis of the causes of internal folding
When the steel pipe is pierced by inclined rolling, the continuous casting of the core is subjected to tensile stress, so it is easy to break the metal center and form holes. The metal surface of the cavity is rough and quickly oxidizes the head of the cooling water and air, forming a crease attached to the inner surface of the pipe during the subsequent rolling process. Therefore, to eliminate internal defects, we must avoid loopholes.
The relationship between the quality of continuous casting billet and the defect of steel tube
In the case of continuous casting tube, if there is no folding, no internal and external surface cracks and capillary delamination, a qualified product tube can be produced in general. Therefore, smelting process is the key to producing qualified steel pipe. In recent years, experts and scholars have produced defects through experimental analysis, including central loosening, core shrinkage and columnar crystals in the depth of continuous casting.
The relationship between the perforation process system and the internal defects
The deformation of cross rolling piercing includes basic deformation and additional deformation. The matrix deformation means that when the solid CCM blank enters the capillary, the geometric size and size of the rolling are visual deformation, and the geometric size, shape and material of the deformation have nothing to do with the rolling.
The additional deformation is due to the uneven deformation of the metal produced in the body, mainly including torsional deformation, longitudinal shear deformation and tangential shear deformation. This deformation will reduce product quality and increase energy consumption, so this harmful deformation should be minimized in production. Any factors that reduce the plastic and brittle fracture strength of the continuous casting tube or increase the lateral tensile force of the continuous casting tube will result in the formation of internal fracture, and the internal fracture is mainly produced in the process of perforation, but the specific reasons are varied.
Seamless steel tube is classified by section shape
Seamless steel pipe products and specifications are very numerous, and their performance requirements are various. All of these should be distinguished according to user requirements or changes in working conditions. In general, SMLS pipe products should be based on cross section shape, production method, material quality, connection mode, plating characteristics and classification.
The cross-section shape of SMLS pipe can be divided into round steel pipe and special-shaped steel tube.
The special-shaped steel pipe is a kind of steel pipe with various non circular sections. There are: square tube, square tube, elliptical tube, flat tube, semicircle tube, six corner tube, six corner tube, one side six corner tube, equilateral triangle tube, five corner flower tube, octagonal tube, convex tube, double convex tube. Double tube, multi concave tube, melon tube, flat tube, diamond tube, star tube, parallel quadrilateral tube, ribbed tube, drip tube, inner fin tube, stranded tube, tube and multi-layer tube.
SMLS pipes are divided into section steel and cross section steel according to their longitudinal profile.
SMLS pipes refer to the cross section shape, inner and outer diameters and wall thickness of pipes along the length, such as periodic or non periodic changes of steel pipes. They are: conical tube, tapered tube, trapezoidal tube, trapezoidal tube, circulating pipe, bellows, radiator tube and double barrel.
The cross-section shape of SMLS pipe can be divided into round steel pipe and special-shaped steel tube.
The special-shaped steel pipe is a kind of steel pipe with various non circular sections. There are: square tube, square tube, elliptical tube, flat tube, semicircle tube, six corner tube, six corner tube, one side six corner tube, equilateral triangle tube, five corner flower tube, octagonal tube, convex tube, double convex tube. Double tube, multi concave tube, melon tube, flat tube, diamond tube, star tube, parallel quadrilateral tube, ribbed tube, drip tube, inner fin tube, stranded tube, tube and multi-layer tube.
SMLS pipes are divided into section steel and cross section steel according to their longitudinal profile.
SMLS pipes refer to the cross section shape, inner and outer diameters and wall thickness of pipes along the length, such as periodic or non periodic changes of steel pipes. They are: conical tube, tapered tube, trapezoidal tube, trapezoidal tube, circulating pipe, bellows, radiator tube and double barrel.
Seamless tube production line cooling bed type
The cooling bed of seamless pipe production line has single chain cooling bed, double chain cooling bed, new chain cooling bed, step cooling bed and spiral cooling bed.
1, double strand cold bed
The dual cooling bed includes a forward transport chain and a reverse transport chain, each transmission chain with a transmission system. The steel pipe is placed between the two lines of the forward transport chain, and the reverse chain carries the weight of the pipe body. The double bed cooling bed pushes the steel pipe forward with the thrust of the forward transport chain, and makes use of the friction of the reverse chain to continuously rotate the steel pipe. The movement of the reverse chain also makes the steel pipe always rely on the jaw plate of the front transmission chain to achieve smooth rotation and uniform cooling.
2, single chain cold bed
The single strand cold bed adopts a climbing structure. The cooling bed includes a forward conveyor chain and a fixed guide rail with a drive system. The steel tube is placed between the two handles of the forward transport chain, and the fixed rail bears the weight of the steel tube body. The single strand cooling bed uses the friction force of the forward chain claw and the fixed guide rail to rotate the steel tube, and at the same time, depending on the weight and the lifting angle of the steel, the steel pipe is always close to the forward chain claw to achieve the smooth rotation of the steel.
3, a new chain of cold bed
Combined with the characteristics of single cooling bed and double share cooling bed, the cold bed is divided into uphill and downhill. The uphill part is a double chain structure consisting of the forward transport chain and the reverse transport chain. The positive and negative interactions make the steel tube move forward and climb. The downhill section is a single chain structure parallel to the progressive transportation chain and the steel pipe, which realizes self rotation by self weight and makes the landslide movement.
4, step type cold bed
The step type cooling bed is made up of two groups of shelves. One group is fixed on the fixed beam, which is called static frame and the other is assembled on the movable beam, which is called mobile frame. When the mechanism moves, the mobile rack is lifted, the steel pipe is lifted, and the steel pipe is rolled into a toothed shape when it is raised. After the mobile gear reaches the highest position, the stepping mechanism moves the mobile frame along the direction of the cooling bed output to a step. The lifting mechanism continues to move, driving the moving bracket down, inserting the steel pipe into the stator slot, rolling the steel tube along the tooth tooth again, and moving the frame back to the initial position to complete the working cycle.
5, spiral cold bed
The screw is composed of main drive, screw and fixed cooling platform. The screw includes screw and screw screw. The working surface of the fixed cooling platform is higher than that of the spiral core and the helix. The weight of the steel pipe body is borne by the fixed cooling platform. The main drive drives the screw to rotate synchronously, and the screw on the screw drives the steel tube to roll forward and cool on the fixed cooling table.
Single strand cold bed is not suitable for continuous operation, double cold bed is better, new chain type cold bed has good effect and low cost. The step type cold bed is usually used for large or high configuration production line, and spiral cold bed is usually used to cool small diameter seamless pipe.
1, double strand cold bed
The dual cooling bed includes a forward transport chain and a reverse transport chain, each transmission chain with a transmission system. The steel pipe is placed between the two lines of the forward transport chain, and the reverse chain carries the weight of the pipe body. The double bed cooling bed pushes the steel pipe forward with the thrust of the forward transport chain, and makes use of the friction of the reverse chain to continuously rotate the steel pipe. The movement of the reverse chain also makes the steel pipe always rely on the jaw plate of the front transmission chain to achieve smooth rotation and uniform cooling.
2, single chain cold bed
The single strand cold bed adopts a climbing structure. The cooling bed includes a forward conveyor chain and a fixed guide rail with a drive system. The steel tube is placed between the two handles of the forward transport chain, and the fixed rail bears the weight of the steel tube body. The single strand cooling bed uses the friction force of the forward chain claw and the fixed guide rail to rotate the steel tube, and at the same time, depending on the weight and the lifting angle of the steel, the steel pipe is always close to the forward chain claw to achieve the smooth rotation of the steel.
3, a new chain of cold bed
Combined with the characteristics of single cooling bed and double share cooling bed, the cold bed is divided into uphill and downhill. The uphill part is a double chain structure consisting of the forward transport chain and the reverse transport chain. The positive and negative interactions make the steel tube move forward and climb. The downhill section is a single chain structure parallel to the progressive transportation chain and the steel pipe, which realizes self rotation by self weight and makes the landslide movement.
4, step type cold bed
The step type cooling bed is made up of two groups of shelves. One group is fixed on the fixed beam, which is called static frame and the other is assembled on the movable beam, which is called mobile frame. When the mechanism moves, the mobile rack is lifted, the steel pipe is lifted, and the steel pipe is rolled into a toothed shape when it is raised. After the mobile gear reaches the highest position, the stepping mechanism moves the mobile frame along the direction of the cooling bed output to a step. The lifting mechanism continues to move, driving the moving bracket down, inserting the steel pipe into the stator slot, rolling the steel tube along the tooth tooth again, and moving the frame back to the initial position to complete the working cycle.
5, spiral cold bed
The screw is composed of main drive, screw and fixed cooling platform. The screw includes screw and screw screw. The working surface of the fixed cooling platform is higher than that of the spiral core and the helix. The weight of the steel pipe body is borne by the fixed cooling platform. The main drive drives the screw to rotate synchronously, and the screw on the screw drives the steel tube to roll forward and cool on the fixed cooling table.
Single strand cold bed is not suitable for continuous operation, double cold bed is better, new chain type cold bed has good effect and low cost. The step type cold bed is usually used for large or high configuration production line, and spiral cold bed is usually used to cool small diameter seamless pipe.
2018年5月6日星期日
Seamless steel pipe production equipment requirements
There are some common production equipment for steel pipes. And of course, different types of steel pips would need the different production equipment for the special process too. Today, Tianjin Xinyue Steel Group would have an introduction for production equipment for seamless steel pipe.
Piercing mill: Taking conical-roler as quick-rolling and uniform tubularible thickness, it is widely used in seamless steel pipe's production. It is easy to adjust for feeding angle and toe angle.
Slight-stretch reducing mill: This kind of machine has three rollers for respective-power-transmission. Its flexible adjustment would make it high-precised outer diameter and superior when used for surface finishing.
Rotating heat furnace: It is available for single or dual-feeding type. Its automated furnace-temp-erature would save labor's energy.
http://www.xysteelpipe.com/info/Seamless-steel-pipe-production-equipment-requirements-1051-1.htm
Piercing mill: Taking conical-roler as quick-rolling and uniform tubularible thickness, it is widely used in seamless steel pipe's production. It is easy to adjust for feeding angle and toe angle.
Slight-stretch reducing mill: This kind of machine has three rollers for respective-power-transmission. Its flexible adjustment would make it high-precised outer diameter and superior when used for surface finishing.
Rotating heat furnace: It is available for single or dual-feeding type. Its automated furnace-temp-erature would save labor's energy.
http://www.xysteelpipe.com/info/Seamless-steel-pipe-production-equipment-requirements-1051-1.htm
Surface treatment of stainless steel tubes
Generally, in terms of the surface treatment for stainless steel pipes, manufacturers have three methods, blenching treatment, polishing treatment and coloring treatment. However, it’s unavoidable to have some problems during the surface treatment, mainly are the following problems.
1. Defects of welding crevice. When the defects are serious, usually can apply the mechanical polishing process to deal it, however, this method may cause grinding marks and result in the uneven surface and influence the appearance of pipes.
2. Uneven surface. If only give pickling passivation to welding crevice, it will also cause the uneven surface and affect the appearance of pipes.
3. Uneven polishing. For the lager object, carrying pickling passivation after manual polishing is also difficult to reach the even surface and the processing is time and cost consuming.
4. Limited capacity of acid washing. The pickling passivation is not a panacea for all kind of surface treatment. It’s also hard to remove the black scale cinder on the stainless steel pipe which is produced by plasma cutting and flame cutting.
5. Equipment factors. Bending and rolling the profile also may cause scratches and the main reason for rust after treatment.
6. Human factor. Human factors may lead to serious scratches during lifting, transporting and processing and it’s unavoidable to have bumping, dragging and hammering. All these factors will make the surface treatment more difficult and also the main reason for rust after treatment.
7. Other factors. The raw material of stainless steel pipe may have scratches during purchasing, storing and transporting which is also the reason to cause rust.
http://www.xysteelpipe.com/info/Surface-treatment-of-stainless-steel-tubes-1052-1.htm
1. Defects of welding crevice. When the defects are serious, usually can apply the mechanical polishing process to deal it, however, this method may cause grinding marks and result in the uneven surface and influence the appearance of pipes.
2. Uneven surface. If only give pickling passivation to welding crevice, it will also cause the uneven surface and affect the appearance of pipes.
3. Uneven polishing. For the lager object, carrying pickling passivation after manual polishing is also difficult to reach the even surface and the processing is time and cost consuming.
4. Limited capacity of acid washing. The pickling passivation is not a panacea for all kind of surface treatment. It’s also hard to remove the black scale cinder on the stainless steel pipe which is produced by plasma cutting and flame cutting.
5. Equipment factors. Bending and rolling the profile also may cause scratches and the main reason for rust after treatment.
6. Human factor. Human factors may lead to serious scratches during lifting, transporting and processing and it’s unavoidable to have bumping, dragging and hammering. All these factors will make the surface treatment more difficult and also the main reason for rust after treatment.
7. Other factors. The raw material of stainless steel pipe may have scratches during purchasing, storing and transporting which is also the reason to cause rust.
http://www.xysteelpipe.com/info/Surface-treatment-of-stainless-steel-tubes-1052-1.htm
The Difference between Hot Rolled and Cold Rolled Square Steel Pipe
Hot rolled carbon square tube and cold formed steel hollow section square pipe is a process, they have a great impact on the microstructure and properties of steel, rolled steel, hot-rolled mainly based, only for the production of cold-rolled trumpet steel and sheet.
Hot-rolled
Pros: You can destroy ingot casting organizations, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent in the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure.
Disadvantages: After hot rolling, the hot rolled square hollow section steel pipe inside the non-metallic inclusions (mainly sulphide and oxide, and silicates) is pressed into the sheet, delamination (interlayer) phenomenon. Layered in the thickness direction of the steel tension performance deteriorated significantly, and there may be an interlayer tear weld shrinkage. Weld local strain-induced contraction of the yield point strain often reach several times larger than the load caused by the strain.
Cold-rolled
Advantages: forming speed, high yield, and does not damage the coating, can be made into a variety of cross-sectional form, needs to adapt to the conditions of use; cold-rolled steel to produce large plastic deformation, thereby increasing the yield of steel point.
Disadvantages: 1 Although the molding process without thermal plastic compression, but there are still residual stress within the cross-section of the overall and local buckling characteristics of steel will inevitably have an impact;
2 Cold formed square steel pipe style is generally open section, so that the free section. low torsional stiffness. When flexural prone to twisting, bending and torsion when the pressure is prone to buckling, torsional performance is poor.
http://www.tjxysteel.com/news/Hot-Rolled-and-Cold-Rolled-Square-Steel-Pipe-261.html
Hot-rolled
Pros: You can destroy ingot casting organizations, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent in the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure.
Disadvantages: After hot rolling, the hot rolled square hollow section steel pipe inside the non-metallic inclusions (mainly sulphide and oxide, and silicates) is pressed into the sheet, delamination (interlayer) phenomenon. Layered in the thickness direction of the steel tension performance deteriorated significantly, and there may be an interlayer tear weld shrinkage. Weld local strain-induced contraction of the yield point strain often reach several times larger than the load caused by the strain.
Cold-rolled
Advantages: forming speed, high yield, and does not damage the coating, can be made into a variety of cross-sectional form, needs to adapt to the conditions of use; cold-rolled steel to produce large plastic deformation, thereby increasing the yield of steel point.
Disadvantages: 1 Although the molding process without thermal plastic compression, but there are still residual stress within the cross-section of the overall and local buckling characteristics of steel will inevitably have an impact;
2 Cold formed square steel pipe style is generally open section, so that the free section. low torsional stiffness. When flexural prone to twisting, bending and torsion when the pressure is prone to buckling, torsional performance is poor.
http://www.tjxysteel.com/news/Hot-Rolled-and-Cold-Rolled-Square-Steel-Pipe-261.html
2018年5月4日星期五
Storage requirements for steel pipes
Pipe may not be directly stacked on the floor, steel or concrete surface, the first layer of steel pipe from the ground at a distance not less than 0.20m. To avoid pipe damp, dust and pollution, steel pipe (or tube bundle) shall be placed in a dusty, damp places, tying both ends of the pipe must be protected with plastic or paper bags, etc., to prevent dust from entering.
Rack or stack level should be neatly arranged, and there is a clear marker number. Pipe should heat number (Lot), variety of different sizes and materials are placed in the designated rack or stack position. The same rack or stack position is not allowed to store the same size as (or similar), the same type of material and outline different heats of steel.
To prevent bending or steel pipe table injury, steel pipe (or tube bundles) should be placed at appropriate intervals and in the same horizontal plane on the sleepers, end of the tube to ensure alignment. For annealed brass, aluminum and similar hose should be placed between layers of isolation sleepers, each for at least two sleepers should be placed in a vertical pipe, and up and down on the positive, to ensure straight alignment. If the pipe
In case of the absence of feeder layer code (including code square stamp) stacked, should be properly placed wedge or use other methods to prevent rolling of steel pipe.
After cold-rolled, cold-drawn or bright annealed steel pipe does not allow open storage. If that stock conditions, open storage should be required to take appropriate precautions to avoid rain, snow, fog and other corrosive media and a lot of dust pollution pipe.
Rack or stack level should be neatly arranged, and there is a clear marker number. Pipe should heat number (Lot), variety of different sizes and materials are placed in the designated rack or stack position. The same rack or stack position is not allowed to store the same size as (or similar), the same type of material and outline different heats of steel.
To prevent bending or steel pipe table injury, steel pipe (or tube bundles) should be placed at appropriate intervals and in the same horizontal plane on the sleepers, end of the tube to ensure alignment. For annealed brass, aluminum and similar hose should be placed between layers of isolation sleepers, each for at least two sleepers should be placed in a vertical pipe, and up and down on the positive, to ensure straight alignment. If the pipe
In case of the absence of feeder layer code (including code square stamp) stacked, should be properly placed wedge or use other methods to prevent rolling of steel pipe.
After cold-rolled, cold-drawn or bright annealed steel pipe does not allow open storage. If that stock conditions, open storage should be required to take appropriate precautions to avoid rain, snow, fog and other corrosive media and a lot of dust pollution pipe.
How is the market growth rate of steel pipe
Due to multifarious factors, there is analysis for the steel pipe’s market growth rate. No matter you are seamless steel pipe, ERW steel pipe or galvanized steel pipe, we should have a basic analysis for recent year’s volume of selling.
First of all, Tianjin Xinyue Steel Group would make a basic database for supply according to supply ability of 600 Metric Ton/Metric Tons per Day.
What’s more, we would like to make a selling plan combining the market demands for steel pipe.
Of course, the conjunction of workmanship and artistry in making steel pipes decides the value of them. So we should make considerable price according to the quality of steel pipes.
When we figure out the basic information, then we can make a guess for the future market growth of steel pipe now.
http://www.xysteelpipe.com/info/How-is-the-market-growth-rate-of-steel-pipe-1047-1.htm
First of all, Tianjin Xinyue Steel Group would make a basic database for supply according to supply ability of 600 Metric Ton/Metric Tons per Day.
What’s more, we would like to make a selling plan combining the market demands for steel pipe.
Of course, the conjunction of workmanship and artistry in making steel pipes decides the value of them. So we should make considerable price according to the quality of steel pipes.
When we figure out the basic information, then we can make a guess for the future market growth of steel pipe now.
http://www.xysteelpipe.com/info/How-is-the-market-growth-rate-of-steel-pipe-1047-1.htm
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