Simmered steel elbow weld locations The inner arc is at 45 degrees. The welded elbow is made of bent pipe and can be welded, so it is called a welded elbow. It does not mean that it has a weld itself. It is quite the opposite. Since the welded elbow is made of straight pipes, it is considered that For structural stress problems, seamless pipes are generally used. instead of welded pipe. The so-called seamless elbow is a casting and cannot be welded. What kind of pickling is commonly used for steel elbows? The commonly used pickling of welded elbows is the same in the quality process. The acids used for pickling include sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, chromic acid, hydrofluoric acid, and mixed acids. The most commonly used are sulfuric acid and hydrochloric acid. The pickling processes mainly include immersion pickling, spray pickling, and acid paste rust removal. Generally, the dipping and pickling method is used, and the spraying method can be used in mass production.

Defects that are prone to occur in the submerged arc welding zone include pores, hot cracks, and undercuts. 1. Bubbles. Bubbles mostly occur in the center of the weld bead. The main reason is that hydrogen is still hidden in the welded metal in the form of bubbles. Therefore, the measure to eliminate this defect is to first remove rust, oil, water, and moisture from the welding wire and weld. substance, followed by drying the flux well to remove moisture. In addition, increasing the current, reducing the welding speed, and slowing down the solidification rate of the molten metal is also very effective. 2. Sulfur cracking (cracks caused by sulfur). Cracks caused by sulfides in the sulfur segregation zone enter the weld metal when welding plates with strong sulfur segregation zones (especially soft boiling steel). The reason is that the sulfur segregation zone contains low melting point iron sulfide and the presence of hydrogen in the steel. Therefore, to prevent this situation, it is effective to use semi-killed steel or killed steel with less sulfur segregation zone. Secondly, it is also necessary to clean and dry the weld surface and flux. 3. Thermal cracks. In submerged arc welding, hot cracks can occur in the weld bead, especially in the arc starting and arc extinguishing craters. To eliminate this kind of crack, backing plates are usually installed at the arc starting and arc extinguishing points, and at the end of the plate coil butt welding, the spiral welded pipe can be reversed and welded into the stick welding. Hot cracks are prone to occur when the stress in the weld is very high, or when the pressure in the weld metal is very high. 4. Inclusion of welding slag. The inclusion of welding slag means that part of the welding slag remains in the weld metal. 5. Poor welding penetration. The metal overlap of the inner and outer welds is not enough, and sometimes the welding is not penetrated. This condition is called insufficient weld penetration. 6. Undercut. Undercut is a V-shaped groove appearing on the edge of the weld along the center line of the weld. Undercut occurs when welding speed, current, voltage, and other conditions are inappropriate. Among them, too high welding speed is more likely to cause undercut defects than inappropriate current.

1. The two main methods commonly used for anti-corrosion of steel pipelines are outer coating and cathodic protection. 2. Although most of the surface of the steel pipeline is covered by the coating, a slight leak will cause incredible corrosion rates, or even holes or cracks. Therefore, in the anti-corrosion of steel pipelines, the coating system and cathodic protection are generally used in combination to achieve 99.99% coverage to avoid unimaginable consequences in the future. 3. The cathodic protection selected for anti-corrosion of steel pipelines is divided into dedicated cathodic protection and impressed current cathodic protection. 4. The purpose of the anti-corrosion coating for 3PE anti-corrosion steel pipes is to form a continuous covering layer of insulating material to directly insulate the metal from the electrolyte in direct contact, so that no correct electrolytic reaction can occur. 5. Disconnected points during the coating laying process are called leakage points. The main reason for occurrence is during coating, transportation or installation. It may also occur due to coating aging, soil stress or movement of steel pipes in the soil. , failure to discover damage caused by a third party in a timely manner.

1. Mechanical cutting adopts external installation and internal installation. It uses the turning tool processing principle to cut and bevel the pipe mouth. The single machine has a large span, can process large thicknesses, has less waste, is pollution-free, and does not produce high temperatures during the processing. It does not affect the pipe material and is conducive to welding. Water cutting uses a high-pressure pump and emery to process pipes. Its cuts are clean and the processing span is large. However, its efficiency is low and the processing thickness is seriously limited. 2. Oxyacetylene flame cutting, by adjusting the oxygen valve and acetylene valve, the mixing ratio of oxygen and acetylene can be changed to obtain three different flames: neutral flame, oxidizing flame, and carbonizing flame. 3. Ion cutting, plasma cutting with different working gases can cut various metals that are difficult to cut with oxygen cutting, especially for non-ferrous metals (stainless steel, aluminum, copper, titanium, nickel), the cutting effect is better; its main advantage is the cutting thickness When cutting small metals, plasma cutting speed is fast, especially when cutting ordinary carbon steel thin plates, the speed can be up to 5 to 6 times that of oxygen cutting. The cutting surface is smooth, the thermal deformation is small, and there is less heat-affected zone.

Pushing elbows: The process of pushing steel elbows using machinery + mold inner tube + medium frequency heating method. However, it may be that the thickness of the inner and outer walls is difficult to control, and it is rarely used in practical applications. Socket weld elbow: Most are forged. In engineering, sockets are used when DN is less than or equal to 40 and there are no special requirements. A push elbow is a push-formed elbow. Nowadays, the most important elbow-forming production process is the push-formed elbow. First of all, the push-formed elbow is also a push-formed elbow production. The production speed is fast, and the push elbow can be produced in batches. The quality of the push elbow is good. The push elbow-forming process is now the most important elbow-forming production process. Socket elbow: It is a high-pressure elbow pipe connection fitting that is mainly formed by die-forging blanks of round steel or steel ingots, and then machined by a lathe. It is a type of forged socket series pipe fittings. Commonly used standards Commonly used standards for socket elbows include GB/T14383-93, GB/T14383-2008, American standard ASME B16.11, petrochemical standard SH3410, Ministry of Chemical Industry standard HG/T21634, etc. Specification form According to the form, it is divided into 45° socket elbow and 90° socket elbow. According to common standards, the specifications of socket elbows are DN6, DN8, DN10, DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, and DN100. The commonly used ordering specifications are DN15----DN50. If there is anything beyond the scope of this specification, we can communicate with the customer for drawing design and processing. Pressure Level Distinguished according to pressure level: 3000LB, 6000LB, 9000LB or SCH80, SCH160, XXS Commonly used manufacturing materials Commonly used raw materials for socket pipe fittings are generally divided into carbon steel, stainless steel, alloy steel, etc. Commonly used grades of carbon steel include Q235, 20#, A105, etc.; Commonly used grades of stainless steel include 304, 304L, 316, 316L, 321, 00Cr17Ni14Mo2, etc.; Commonly used grades of alloy materials include 15CrMo, 1Cr5Mo, 16Mn, 12Cr1MoV, F11, F22, 10CrMo910, etc. Other materials: copper alloy, nickel alloy, etc.

Welding and cutting of spiral steel pipe structures are inevitable in spiral steel pipe applications. Due to the characteristics of the spiral steel pipe itself, the welding and cutting of the spiral steel pipe has its particularities compared with ordinary carbon steel. It is more likely to produce various defects in its welded joints and heat-affected zone (HAZ). The welding performance of the spiral steel pipe is mainly reflected in the following aspects, high-temperature cracks. The high-temperature cracks mentioned here refer to cracks related to welding. High-temperature cracks can be roughly divided into solidification cracks, microcracks, HAZ (heat-affected zone) cracks, and reheating cracks. Low-temperature cracks Low-temperature cracks sometimes occur in spiral steel pipes. Because the main causes are hydrogen diffusion, the degree of constraint of the welded joint, and the hardened structure therein, the solution is mainly to reduce the diffusion of hydrogen during the welding process, appropriately perform preheating and post-weld heat treatment, and reduce the degree of constraint. The toughness of welded joints in spiral steel pipes is usually designed to contain 5% to 10% ferrite to reduce the susceptibility to high-temperature cracks. However, the presence of these ferrites leads to a decrease in low-temperature toughness. When spiral steel pipes are welded, the amount of austenite in the welded joint area is reduced, which affects the toughness. In addition, as the ferrite increases, its toughness value has a significant downward trend. It has been proven that the toughness of welded joints of high-purity ferritic stainless steel decreases significantly because of the mixing of carbon, nitrogen, and oxygen. The increase in oxygen content in the welded joints of some steels generates oxide-type inclusions. These inclusions become the source of cracks or the path for crack propagation, causing the toughness to decrease. Some steels are mixed with air in the protective gas, and the nitrogen content increases, producing lath-like Cr2N on the cleavage plane {100} of the matrix. The matrix becomes hard and the toughness decreases. σ phase embrittlement: Austenitic stainless steel, ferritic stainless steel, and duplex steel are prone to σ phase embrittlement. Because a few percent of the α phase is precipitated in the structure, the toughness is significantly reduced. The "phase" generally precipitates in the range of 600 to 900°C, especially around 75°C. As a preventive measure to prevent the occurrence of the " phase, the ferrite content in austenitic stainless steel should be reduced as much as possible. Embrittlement at 475°C, and when kept at 475°C (370-540°C) for a long time, the Fe-Cr alloy decomposes into an α solid solution with a low chromium concentration and an α’ solid solution with a high chromium concentration. When the chromium concentration in the α’ solid solution is greater than 75%, the deformation changes from slip deformation to twin deformation, resulting in 475°C embrittlement.

1. Mainly use tools such as wire brushes to polish the steel surface. Cleaning and preheating the spiral welded pipe can remove loose or lifted scales, rust, welding slag, etc. The rust removal of hand tools can reach the Sa2 level, and the rust removal of power tools can reach the Sa3 level. If the iron oxide scale is firmly attached to the surface of the steel, the rust removal effect of the tool will not be ideal and the anchor pattern depth required for anti-corrosion construction will not be achieved. 2. Pickling uses solvents and emulsions to clean the surface of welded steel pipes (welded pipes) for low-pressure fluid transportation to remove oil, grease, dust, lubricants, and similar organic matter, but it cannot remove rust, oxide scale, and flux on the steel surface. etc., so it is only used as an auxiliary means in anti-corrosion production. 3. Generally, chemical and electrolytic methods are used for pickling treatment. Only chemical pickling is used for pipeline anti-corrosion, which can remove scale, rust, and old coatings. Sometimes it can be used as a reprocessing after sandblasting and rust removal. Although chemical cleaning can achieve the highest cleanliness and roughness on the surface, its anchor lines are shallow and it is easy to cause pollution to the spiral welded pipe stacking environment.

First: It may be due to the stress of spiral submerged arc welded steel pipes. That is, the residual stress and welding stress after the steel pipe is formed. Second: due to the presence of hydrogen. For example, the flux is not dried enough, the preheating temperature is insufficient preheating before welding is not carried out, and the interlayer temperature of multi-layer welding is not enough. Third: Metallurgical factors of spiral welded steel pipes. During the welding process, low melting point impurities enter, such as copper and copper alloys. The main source of copper is copper plated on the surface of the welding wire to prevent corrosion of the welding wire. These copper shavings enter the flux from the inner hole of the contact tip and contact the welding pool during the welding process, causing transverse cracks. Fourth: The welding process of spiral seam submerged arc welded steel pipe is unreasonable. For example, the weld forming coefficient is too small, the preheating temperature is not enough or no preheating before welding, the welding line energy is too large, the heat treatment after welding is improper, the holding time is too short, etc. If there is welding slag during spiral seam submerged arc welding of steel pipes, use argon arc welding, or wait for the stainless steel welded pipe to cool down and then hit it with a hammer and it will fall off. These two methods are relatively simple, but they may not be clean. Welding slag is relatively easy to clean, but splashed slag is difficult to clean. If you can use electric grinding to clean welding slag, use electric grinding. Otherwise, it will be difficult to clean off welding slag. As for some defects that occur when cutting spiral welded steel pipes, we can also remove them, but if we want to remove these defects, we must find a reasonable method. Only the correct method can make up for the defects of welded pipes. Corresponding solutions can be found for these defects, but if the method is not found correctly, it will make use more troublesome. Another way to clean welding slag from welded pipes is to use a file. Using a file can also clean the welding slag very cleanly. Another simpler and more labor-saving method is to take a saw blade or half heel, reach into the pipe, hold the pipe in your left hand, and the saw blade in your right hand, and pull it clockwise or counterclockwise. This allows the welding slag in the welded pipe to be cleaned very cleanly without wasting too much time, making it simple and convenient.

1. The uses of large-diameter stainless steel can be divided into oil well pipes (casing, oil pipes, drill pipes, etc.), pipeline pipes, boiler pipes, mechanical structural pipes, hydraulic support pipes, gas cylinder pipes, geological pipes, and chemical pipes (high-pressure fertilizers). pipes, petroleum cracking pipes) and ship pipes, etc. 2. The thicker the wall thickness of the solution, the more cost-effective and sensible it is; the thinner the wall thickness, its processing cost will appreciate significantly; 3. The product process determines its limitations, from the low precision of general seamless steel pipes: uneven wall thickness, low brightness tube appearance, high cost of fixed length, and the appearance of pitting corrosion, black spots are difficult to remove Walk; 4. Detection and plastic must be processed offline. So it's the higher pressure, high strength, mechanical structural wood that reflects its superiority. 5. The corrosion resistance of large-diameter stainless steel welded pipes depends on the alloy components contained in the steel. Chromium is the basic component of corrosion-resistant stainless steel. About 12% of the chromium is in steel. Chromium interacts with oxygen in the corrosive medium to form a thin oxide film (passivation film) matrix on the surface of the steel, which can prevent further corrosion of the steel. Remove chromium, stainless steel seamless steel pipe common alloy components you will find nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the specifications of different stainless steel structures and properties. Reducer tubes, and steel pipe fittings, are widely utilized in various industries to provide flexibility in connecting sections of pipe in several installations. A reducer can connect two pipes of different diameters with one fitting. Pipe reducers are readily supplied in a range of dependent end-use commodity fittings produced in both imperial and metric sizes. Advantages of large diameter stainless steel pipes: 1. Welded steel pipes are produced continuously online. The thicker the wall thickness, the greater the investment in the unit and welding equipment, and the less economical and practical it is. The thinner the wall thickness, the lower its input-output ratio will be. 2. The technology of this product ensures that generally welded steel pipes have high precision, uniform wall thickness, and high internal and external brightness (the surface brightness of the steel pipe is determined by the surface grade of the steel plate), and can be arbitrarily cut to length. Therefore, it reflects its economy and aesthetics in high-precision, medium, and low-pressure fluid applications. 3. The production process of welded steel pipes is simple, with high production efficiency, low cost, and rapid development. The strength of spiral welded pipes is generally higher than that of straight seam welded pipes. Welded pipes with larger diameters can be produced from narrower billets, and welded pipes with different diameters can also be produced from billets of the same width. However, compared with straight seam pipes of the same length, the weld length is increased by 30 to 100%, and the production speed is lower. Therefore, smaller diameter welded pipes mostly use straight seam welding, while large diameter welded pipes mostly use spiral welding.

While the ASTM and ASME standards for steel and other metals are very similar, if not identical, there may be slight differences between A36 and SA36 grades depending on the criteria used by each organisation. In fact, ASTM A36 and ASME SA36 are the only two standards that exist, ASTM SA36 is not. For use in bridges and buildings that are riveted, bolted or welded, and for general structural purposes, ASME A36 specifies carbon steel shapes, rounds and bars, while ASME contains design standards for pressure applications. In most cases, ASME standards are based on ASTM standards, although their numbers are prefixed with the letter 'SA' rather than just the letter 'A' as in ASTM.

Monel Sheet and Plate Specification : ASTM B127 / ASME SB127 Dimension Standard : JIS, AISI, ASTM, GB, DIN, EN, etc. Width : 1000mm, 1219mm, 1500mm, 1800mm, 2000mm, 2500mm, 3000mm, 3500mm, etc. Length : 2000mm, 2440mm, 3000mm, 5800mm, 6000mm, etc. Thickness : 0.3mm to 120mm

Monel 400/K500 sheets and plates are valued for their dimensional accuracy and ease of installation. In fact, it is a sheet and plate that can be easily hardened by cold working. The product also has good ductility and even good thermal conductivity. So the machinability of these sheets and plates is somewhat difficult as it works on hardness during the time of machining. The product is very strong and has about three times the yield strength and about twice the tensile strength. And this is even compared to other elements. The property of resistance is also there, it is resistant to rust.

Stainless Steel Plates and Sheets Specification : ASTM A240 / ASME SA240 Dimension Standard : JIS, AISI, ASTM, GB, DIN, EN, etc. Width : 1000mm, 1219mm, 1500mm, 1800mm, 2000mm, 2500mm, 3000mm, 3500mm, etc. Length : 2000mm, 2440mm, 3000mm, 5800mm, 6000mm, etc. Thickness : 0.3mm to 120mm

Stainless steel 253 MA is actually an austenitic material which has very good strength and excellent resistance to oxidation up to a temperature range of 2000 deg F and it also resists high heats. In this material carbon, nitrogen and rare earth and alkali metal oxide dispersions mix together to provide very good creep strength. SS 253 MA steel is the material that is designed to make it useful at the temperature that is greater than 550 deg C. Therefore the 253MA Sheets & Plates are said to be ideal for use in the temperature ranges of 850-1100 deg C.

Construction and infrastructure projects require careful planning and execution to ensure their success. An essential aspect of these projects is the selection of the right plumbing equipment, such as pipes and fittings. One of the most commonly used fittings in these projects is the 45 degree elbow. This fitting has numerous advantages that make it an ideal choice for construction and infrastructure projects. This blog post explores the benefits of using 45 degree elbows in construction and infrastructure projects.

The anti-corrosion layer of steel pipelines should have the following properties: (1) Effective electrical insulation. (2) It has good moisture-proof and waterproof properties. (3) It has strong mechanical strength. (4) The anti-corrosion layer has good adhesion to the steel surface. (5) The material and construction technology of the anti-corrosion layer should not hurt the performance of the masterbatch. (6) It has good resistance to cathodic stripping. (7) It has good chemical resistance and aging resistance. (8) Damage to the anti-corrosion layer is easy to repair. (9) The impact of the anti-corrosion layer on the environment should meet the corresponding requirements.

High-frequency welding management properties: normal temperature mechanical properties, high-temperature mechanical properties, low-temperature properties, and corrosion resistance. The physical and chemical properties of high-frequency welded steel pipes mainly depend on the chemical composition of the steel, the organizational structure, and the purity of the steel, as well as the heat treatment method of the high-frequency welded steel pipes. High-frequency welded steel pipe process performance: flattening, flaring, curling, bending, welding, etc. High frequency welded steel pipe metallographic structure: low magnification structure (macro), high magnification structure (micro) M, B, P, F, A, S Special requirements for high-frequency welded steel pipes: contract attachments and technical agreements. High-frequency welded steel pipe inspection method: First, chemical composition analysis: chemical analysis method, instrumental analysis method (infrared C-S instrument, direct reading spectrometer, zcP, etc.). 1. Infrared C-S meter: analyze ferroalloys, steelmaking raw materials, and C and S elements in steel. 2. Direct reading spectrometer: C, Si, Mn, P, S, Cr, Mo, Ni, Cn, A1, W, V, Ti, B, Nb, As, Sn, Sb, Pb, Bi 3. N-0 meter: gas content analysis N, O ​ Second, geometric dimensions and appearance inspection of high-frequency welded steel pipes: 1. High-frequency welded steel pipe wall thickness inspection: micrometer, thickness gauge, no less than 8 points at both ends and recorded. 2. Inspection of the outer diameter and ovality of high-frequency welded steel pipes: calipers, vernier calipers, and ring gauges to detect large and small points. 3. High-frequency welded steel pipe length inspection: steel tape measure, manual, automatic length measurement. 4. High-frequency welded steel pipe bending inspection: ruler, level (1m), feeler gauge, thin wire to measure bending per meter, and full-length bending. 5. High-frequency welded steel pipe end bevel angle and blunt edge inspection: square ruler, clamping plate. Third, high-frequency welded steel pipe surface inspection: 100% 1. Manual visual inspection: lighting conditions, standards, experience, markings, high-frequency welded steel pipe rotation. 2. Non-destructive inspection: lighting conditions, standards, experience, markings, high-frequency welded steel pipe rotation. 3. Wave flaw detection UT: It is sensitive to surface and internal crack defects of uniform materials of various materials. ​

For Immediate Sale We have a stock of pipe fittings on sale that can be ready to ship in 5-7 days. We offer special discounts on orders placed before the New Year and will send you a nice gift with your order. For a quote please contact us at sales@besta