steel tube

　　1. Eddy current detection 　　There are various methods of eddy current detection, such as conventional eddy current detection, far-field eddy current detection, multi-frequency eddy current detection, and pulse eddy current detection. Different types and shapes of defects on the surface of a rectangular tube can produce different types of signals. The invention has the advantages of high detection accuracy, high detection sensitivity and fast detection speed, can detect the surface and subsurface of the pipeline to be inspected, and is not affected by impurities such as oil on the surface of the rectangular pipeline to be inspected. The disadvantage is that it is easy to judge the defect-free structure as a defect, the false detection rate is high, and the detection resolution is not easy to adjust. 　　2. Ultrasonic inspection 　　When using ultrasonic waves to enter an object and encounter a defect, some sound waves will be reflected, and the transmitter and receiver can analyze ...

　　 Galvanized steel pipe , which has the advantages of two layers of corrosion resistance and long service life, and the price is relatively low, so its utilization rate is getting higher and higher, but some users do not Attention has caused some unnecessary trouble, so what problems should galvanized pipes pay attention to when welding? 　　The premise is to polish 　　It is necessary to polish off the galvanized layer at the welding place, otherwise air bubbles, trachoma and false welding will occur. It also makes the weld seams brittle and reduces rigidity. 　　Welding characteristics of galvanized steel 　　Galvanized steel is generally plated with a layer of zinc on the low-carbon steel, and the galvanized layer is generally 20um thick. Zinc has a melting point of 419 ° C and a boiling point of about 908 ° C. In welding, zinc melts into a liquid and floats on the surface of the molten pool or at the root of the weld. Zinc has a large solid solubility in iron. Zinc liquid will dee...

　　1. Carbon seamless steel pipe 　　Commonly used manufacturing materials are 10 #, 20 #, 16Mn steel. 　　Its standard planning is: hot rolled outer diameter φ32 ～ 630mm, cold drawn outer diameter φ6 ～ 200mm, single tube length 4 ～ 12m, and allowable operating temperature is -40 ～ 450 ℃. 　　It is widely used to transport various non-corrosive media such as steam, oxygen, compressed air, oil and oil and gas. 　　2. Low alloy steel seamless steel pipe 　　Refers to alloy steel pipes containing a certain proportion of alloying elements. 　　Generally divided into two types: 　　One is a low-alloy steel pipe containing manganese, known as a general low-alloy steel pipe, such as 16Mn, 15MnV, etc .; 　　The other is a low alloy steel pipe containing chromium, molybdenum and other elements, called chrome molybdenum steel pipe. 　　Commonly used are 12CrMo, 15CrMo, 12Cr2Mo, 1Cr5Mo, etc. The standard planning is an outer diameter of φ10 ～ φ273mm, the length of a single pipe is 4-12m, and the a...

　　According to the technical requirements of different manufacturers, steel length measuring system has a variety of methods. Mainly as follows: 　　1, grating length measurement 　　The basic principle is: set two fixed-length steel grating in the outer ends of each pipe, use rodless cylinder drive the grating approaching both ends of the steel , achieved by optical interference phenomenon to measure the length of the pipe. 　　Characterization: high accuracy. However, grating is expensive and difficult to maintain,and the impact of dust and vibration is sensitive to the venue. 　　2, the camera length measurement. 　　Camera length measurement is achieved by using image processing. The principle is equidistant installed in a steel roller conveyor section on a series of photoelectric switches, plus light and camera on the other section. When the pipe goes through this area, pipe length can be determined by the camera taking an image on a screen at a position based on a photoelectric s...

　　Oil well casing refers to the use of casing instead of drill pipe to apply torque and drilling pressure to the bit to achieve bit rotation and drilling. The whole drilling process no longer uses drill rods, drill collars, etc. The drill bit is fished with steel wire ropes, and the drill bit is lifted in the casing, that is, the drill bit is replaced without lifting. Reduced accidents such as tripping, blowout, stuck stuck, etc., improving drilling safety and reducing drilling costs. 　　1. Reduce the time of starting and drilling. It is about 5-10 times faster to replace the drill bit with a wire rope than with a traditional drill pipe. 　　2. Save on the purchase, transportation, inspection, maintenance and replacement costs related to drill pipes and drill collars; 　　3. Because there is always a casing in the wellbore, and there is no longer the pumping effect on the wellbore when the drill pipe is lowered, the well control situation is improved; 　　4. Eliminate the pumping effe...

　　Due to the characteristics of 3PE anticorrosive steel pipes , anticorrosive steel pipes have great advantages and practical needs in construction. 　　First, the construction of anticorrosive steel pipe is convenient, the steps are simple, convenient and quick, and processing plants and sites can be built. The anti-corrosion process is relatively simple and does not require major equipment and sites. Suitable for on-site construction, steel pipe can be made anti-corrosive construction at the same time. 　　The second is that the service life of 3PE anticorrosive steel pipes is longer, because there is a service life in the application of steel pipes. In addition to the corrosion protection of steel pipes, it also greatly improves the overall service life of the pipeline. Long, this is a noteworthy issue. We save money on replacement and maintenance. 　　Third, it is economically applicable and the construction cost is relatively low. When comparing the quality and service life of ste...

　　If the anti-corrosion layer of 3PE anti-corrosion steel pipe is too thin, it may be rejected on site. In this case, it can only be reprocessed. 　　In the 3PE steel pipe anticorrosive layer, if the powder adheres to the surface of the steel pipe, quality problems such as powder and adhesive, adhesive and polyethylene will damage the integrity of the 3PE steel anticorrosive layer. Such anticorrosive steel pipes should be rejected. When the thickness of the polyethylene layer exceeds the specification minimum, whether the thickness reduction point meets the requirements of the specification. Repair of repairable defects shall be allowed with patches or shrink sleeves. Otherwise, if possible, take measures to degrade the anticorrosive layer. Bubble defects, polyethylene cracks, and mechanical damage defects within the allowable range of the specification can be repaired with patches or shrink sleeves. Repairs are limited to repairing minor defects individually. 　　The warping of the e...

　　What are the ways to avoid wear on seamless steel tubes? 　　1. Seamless steel tube packaging should be able to prevent slackness and damage during normal loading, unloading, transportation and storage. 　　2. If the purchaser has special requirements for the packaging materials and packaging methods of the seamless steel pipe, it shall be specified in the contract; if not specified, the packaging materials and packaging methods are available to the supplier. 　　3. Packaging materials should conform to relevant rules. If no packaging information is required, it should be suitable for the intended use to prevent waste and environmental purification. 　　4. If the customer requires that the seamless steel pipe cannot be damaged on the surface, such as bumps, etc., you can consider the maintenance and installation between the seamless steel pipes. Maintenance and installation can use rubber, straw rope, fiber cloth, plastic, pipe caps, etc. 　　5. For thin-walled seamless steel pipes, ...

　　To ensure that the erw steel pipe in the winter welding perfect follow the following steps: 　　First, increase the welding current welding, slow down the welding speed, the appropriate increase in the cross-sectional area and length of the weld, if necessary, preheat. 　　Second, not outside the groove on the base metal to start arc, arc extinction to be filled when the pit. 　　Third, as far as possible not in low temperature conditions for bending, correction and assembly weldments. 　　Fourth, preheating before welding, welding process to strictly maintain the interlayer temperature should not be lower than the preheating temperature. 　　Fifth, the use of low hydrogen or ultra-low hydrogen welding materials. 　　Six, the entire weld should be finished as far as possible to avoid interruption.

　　Straight seam steel pipe wall thickness control is a difficult production. At present, the straight seam steel pipe manufacturers to improve the wall thickness in the production of precision uses the methods generally including: 　　1, Tube heating 　　Heating to the average to prevent rapid up and down temperature. Each take-off and landing temperature is to maintain a smooth slow, the maximum rise and fall temperature does not exceed 30 ℃. 　　2, Rolling mill mandrel 　　Average wall thickness of thick wall tube and solid billet make the probability of mandrel bending deformation significantly reduced, can effectively improve the wall thickness of the precision. 　　3, The accuracy of mandrel 　　The outer core of the machining accuracy control in ± 0.1mm, mandrel straightness bias does not exceed 5mm. Welding, the two core rods between the piercing a finishing pin positioning, welding in order to avoid the formation of the total straightness bias is too large. 　　4, The perfect ...

　　Ferritic stainless steel refers to the stainless steel with 10.5% ~ 30% Chromium content and without Nickel. The main grades including 405, 409, 410, 430, 434,439, 441, 445, 446, 447, of which the most widely used are 409, 410, 430 series. Ferritic stainless steels contain more chromium than Austenitic stainless steels, are less costly and can be used as an alternative material to the 304 or 200 series stainless steels sometimes. According to the chromium content, it can be divided into three groups: Cr10% ~ 15%, Cr16% ~ 20% and Cr21% ~ 30%. 　 　10% -14% Cr: 409、410L 　　409, 410 have the lowest chromium content and the cheapest in all of Ferritic stainless steels, suitable for environments where no corrosion or slight corrosion and local slight rust are allowed. Type 409 was originally designed specifically for automotive exhaust mufflers. 410L stainless steel low carbon content, welding parts of the bending performance, processing performance, good resistance to high temperature ...

　　 Straight seam steel pipe is widely used in various industries, such as petroleum, metallurgy, construction, coal mine, port, machinery and other industries. During the installation and use of straight seam steel pipes, there are strict technical requirements, which should be carried out according to actual conditions and operating specifications to ensure the safety and quality of straight seam steel pipes. In the normal use process, the following points need to be paid attention to: 　　1. Construction preparation before installation of straight seam steel pipe 　　The pipeline trench should be dug in accordance with the requirements of the drawings. After the bricking of the pipeline well is completed, the various types of straight seam steel pipes required have arrived, the quality is intact and the inspection is qualified. The required construction tools, including electric welding machines, cutting machines, Electric hammers, polishers, etc. are fully prepared, and installatio...

　　1. First of all, do a good job of meeting water quality standards, and strictly monitor and manage water quality. Carry out decontamination and injection, strengthen the cleaning of main water pipelines, achieve water quality standards in stations and bottoms, and reduce the introduction of corrosion sources into the annular space; 　　2. For water injection wells that have been newly put into production, adopt annulus protection fluid mainly based on dosing and sterilization, and form a system to do so on a regular basis; 　　3. In view of the accelerated effect of mechanical abrasion on the corrosion of petroleum casing, it is recommended to add a rubber ring to the tubing coupling or a centralizer in the serious area of the well to avoid the tubing from scratching the casing during the operation and water injection process and One side contacts the sleeve; 　　4. In view of the serious corrosion of the bacteria under the scale and the slow growth and killing of SRB under high temp...