Pipe Application: Pipeline Transport

Pipeline transport is a mode of transportation that using steel pipe as a transport machine to transport liquid and gas materials in long distance, is a mode of transportation that transporting oil, coal and chemical products from the place of production to market, is a special component of trunk transportation in unified transport network. The cost of using pipeline to transport oil is high than that of water transport, but it is cheaper than railway transportation. Pipeline transport features to higher transportation capacity, continuous, rapid, economical, safe, reliable, smooth and less investment, less land occupied, low cost, and it can realize the automatic control. In addition to widely used in oil and natural gas long-distance transport, but also can be used in transporting ore, coal, building materials, chemicals and food.

The main pipe used in pipeline transportation is the steel pipe, in accordance with its manufacturing process can be divided into seamless steel pipe and welded steel pipe, and welded pipe can be divided into ERW steel pipe, LSAW steel pipe, spiral welded pipe, etc. According to different enviroment and diffferent application, we will select the steel pipe produced by different technology. Prime Steel Pipe are positioned as a steel pipe manufacturer and exporter for carbon steel pipe, stainless steel pipe, seamless steel pipe, welded steel pipe, steel pipe fittings, can provide all kinds of carbon steel pipe with different specifications and standards according to the requirements of customers.

The main advantages of pipeline transportation can be summarized as follows:

(1) Large capacity
An oil pipeline can continue to complete the delivery task. According to the difference of the size of the pipe diameter, its annual transport capacity can reach to several million tons or tens of millions of tons, or even more than 100 million tons.

(2) Less land occupation
Transport pipeline was usually buried in the ground, its land occupation is very small; the construction practice of transport system proved that the part of transport pipeline buried in the underground took up more than 95% of total length of the pipeline. So the permanent land occupation is very small, respectively amounts to 3% of the road and about 10% of the railway.

(3) Short construction period and low cost
A lot of practice has proved that, compared to the same traffic volume of the railway construction period, in general,the construction cycle of pipeline transportation system is shorter than 1/3.

(4) Safe and reliable, strong continuity
As the oil and gas is flammable, explosive, volatile and easy to leak, using pipeline transport is safe, and can greatly reduce the volatile loss, and the pollution caused by the leakage of air, water and soil can be greatly reduced.

(5) Little energy consumption, low cost and good efficiency
Pipeline transportation is a continuous project, the transport system does not exist no-load travel, thus the transport efficiency of system is high. Theoretical analysis and practical experience has proved the larger the diameter of the pipeline is, the farther the shipment distance is, the larger the traffic capacity is, the lower the transportation cost is. Using oil transport as an example, the transport costs ratio of pipeline transportation, water transport, rail transport is 1: 1: 1.7.

The Introduction of Spiral Steel Pipe

Spiral steel pipe, also called SSAW steel pipe or spiral welded spiral pipe, are made by hot rolled strip, it is made by extrusion forming under the normal temperature, and then welded by taking the technology of double wire and double-faced submerged-arc.

During molding process of spiral welded steel pipe, steel plate has uniform deformation and light residual stress, thus the surface has no scratches. Spiral steel pipe has more flexible thicknesses and diameters, especially in making high-grade thick pipes with small or medium aperture, these techniques has incomparable advantages in satisfying your needs.

Spiral steel pipe can be widely used in the production of large diameter spiral tubes for the following reasons:

1) as long as changing the forming angle, we can use the same width of the strip steel to produce a variety of caliber spiral pipe;
2) Since spiral welded steel pipe is formed by the continuous bending, the specified lengths of spiral steel pipe is not limited;
3) The weld in a spiral shape evenly distributed throughout the circumference of spiral steel pipe, so the dimensional accuracy of spiral pipe is high, and its strength is also high;
4) Spiral steel pipe is easy to change the size, so it is suitable for small batch and multi-species production.

Right Way to Save Spiral Pipe

Proper way to preserve spiral pipe

1) Storage space spiral steel pipe products or warehouse, should be selected in clean, smooth

drainage area, away from harmful gases or dust in factories and mines. The presence on the ground to clear the weeds and all the debris, keeping a clean steel

2) In a warehouse not with acid, alkali, salt, cement, steel and other aggressive materials stacked together. Different varieties of steel should be stacked separately, to prevent confusion, to prevent contact corrosion

3) Large steel, rail, steel disgrace, large diameter steel pipe, forgings, etc., may open dumps

4) Small and medium steel, wire rod, rebar, medium diameter steel pipe, steel wire and wire rope, etc., can be expected in a well-ventilated storage shed, but it must be the underlying thatch

5) Some small steel, sheet, strip, silicon, or thin-walled small-diameter steel pipes, all kinds of cold-rolled, cold-drawn steel products and high prices, corrosive metal products, can be stored for storage

6) A warehouse should be based on selected geographical conditions, the general ordinary enclosed warehouse, that is the roof with walls, doors and windows tight, with the Treasury ventilation device

7) Requires the Treasury sunny attention to ventilation, rain close attention to moisture, keep the appropriate storage environment

Common Defect Detection Method of Spiral Pipe

SSAW common defects magnetic particle testing or penetration testing. Spiral pipe magnetic particle testing or penetrant testing can be effectively found that surface cracks, folding, re-skin surface defects, hairline, pinholes. For ferromagnetic materials, magnetic particle testing method should be given priority, because of its high detection sensitivity; for non-ferromagnetic material, such as stainless steel spiral pipe, is used penetrant inspection method.

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Online austenitic steel spiral pipe, when the insulation is damaged or rain may have infiltrated the site, note that penetration testing to find stress corrosion cracking or pitting and other defects. However, magnetic particle or penetrant testing only on the outer surface of the pipe to detect internal defects in the surface of the powerless. The inner surface of the detector, especially crack type defect detection must be carried out by ultrasonic testing.

When the spiral pipe ends aside less resection margin, due to structural reasons detection device, spiral pipe ends head sometimes can not be effectively detected, and the end is the most likely site of the presence of cracks or other defects. If the spiral steel pipe ends there is potential for cracking tendency, weld heat affected during installation may also make potential crack. Therefore, it should be noted that after the detection of certain welded spiral steel area, to detect extended spiral steel tip defects.

Breakage of Spiral Steel Pipe

Breakage of spiral pipe according to the material after the destruction of anti-corrosion steel case and metal material is substantially the same divided into three types, namely: ① cleavage fracture, ② tie troglobites anti-fracture, ③ slip surface separation fracture.

Cleavage fracture along a section strictly crystal - product surface separating the planes called

cleavage plane. When the fracture along the crystal plane, the theoretical minimum breaking strength. Decision cleavage plane of factors specific surface energy y, the surface of the crystal plane spacing mountains and modulus of elasticity along the normal direction. Cleavage fracture with almost no plastic deformation, is a brittle fracture occurs in the body-centered cubic, hexagonal close-packed gold center. Fcc metals is generally not cleavage fracture occurs. The nature of the genus L ductile material gold sessions, shear fracture is the main fracture mechanism. Such as anti-corrosion steel alloy second phase particles to impede slippage, increasing the resistance to plastic deformation; when the plastic deformation increases, the second phase particles and the matrix interfacial peeling occurs Aung, produce tiny hole; hole formed, grew up with the merger will form a shear section. For high-purity metals, for there is no second phase particles, double metal wear-resistant composite pipe and will not yield: Health and tiny holes, the results of the battle was only shifted along the surface area is increasing, and finally the formation of slip planes separate section. Anti-corrosion steel composite spinning technology under special equipment for precise control, re-pressed wheel rotation and liner friction generates heat quickly reach the softening point of stainless steel, roller squeeze out of the outer tube is elastically deformed, the two create an interference together to achieve closely. From gold session histological point of view, it is divided into the fracture and transgranular fracture along the fracture goods.

Quality Inspection of Spiral Pipe

Spiral pipe factory should be done before the mechanical performance test and flattening test, and flaring test, and to achieve the standard requirements. Straight seam steel quality inspection method is as follows:

1, From the face of it, that is visual inspection. Visual inspection of welded joints is a simple procedure but widely used test method is an important part of product testing, the main defects and deviations are found on the surface of the weld size. Usually by the naked eye, with the standard model, gauge and test tools such as a magnifying glass. If the weld surface defects, weld defects there may be internal.

2, Physical test methods: physical test method is to use some physical phenomena assay or test method. Or within the workpiece material defect inspection, and are generally used NDT methods. NDT ultrasonic flaw detection, radiation detection, penetration testing, magnetic testing and so on.

3, Pressure vessels strength test: pressure vessels, in addition to tightness test, but also the strength test. There are common test of two hydraulic test and air pressure. They can be tested in working under pressure vessels and piping welds compactness. Hydrostatic pressure test is more sensitive than the test speed and, at the same time after the test products do not waste water treatment, drainage problems for the product is particularly applicable. But the risk is greater than the test pressure test. When tested, it must comply with the appropriate safety measures to prevent accidents during the test.

4, Compact test: liquid or gas storage vessel welding, which is not dense weld defects, such as penetrating cracks, pores, slag, incomplete penetration loose tissue and the like, can be used to find the density test. Compactness test methods are: kerosene test, carrying water testing, water will test etc.

5, Hydrostatic test: each pipe hydrostatic test should be done without leakage test pressure press Calculate P = 2ST / D where S- hydrostatic test stress test Mpa, hydrostatic test stress testing in accordance with corresponding steel standard specifies the minimum degree of yield (Q235 is 235Mpa) 60% of the selection.

How to Properly Stack Spiral Pipe

Spiral pipe stacked right help protect the quality of spiral steel pipe, spiral steel pipe prolong life, prevent deformation, erosion, so orderly stacking spiral steel pipe, but also conducive to late spiral pipe loading, inventory. Spiral Pipe buyers should also strictly in accordance with the requirements of spiral steel pipe pile.

1) Spiral pipe open dumps, following necessary pad with wood or stone, stack surface needs slightly tilted to facilitate drainage, and pay attention to the material placed flat to prevent the causing bending.

2) Spiral pipe principle requires stacking under palletizing firm to ensure the safety of the premise, to do according to species, palletizing specifications, different varieties of materials to palletizing respectively, to prevent muddy and mutual erosion, but also easy to install a library car.

3) Prohibit storage of steel aggressive action items in spiral steel pipe pile position around.

4) Spiral steel pipe pile bottom should be padded, strong, smooth, prevent moisture or material deformation,

5) The same material by successively respectively stacking storage.

6) Sspiral steel stacking height, artificial homework does not exceed 1.2m, mechanical homework does not exceed 1.5m, stack no larger than 2.5m,

7) Be left between the stacks and stacks of certain passages, check road is generally O. 5m, of access depending on the size and material transport machinery, generally is 1.5 ~ 2.0m,

8) Open dumps angles and channels should stoop to put that mouth down, beam shall stand up, you can not be up and groove steel to avoid rusting water.

9) The end of booster stack, if the warehouse sunny cement floor, to elevate O.1m, if the mud shall booster O.2 ~ 0.5m. If it is open space, concrete floor booster 0.3 to 0.5 m, the surface mud booster 0.5 ~ 0.7m.

Spiral Welded Pipe Classification

Spiral Welded Pipe can be applied in different area. Generally, it is widely applied for fluid service, ordinary structure, line pipe and casing. In the steel industry, we classified different steel pipe standards for different application. For detailed classification, please see the table below:

  

Classification	Standard	Main Products
1. Spirl Welded Pipe for Fluid Service	GB/T 14291	Welded pipe for mine fluid sevice
	GB/T 3091	Welded pipe for low pressure fluid service
	SY/T 5037	Spirally submerged arc welded steel pipe for pipelines for low pressure fluid service
	ASTM A53	Black and hot-hipped galvanized welded and seamless steel pipe
	BS EN10217-2	Welded steel tybes for pressure purposes - delivery technical conditions - part2: Electric welded non- alloy and alloy  steel tubes with specified elevated temperature properties
	BS EN10217-5	Welded steel tybes for pressure purposes - delivery technical conditions - part5: submerged arc welded non-alloy  and alloy steel tubes with specified elevated temperature properties
2. Spiral Welded Pipe for Ordinary Structure	GB/T 13793	Longitudinally electric resistance welded steel pipe
	SY/T 5040	Spirally submerged arc welded steel pipe piles
	ASTM A252	Welded and seamless steel pipe piles
	BS EN10219-1	Cold formed welded structural hollow sections of non-alloy and fine grain steels - part1: Technical delivert  conditions
	BS EN10219-2	Cold formed welded structural hollow sections of non-alloy and fine grain steels - part2: tolerances dimmsions and  sectional properties
3. Spiral Welded Pipe for Line Pipe	GB/T 9711.1	Steel pipe for pipeline transportation system of petroleum and natural gas industries(Class A steel pipe)
	GB/T 9711.2	Steel pipe for pipeline transportation system of petroleum and natural gas industries(Class B steel pipe)
	API 5L PSL1/2	Line pipe
4. Spiral Welded Pipe for Casing	API 5CT/ ISO  11960 PSL1	Steel pipe for use as casing or tubing for wells of petroleum and natural gas industries