2、the cross-sectional shape
（1）Section pipe -- simple circular pipe, square steel tubes, oval-shaped pipe, triangular steel pipe, pipe hexagon, diamond pipe, pipe-shaped 1.80, semicircular steel round Other
（2）complex pipe sections -- ranging from border hexagonal steel pipe, pipe penta cinquefoil. Pipe double convex, double concave steel pipe, pipe-shaped hull, conical steel pipe, corrugated steel pipe, pipe supracrustal other

3、wall thickness, thick tube

4、category by used -- Pipeline pipe, the pipe thermal equipment, industrial machinery pipe, oil, geological drilling pipe, pipe containers, chemical industrial pipe, a special purpose pipe, the other
二、second . Welded Pipe Standard
　welded pipe is after curly strip or plate is made of welded steel pipe after molding. Welded steel pipe production process is simple, efficient, the varieties of different specifications, fewer capital equipment, but the general strength seamless steel pipe. Since the 20th century, the 1930s, with the rapid development of high-quality strip rolling and welding and testing technology, Weld continually raising the quality of the welded steel pipe specifications growing varieties, and in an increasing number of areas instead of seamless steel pipe. By welded steel pipe weld in the form of longitudinal welded pipe and spiral welded pipe.
　Longitudinal welded pipe production process is simple, high efficiency, low cost and rapid development. SSAW intensity than the longitudinal welded pipe, use a narrow pipe of larger diameter billet production. can also use the same width of the pipe diameter billet production. But with the same length of the straight tube, the weld length 30~100%, but lower production rate.
Therefore, the smaller diameter pipe used mostly straight seam welding, mostly using large diameter spiral welded pipe.
　　1.Low-voltage transmission fluid welded tube (GB/T3091-2001) also claimed that the general pipe. called twin. It is used to transport water, gas, air and steam heating oil and other generally low fluid pressure in the welded steel pipe and other uses. Ordinary pipe and then into thick pipe wall thickness of pipe; Take over the terminal is divided into non-screw steel pipes (tubes) and a screw steel pipes. Nominal diameter pipe used in the specifications (mm), the nominal diameter of the aperture is approximation. Common inch habits, such as 11/2. Low-voltage transmission fluid addition of welded steel pipe for direct transmission fluid, also for a large number of low-pressure fluid delivery tube with the original galvanized welded steel pipe.
　　2.Low-voltage transmission fluid Galvanized welded pipe (GB/T3091-2001) also claimed galvanized welded steel pipe. commonly known as white pipe. It is used to transport water, gas, heating oil and steam air. The heated fluid or other general purpose of the low-pressure welding hot dip galvanized (furnace welding or welding) pipe. Pipe wall thickness into ordinary galvanized pipe, and then the thicker galvanized pipe; form into takeover end with a non-threaded galvanized pipe threaded galvanized pipe. Nominal diameter pipe used in the specifications (mm), the nominal diameter of the aperture is approximation. Common inch habits, such as 11/2.
　　3.Ordinary carbon steel wire casing (GB3640-88) is the industrial and public buildings. installation of machinery and equipment used for the installation of electrical wire to protect the pipe.
　　4.Longitudinal welded steel pipe (YB242-63) is parallel to the longitudinal weld pipe and pipe. Usually divided into metric welded steel pipe and tube welding electrodes, transformer cooling tubing and so forth.
　　5.Transmission fluid pressure spiral submerged arc welded pipe (SY5036-83) the volume of hot rolled strip for the tube. Regular temperature spiral shape, with double-SAW welding method for the transmission of fluid pressure SSAW pipe. Pipe-bearing capacity, good weldability, after all strictly scientific examination and testing, the use of safe and reliable. Pipe diameter, transportation efficient and economical laying pipeline investment. Mainly used for transportation of oil and natural gas pipelines.
　　6.Pressure Fluid Transport SSAW Welded Pipe (SY5038-83) the volume of hot rolled strip for the tube. Regular temperature spiral shape, lap welding method using high frequency welding, the transmission fluid pressure for high-frequency spiral welded pipe joints. Pipe-bearing capacity, plastic, welding and easy to process; After all strict and scientific examination and testing. the use of safe and reliable, pipe diameter, high transmission efficiency, while saving the laying of pipeline investments. Used to upgrade transportation of oil, natural gas pipeline.
　　7.Low-voltage transmission fluid ordinary spiral submerged arc welded pipe (SY5037-2000) the volume of hot rolled strip for the tube. Regular temperature spiral shape, using single or double SAW automatic welding into the legal system for water, gas, Air and steam with the general low-voltage transmission fluid SSAW.
　　8.Low-voltage transmission fluid normally used SSAW Welded Pipe (SY5039-83) the volume of hot rolled strip for the tube. Regular temperature spiral shape, using high-frequency welding lap welding method used for general low-voltage transmission fluid Spiral Welded Pipe joints.
　　9．Spiral weld pipe piling (SY5040-2000) the volume of hot rolled strip for the tube. Regular temperature spiral shaped, double submerged arc welding or using high-frequency welding products for the civil engineering structure, a pier, Pipe pile bridges and other infrastructure.
Third, seamless steel pipe standard "is a hollow section BR>, not peripheral joints of long steel. Hollow steel pipe with large pipelines for the transmission fluid, transmission oil, gas, gas, and certain solid materials such as water pipes. Solid steel bar and steel, etc., in the same flexural torsional strength, lighter weight, it is a cross-section steel. Structure and widely used in the manufacture of mechanical parts, such as oil drill pipe, automotive transmission. Zihengjujia used in the steel and construction scaffolding. Pipes Ring parts manufacturers can improve material utilization and simplify manufacturing processes, materials and processing time saving. Races such as rolling bearings, steel sets and so on, has been widely used to manufacture pipe. Pipe indispensable materials or conventional weapons, a barrel, the barrel of a gun so to have pipe manufacturing. Cross sectional area can be divided into different shapes by the Pipe and Tube Special Pipes. As conditions in the same perimeter, the largest area round with a circular tube can be delivered more fluid. In addition, the radial ring section in the internal or external pressure to bear that load more evenly, so that the overwhelming majority of tube pipe.
　However, there are certain limitations tube, such as by bending conditions, the better side on the tube. rectangular tube bending strength, some form of framework, steel and wood furniture on the common side rectangular pipe. Need to use any other cross-section of different shapes variant pipe.
　　1.Seamless structure (GB/T8162- 1999) is the seamless steel tubes for general structure and mechanical structures.
　　2.Seamless transmission fluid (GB/T8163-1999) is used for transmission of water, oil, natural gas and other fluids generally seamless steel pipe.
　　3.Seamless low and medium pressure boiler (GB3087-1999) structure is used in the manufacture of various low and medium pressure steam boiler superheater tube. possession of boiling water and superheated steam locomotive boiler tube, opium possession. Kobata brick arch effective management and quality hot-rolled carbon steel and drawing (rolling) seamless steel pipe.
　　4.High Pressure Boiler Seamless (GB5310-1995) is used in the manufacture of high-pressure water pipe above the boiler heating surface quality carbon steel. steel and stainless steel seamless pipe heat.
　　5.Fertilizer equipment used high-pressure seamless steel pipe (GB6479-2000) is applicable to temperature -40~400 ℃. 10~30Ma pressure for the chemical equipment and pipe-quality carbon steel and alloy steel seamless pipe.
　　6.Seamless oil cracking (GB9948-88) is applicable to oil refineries in the tube. seamless steel tube and pipe heat exchangers.
　　7.Geological drilling pipe (YB235-70) for the use of the geological department core drilling pipe. end-use can be divided into drill pipe, drill collar, the core tube, precipitation, etc., and the casing.
　　8.Seamless diamond core drilling (GB3423-82) for diamond core drilling in the drill pipe. Core bar, seamless steel pipe casing.
　　9.Oil drilling pipe (YB528-65) for oil drilling ends within or outside thickening of the Seamless Steel Tube thickened. Pipe Threading two buses and silk, silk effective joints linking cars, trucks and silk useful tool for welded joints integrated approach.
　　10.Ships carbon steel seamless pipe (GB5213-85) I class ship is creating pressure piping systems. grade pressure piping systems, carbon steel seamless pipe in the boiler and overheating transparencies. Carbon steel seamless pipe wall temperature does not exceed 450 ° C, the temperature over 450 ° C alloy seamless steel pipe wall.
　　11.Seamless automobile axle housing (GB3088-82) is the axle housing and car driven Bridge shell axis effective quality hot-rolled carbon steel and alloy steel seamless steel pipe.
　　12.Diesel used high-pressure tubing (GB3093-2002) is to create effective drawing Diesel injection system pressure seamless steel pipe.
　　13.Hydraulic and pneumatic cylinder diameter seamless pipe used precision (GB8713-88) manufacturing hydraulic and pneumatic cylinder is used with precision or cold precision seamless steel pipe diameter size drawing.
　　14.Drawing or cold precision seamless steel pipe (GB3639-2000) for mechanical structures, Hydraulic Equipment good surface finish and dimensional accuracy of high precision cold-rolled seamless steel pipe or drawing.
Seamless steel pipe manufacturing structure or use sophisticated hydraulic equipment, could lead to significant savings in machining hours. improve material utilization, which will also help improve the quality of their products.
　　15.Seamless Stainless Steel Structural Tubes (GB/T14975-2002), which is widely used in chemical industry, oil, as well, medical, food, machinery and other industrial pipeline corrosion resistance and structural components made of stainless steel and hot rolling (squeeze. expansion) and drawing (rolling) seamless steel pipe.
　　16.Fluid Transport stainless steel seamless pipe (GB/T14976-2002) for the transmission fluid is made of stainless steel and hot-rolled (squeeze. expansion) and drawing (rolling) seamless steel pipe.
　　17.Heterotypic seamless steel pipe section is in addition to other forms of seamless steel pipe pipe outside the skies. By the shape and size of the pipe section can be divided into different thickness and other heterotypic Seamless Steel Tube (codenamed D). heterotypic seamless steel pipe wall thickness range (codenamed BD), the variable-diameter seamless pipe heterotypic (codenamed BJ). Heterotypic pieces of seamless steel pipe for a wide structure, tools and mechanical parts. Pipe and, in general, Special Pipes greater moment of inertia and section modulus, a greater bending resistance capacity, can greatly reduce the structural weight savings steel.
Plastic pipe, large diameter pipe coating steel-plastic composite pipe for a hot-dip galvanized steel pipe matrix. After spraying powder melting in the wall (wall may need) plastic coating, is high performance. And galvanized tubes, corrosion resistance, corrosion, Scale, smooth smooth, clean drug-free, long life and other advantages. According to tests, the service life of galvanized steel-plastic composite pipe controls more than three-fold. Compared with the plastic pipe, has high mechanical strength, pressure, heat-resistance and other advantages. Pipe is due to the matrix, there is no brittleness problem of aging. Can be widely used in water supply, gas, chemical products such as fluid transportation and heating project is the upgrading of management galvanized products. Since its installation with the traditional galvanized the same tube, pipe forms are identical, AL-PE composite pipes in but can replace large diameter water transmission play a role, popular with users. Pipeline market has become one of the most competitive new products.
In the large diameter pipe coating and high frequency spiral welded pipe from plastic pipe coating basis, the largest pipe diameter 1200mm, according to the needs of different coated polyvinyl chloride (PVC). Polyethylene (PE), epoxy resin (EPOZY) different properties of plastic coating adhesion, strong corrosion resistance, acid resistance, alkali and other chemicals corrosive, non-toxic, non-corrosion, abrasion resistance, impact resistance, strong penetration resistance. Pipeline smooth surface, adhesion any material, which can reduce transmission of resistance, improve traffic flow and transportation efficiency. pressure to reduce transmission losses. Solvent-free coating, it is leaking material, thus no pollution transmission medium, thus ensuring the purity and health fluid, -40 ° C to +80 ° C temperature range can be used in turn to recycling, aging, fragmented, there will be a cold zone in the harsh environment use.
Large diameter pipe coating widely used tap water, natural gas, petroleum, chemical industry, medicine, communications, electricity, marine engineering field.