Shenzhen Shengjinlong Iron and Steel Co., Ltd.

0755-89345123

215088612@qq.com

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Shenzhen Shengjinlong Iron and Steel Co., Ltd.


Contact: Mr. Wu


Contact number: 0755-89345123


Mobile: 13682609066


E-mail: 215088612@qq.com


Address: No. 06, Building A, Building Materials Market, Pingshan New District, Shenzhen


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Steel pipe knowledge

First, the classification of steel pipes
1. Classification according to production methods (1) Seamless steel pipe--hot rolled pipe, cold rolled pipe, cold drawn pipe, extruded pipe, top pipe (2) welded pipe (a) according to process - arc welded pipe, electric resistance welded pipe ( High frequency, low frequency), gas welded pipe, furnace welded pipe (b) by weld seam - straight seam welded pipe, spiral welded pipe
2, according to the shape of the section classification (1) simple section steel pipe - round steel pipe, square steel pipe, elliptical steel pipe, triangular steel pipe, hexagonal steel pipe, diamond steel pipe, octagonal steel pipe, semi-circular steel circle, other (2) complex Section steel pipe--unequal hexagonal steel pipe, five-petal plum-shaped steel pipe, double convex steel pipe, double concave steel pipe, melon-shaped steel pipe, conical steel pipe, corrugated steel pipe, case steel pipe, others
3, according to wall thickness classification - thin-walled steel pipe, thick-walled steel pipe
4. Classification by use--Pipeline steel pipe, thermal equipment steel pipe, machinery industrial steel pipe, petroleum, geological drilling steel pipe, container steel pipe, chemical industry steel pipe, special purpose steel pipe, others

Second, welded steel pipe standard welded steel pipe, also known as welded pipe, is a steel pipe made of steel or steel strip after crimp forming. The welded steel pipe has simple production process, high production efficiency, many varieties and specifications, and less equipment, but the general strength is lower than that of seamless steel pipe. Since the 1930s, with the rapid development of high-quality strip continuous rolling production and the advancement of welding and inspection technology, the quality of welded joints has been continuously improved, the variety specifications of welded steel pipes have been increasing, and more and more fields have replaced Seam steel pipe. Welded steel pipes are divided into straight welded pipes and spiral welded pipes in the form of welds.

Straight seam welded pipe has simple production process, high production efficiency, low cost and rapid development. The strength of the spiral welded pipe is generally higher than that of the straight welded pipe. It is possible to produce a welded pipe with a larger diameter by using a narrow blank, and it is also possible to produce a welded pipe having a different pipe diameter with a blank of the same width. However, compared with the straight pipe of the same length, the weld length is increased by 30 to 100%, and the production speed is low.
Therefore, most of the smaller diameter welded pipes are straight seam welded, and the large diameter welded pipes are mostly spiral welded.

1. Welded steel pipe for low-pressure fluid transportation (GB/T3092-1993) is also called general welded pipe, commonly known as black pipe. It is a welded steel pipe for conveying general low pressure fluids such as water, gas, air, oil and heating steam and other purposes. The thickness of the steel pipe is divided into ordinary steel pipe and thick steel pipe; the pipe end form is divided into non-threaded steel pipe (light pipe) and threaded steel pipe. The specification of the steel pipe is expressed by the nominal diameter (mm), and the nominal diameter is an approximate value of the inner diameter. It is customary to use inches, such as 11/2. The welded steel pipe for low-pressure fluid transportation is mainly used as a raw pipe for galvanized welded steel pipe for low-pressure fluid transportation, in addition to being directly used for conveying fluid.
2. Galvanized welded steel pipe for low pressure fluid transportation (GB/T3091-1993) is also called galvanized electric welded steel pipe, commonly known as white tube. It is a hot dip galvanizing (furnace welding or electric welding) steel pipe for transporting water, gas, air oil, heating steam, warm water and other general low pressure fluids or other purposes. The thickness of the steel pipe is divided into ordinary galvanized steel pipe and thick galvanized steel pipe; the connection end form is divided into non-thread galvanized steel pipe and threaded galvanized steel pipe. The specification of the steel pipe is expressed by the nominal diameter (mm), and the nominal diameter is an approximate value of the inner diameter. It is customary to use inches, such as 11/2.
3. Ordinary carbon steel wire casing (GB3640-88) is a steel pipe used to protect electric wires in electrical installation projects such as industrial and civil construction, installation machinery and equipment.
4. Straight seam electric welded steel pipe (YB242-63) is a steel pipe whose weld is parallel to the longitudinal direction of the steel pipe. Usually divided into metric electric welded steel pipe, welded thin-walled pipe, transformer cooling oil pipe and so on.
5. Spiral-slot submerged arc welded steel pipe (SY5036-83) for pressure-bearing fluid transportation is a hot-rolled steel strip coil for tube blank, which is often spiral-formed and welded by double-sided submerged arc welding for pressure fluid transportation. Spiral seam steel pipe. The steel pipe has strong pressure bearing capacity and good welding performance. After various strict scientific tests and tests, the safety can be used*. The steel pipe has a large caliber, high conveying efficiency, and can save investment in laying pipelines. It is mainly used to transport oil and natural gas pipelines.
6. Spiral seam high-frequency welded steel pipe (SY5038-83) for pressurized fluid conveying is a hot-rolled steel strip coil for tube blank, which is often spiral-formed by high-frequency lap welding for pressure fluid transport. Spiral seam high frequency welded steel pipe. The steel pipe has strong pressure bearing capacity and good plasticity, which is convenient for welding and processing. After various strict and scientific inspections and tests, the use of safety can be *, the steel pipe has large caliber, high conveying efficiency, and can save investment in laying pipelines. It is mainly used for laying pipelines for transporting oil and natural gas.
7. General Spiral Seam Submerged Arc Welded Steel Pipe (SY5037-83) for low-pressure fluid transportation is made by hot-rolled steel strip coil, which is often spiral-formed by double-sided automatic submerged arc welding or single-sided welding. Submerged arc welded steel pipes for general low pressure fluid transportation such as water, gas, air and steam.
8. General high-pressure fluid conveying spiral spiral high-frequency welded steel pipe (SY5039-83) is a hot-rolled steel strip coil for tube blank, regular temperature spiral forming, high-frequency lap welding welding for general low-pressure fluid conveying spiral High-frequency welded steel pipe.
9. Spiral welded steel pipe (SY5040-83) for piles is made of hot-rolled steel strip coils, often spiral-formed by double-sided submerged arc welding or high-frequency welding, used for civil engineering structures, wharfs and bridges. Steel pipes for foundation piles.
The steel-plastic composite pipe and the large-diameter coated steel-steel-plastic composite pipe are made of hot-dip galvanized steel pipe as the base material, and the powder is melt-sprayed by the powder coating technology on the inner wall (when the outer wall is required), and the performance is excellent. Compared with galvanized pipe, it has the advantages of corrosion resistance, no rust, no fouling, smooth and smooth, clean and non-toxic, and long service life. According to tests, the service life of steel-plastic composite pipes is more than three times that of galvanized pipes. Compared with plastic tubes, it has the advantages of high mechanical strength, good pressure resistance and heat resistance. Since the substrate is a steel pipe, there is no problem of embrittlement or aging. It can be widely used in fluid transportation and heating projects such as tap water, gas, chemical products, etc. It is an upgraded product of galvanized pipe. Because the installation and use method is basically the same as the traditional galvanized pipe, the pipe fittings are also the same in form, and can replace the aluminum-plastic composite pipe to play a role in the large-diameter tap water transportation. It has been well received by users and has become the most competitive in the pipeline market. One of the new products.
The coated steel pipe is made of plastic coated on the basis of large-diameter spiral welded pipe and high-frequency welded pipe. The maximum pipe diameter is up to 1200mm. It can be coated with polyvinyl chloride (PVC), polyethylene (PE) and epoxy according to different needs. Resin (EPOZY) and other plastic coatings with different properties, good adhesion, strong corrosion resistance, strong acid, alkali and other chemical corrosion resistance, non-toxic, non-corrosive, wear-resistant, impact-resistant, strong penetration resistance The surface of the pipe is smooth and does not adhere to any substance, which can reduce the resistance during transportation, increase the flow rate and transportation efficiency, and reduce the transmission pressure loss. The coating has no solvent and no exudable substances, so it will not pollute the medium to be transported, thus ensuring the purity and hygienicity of the fluid. It can be used alternately between -40 ° C and +80 ° C in the range of hot and cold cycles, without aging, It does not crack and can be used in harsh environments such as cold areas.
Large diameter coated steel pipes are widely used in tap water, natural gas, petroleum, chemical, pharmaceutical, telecommunications, electric power, marine and other engineering fields.