Seamless Line Pipe

Seamless Line steel pipe refers to use seamless steel pipe production technology to produce. Pipeline steel tube is put out oil, steam, water, pipeline through the pipeline to oil and gas industry enterprise. Line pipe including seamless pipe and welded steel pipe, the pipe end with flat end, with threaded end and socket end; Its connection way as the end of welding, coupling connection, socket connection, etc.

High grade pipeline steel tube heat treatment process

With the development of the pipeline steel plate technology and the progress of welded pipe forming, welding technology, the application range of the pipe with welded pipe in gradually expanding, especially in the large diameter welded pipe class scope the advantage of more wet, and cost factors, welded pipe has been dominant in the field of line pipe, which limits the development of stainless steel seamless steel line pipe. About 2004 t 2004 seamless line pipe production, steel grade including X42-70, varieties have a seabed pipeline onshore pipeline steel pipe and carbon steel pipe.

Of high grade pipeline steel production is currently a micro alloying heat treatment process, the production cost of stainless steel seamless tube was obviously higher than that of welded pipe, and with the improvement of steel grade, such as the above X80 grade pipeline steel pipe for the limitation of carbon equivalent, seamless steel tube of conventional technology is difficult to meet user requirements; Now every 12 cr1mov alloy pipe factory in for the improvement of line pipe corrosion resistance, the use of stable performance and low temperature, high temperature environment to carry out the scientific research work.

Mild steel pipe weight calculation formula: [] - wall thickness (diameter) * wall thickness * = 0.02466 kg/m (weight of per meter)

At present in our country, the use of oil and gas transmission pipe of the main technical standards are API SPEC 5 l, GB/T 9711, DNV OS - F101, often involves the standard and ISO 3183, CSAZ662, roughly as follows:

(1) the API 5 l line pipe specification is beautiful because of the development of the petroleum institute a widely adopted standard. Specification only for steel pipe products, not including design, selection and installation of pipelines. Traditionally API 5 l is reasonable, the technical requirements for both the technical requirements of pipeline steel and factory's actual production possibilities, but the relative of pipeline and pipe technology development, the technical requirements of API 5 l appear to be loose, has rarely alone is suitable for the pipeline to the requirement of structural steel pipe.

(2) the DNV OS - F101 seabed pipeline (system) is a det norske veritas formulating specifications for subsea pipeline. Involves the content is very extensive, including pipeline design, material, manufacture, installation, testing, operation, maintenance and other aspects. Alone on the technical requirements for steel pipe are usually more strict than API 5 l.

(3) the ISO 3183 - l (- 2, 3) - (oil and gas industry conveying pipe delivery technical conditions in the first part: grade A steel pipe/second part; B steel pipe/third part; grade C steel) is established by the international organization for standardization about the standard of oil and gas transmission pipe delivery condition, according to the different service conditions of steel tube, divided into A, B, C three levels. The standard is not involved in pipeline design and installation, etc. Develop more comprehensive and detailed technical terms.

(4) GB/T 9711.1 (2) is China committee for standardization of tubing just standard committee equivalent adopting IS03183 "l (- 2) standard set by the oil delivery pipe used in industry technical conditions of delivery. API SPEC 5 l line pipe specification and the ISO 3183 (conveying pipe technical conditions of delivery) is the international has a great influence on the line pipe specification, in contrast, most of the world's oil companies are used to using the API SPEC 5 l specification as the basis of pipeline steel pipe procurement specification. Domestic according to the requirements of API SPEC 5 l standards and engineering design production pipeline steel is only 20 years of history. But the API SPEC 5 l is a common standard, geography, climate and other natural conditions vary widely from all over the world, the nature of the medium is different, therefore, many oil companies to call for the nature of the API are also different, therefore, many oil companies will API SPEC 5 l as a basic standard, on the basis of the standard, according to the requirements to the local actual situation or pipeline, formulate quality technical supplementary specification (technical conditions). West-east gas pipeline "technical conditions" of steel tube with API SPEC 5 l line pipe specification, as the foundation, combined with the specific situation of the west-east gas pipeline to develop.

The Use of Welded Steel Pipe or Application Range(2)

Transformer tube: for the manufacture of transformers and other caron steel pipe heat exchanger, using ordinary carbon steel, require flattening, flaring, bending, hydraulic tests. Pipe to length or double length delivery, bending the steel pipe has certain requirements.
Mild steel pipe: from general carbon structural steel and welded steel 16Mn, square tube, rectangular tube, cap -shaped tube, empty plastic steel doors and windows with steel, mainly for agricultural machinery components, steel window doors.
Welded thin-walled tube: mainly used to make furniture, toys, lamps, etc. In recent years, the production of thin-walled stainless steel tube with a very wide application, fine furniture, decoration, fences and so on.
Spiral welded pipe : It is the low-carbon carbon structural steel pipe or low alloy steel strip at a certain angle of the helix ( called molding angle ) rolled into a tube, then welded together to form the tube, it can be used narrower strip production of large diameter steel pipe. Spiral welded pipe is mainly used for oil and gas pipelines, and its diameter * thickness expressed. Spiral welded single-sided and double-sided welding, pipe should ensure that hydrostatic test, weld tensile strength and cold performance to meet the requirements.

The Use of Welded Steel Pipe or Application Range

General Pipe: Average welded steel pipe used to transport low pressure fluid. With Q195A, Q215A, Q235A steel. Easy welding may also be used in other soft steel. Pipe to carry water pressure, bending, flattening and other experiments, there are certain requirements for surface quality, delivery is usually a length of 4-10m, often required length (or double length) delivery. Pipe specifications expressed with nominal diameter (mm or inch) nominal diameter different from the actual, pipe wall thickness according to the provisions of ordinary steel and thicker steel are two forms of steel pipe end divided by threaded and non- threaded two kinds.
Galvanized steel pipe: To improve the corrosion resistance of steel, steel pipe for general (clarinet) galvanized. Galvanized coating steel pipe hot galvanized and zinc two kinds of electrical steel, hot dip galvanized thick galvanized, electro-galvanized and low cost.
Oxygen pipe: as steelmaking oxygen tube, usually with a small -diameter welded steel pipe, specification consists of 3 /8 inch -2 inch eight kinds. With 08,10,15,20 or Q195-Q235 steel is made. To corrosion, and some for aluminized.
Wire casing: also ordinary carbon steel welded pipes, used in a variety of structural concrete and distribution projects, common nominal diameter from 13-76mm. Wire condom wall is thinner, mostly used for coating or galvanized, cold bend test requirements .
Mild steel pipe: seamless form of specifications, with the diameter * thickness in millimeters of welded steel, with ordinary carbon steel, high carbon steel or low alloy steel Prudent Energy tropical, cold strip welding, soldering or tropical then by cold call method is made. To ensure the strength and bending test tube, metric walled pipe of universal energy and ordinary as structural components, such as shafts, or transmission fluid, for the production of thin-walled furniture, lamps, etc.
Roller tube: welded structural steel pipe or API steel pipe for belt conveyor idlers, usually with Q215, Q235A, B steel and 20 steel, diameter 63.5-219.0mm. On the tube bending, end with the vertical centerline, there are certain requirements joviality, ordinary pressure and flattening test.

Submerged Arc welded steel pipe

Submerged arc welded steel pipe: steel strip coil is as raw material, often warm extrusion molding, two-wire double-sided submerged arc welding process automatically welded spiral seam steel pipe. Submerged arc welded steel submerged arc welded pipe Features: welded pipe production process is simple, high efficiency, low cost, rapid development. The strength of the spiral welded structural steel pipe is generally higher than the Longitudinal, can narrow the billet production of large diameter pipe, you can also use the same width of the billet production of different diameters of pipe. However, compared with the same length of straight seam pipe, the weld length increased by 30 to 100%, and lower production rate. Therefore, smaller diameter pipe mostly straight seam mild steel pipe of large diameter are mostly spiral welded.

Welded steel pipe for pipeline

Pipeline is put oil,gas,water out of the ground, transported to the oil and gas industry enterprises through the carbon steel pipe including seamless pipe and welded steel pipe. With the development of the pipeline steel plate and pipe forming，welding and technological progress, and gradually expand the scope of application of the pipeline with the structural steel pipe, especially the advantages become more pronounced wet group within the distance range of large diameter pipe, in addition, the cost factors pipe,which has a dominant position in the field of line pipe, limiting the development of stainless steel seamless line pipe. Seamless line pipe production in 2004 about 400 000 t steel grade X42-70, the varieties of line pipe on land and undersea pipeline. Production of high grade steel line pipe micro-alloying heat treatment process, stainless steel seamless pipe production costs are significantly higher than the pipe, and with the improvement of the steel grade, such as the above-X80 steel grade pipeline restrictions on carbon equivalent difficult for the conventional process of seamless mild steel pipe to meet user requirements; the 12Cr1moV alloy pipe production plant in order to improve its pipeline corrosion resistance, low temperature, high-temperature environments the use of stable performance and carry out research work.

Notes of carbon steel pipe pickling

Pickling is oxide washed with hydrofluoric acid + nitric acid solution on steel surface after heated treatment. which used in the solution composition and ratio values​​: HF (3-8%), of HNO3 (10-15%), H2O (remaining amount), the processing solution temperature of 40-60 ℃. Notes of carbon stee pipe pickling process: The first point is the acceptance of incoming materials listed, specifications, quantity and straightening cutting quality, acceptance of failure to suspend pickling and timely notice of the quality inspection department or workshop. The second point is ready to work. First, in accordance with the ratio of the value of shop floor control add acid, add acid should be evenly distributed in the pickling tank, rather than add in a certain part of the acid tank; then control the size of the volume of steam to control the temperature of the acid the general control of the temperature of the acid to slightly steaming (about 60 degrees) should not control the temperature is too high and even the feeling of acid boiling; the rest is to organize the process of site steel pipe card, the distinction between different frame of steel because of the differences of steel the pickling time. The third point for the pickling process control, and also the most important step. Vary in the products, mild steel pipe and finished steel pickling and degreasing. The fourth point inspection after pickling. Finished pickling steel pipe inspection focused primarily on steel pipes inside and outside surface of the oxide cleanliness, especially the cleanliness of the bore, the best yarn Brad over inspection, sampling should be not less than 10%. Followed by inspection of the steel pipe surface acid blotting and steel color case, the test failed to re-pickling; away oil structural steel pipe surface should be no significant oil pollution, with particular attention to the steel pipe at both ends should be no residual acid outflow.

Large Diameter Piling Structural Steel Pipe

Large diameter piling structural steel pipe is more than 1000 mm diameter steel pipe, large diameter seamless steel tube is made from solid tube ingot or the perforation capillary, then through hot rolling and cold rolling or cold dial. Large-diameter coating steel pipe is in the high frequency welded pipe of large diameter spiral welded pipe and coating on the basis of plastic, the most great mouth diameter of 1200 mm, according to the needs of the different coating of polyvinyl chloride (PVC), polyethylene (PE), epoxy resin (EPOZY), and other various plastic coating performance, good adhesion and corrosion resistance is strong, can resist the corrosion of strong acid, strong alkali and other chemical, non-toxic, does not rust, wear resistance, impact resistance, resistance to permeability is strong, the pipe surface is smooth, does not adhere to any material, can reduce the transmission of resistance, improve the efficiency of traffic and transportation, reduce the pressure loss. Coating without solvent, no leakage material, so that it can't be polluted by conveying medium, so as to ensure the purity of fluid and health, in 40 ℃ to + 80 ℃ range can be used cold heat cycles, not aging, not cracking, thus it can be used in cold zone and other harsh environment.

Pile structural steel pipe manufacturing method

(1) the raw material is steel strip coil, wire, flux. Have to pass strict physical and chemical inspection before investment.

(2) the strip head to tail docking, use single or double wire submerged arc welding, after rolled steel tube adopts automatic submerged arc welding repair welding.

(3) before shaping, strip after flattening, cutting edge, edge planing, transmission and cleaning the surface to the flanging process.

 (4) on both sides of the electric contact pressure gauge control conveyor under the pressure of oil cylinder pressure, ensure the smooth delivery of strip steel.

(5) the use of external control or internal control roll forming.

(6) the weld gap control device to ensure that meet the requirements of welding seam clearance, pipe diameter, and quantity of the wrong side of weld gap are tightly controlled.

(7) welding and welding are used within the United States Lincoln welding machine for single or double wire submerged arc welding, to obtain the stable welding specification.

(8) after welding the weld passes the online continuous ultrasonic automatic meter check, ensure the spiral weld nondestructive testing coverage of 100%. If there are defects, automatic alarm and spray tags, production workers to adjust process parameters, in a timely manner to eliminate defects.

(9) by air plasma cutting machine to cut the steel tube into single.

Cut into single pole (10), after each batch of mild steel pipe in the first three root must carry on the strict inspection system, check the weld mechanical properties, chemical composition, amalgamation, steel tube surface quality and the nondestructive flaw detection, ensure that qualified pipe process, can be formally put into production.

(11) have continuous acoustic detection of weld mark parts, after manual ultrasonic and X-ray check, if there are defects, after repair, again through the nondestructive inspection, until defects have been eliminated.

(12) strip steel butt weld and fellowship with spiral weld d joint in the tube, all pass X-ray films and television inspection.

(13) each carbon steel pipe after hydrostatic pressure test, radial sealing for the pressure. Test pressure and time are controlled strictly by steel pipe hydraulic microcomputer testing device. The parameters automatically printed out.

(14) pipe end machining, make the end verticality, slope Angle and the blunt edge to get accurate control.