Turning to the pipe material, seamless pipe should be is very common a, and common species of pipeline materials comparison, the pipe seamless characteristics, let seamless pipe, the use of large area in pipeline transportation, pipeline transportation is a new mode of transport, the transport energy savings from a certain extent, at the same time, this type of pipe materials often quality is also superior to. Therefore, in the pipeline transportation, this type of material is very common.

Seamless pipe is the main characteristic of superior quality, in the use of seamless pipe for pipeline transport at the same time, can effectively prevent the leakage of the situation occurred, in general, this type of pipe material is very good. Seamless pipe in the price also has an advantage, the price is seamless access to market a key factor, using professional materials to build, seamless pipe in the factory before they are able to professional quality testing, reputation so that they can better guarantee the pipeline materials, used in the market more at ease.

Thermal casing heat shrink tubing, insulation, heat resistance, heat shrink tubing is a special polyolefin heat-shrinkable tubing material, but also called the EVA material. It has a soft and flexible. Heat (70-90 degrees) will shrink, widely used in a variety of wiring harness, solder joints, inductor insulation, metal pipes, rods rust and corrosion. Electrical equipment stores sell, as big business wire Dianliao sub shop has commonly used in wire connectors, choose the right heat shrink tubing, set in the wire connectors, heating with a hot air gun, heat shrink tubing shrink, put joint stuck with thermal casing features

Generally with electronics, electrical appliances, batteries, packaging insulation effect

By using the hot air can make it tight, play insulation, protection and other functions

Heat shrinkable sleeve heated by something

Hair dryer, hot air, shrinking machine can be.

The role of thermal casing

Heat shrink tubing is a heat shrinkable packaging material that is exposed to heat shrinkage, according to the material can be divided into pvc heat shrinkable sleeve, pet thermal casing, irradiation crosslinked pe heat shrink tubing, 10KV high-voltage busbar protection heat shrink tubing, 35KV high-voltage busbar protection heat shrink tubing, with plastic double-wall heat shrink tubing, heat shrinkable sleeve imitation wood

Thermal casing material or what kind of heat shrink tubing material is mainly plastics, including PVC, ABS, EVA, PET, etc.

Welded steel pipes used in billet steel sheet or strip, its different welding process is divided into the furnace pipe, welded (ERW) pipes and automatic arc welded pipe. Because of the different forms of welding is divided into two kinds of Longitudinal and spiral welded pipe. Its end shape is divided into circular pipe and shaped (square, flat, etc.) pipe. Welded pipes of different materials and its use is divided into the following varieties:

1, GB / T3091-1993 (low pressure fluid delivery galvanized welded steel pipe). Mainly used for conveying water, gas, air, oil and heating hot water or steam generally lower pressure fluid and other uses tubes. The representative of material Q235A grade steel.

2, GB / T3092-1993 (low pressure fluid delivery galvanized welded steel pipe). Mainly used for conveying water, gas, air, oil and heating hot water or steam generally lower pressure fluid and other uses tubes. The representative material for: Q235A grade steel.

3, GB / T14291-1992 (mine fluid delivery welded steel pipe). Mainly used for mine air pressure, drainage, gas discharge axis with straight seam welded steel pipe. The representative of material Q235A, B grade steel. GB / T14980-1994 (low pressure fluid with large-diameter welded steel pipe). Mainly used for conveying water, sewage, gas, air, and other low pressure steam heating fluid and other uses. The representative of material Q235A grade steel.

4, GB / T12770-1991 (mechanical structure with stainless steel welded pipe). Mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical components and structures. The representative of material 0Cr13,1Cr17,00Cr19Ni11,1Cr18Ni9,0Cr18Ni11Nb like.

5, GB / T12771-1991 (fluid transport stainless steel welded pipe). Mainly used to transport low pressure corrosive media. Representative material for 0Cr13,0Cr19Ni9,00Cr19Ni11,00Cr17,0Cr18Ni11Nb, 0017Cr17Ni14Mo2 like.

API5L seamless steel pipe production technology: seamless steel tube is mainly through the tension reducing diameter to complete, Zhang Lijian sizing process is hollow base material without mandrel continuous rolling process.

(API5L seamless steel pipe: in order to ensure the parent pipe welding quality conditions, pipe tension reducing process is to pipe the whole heating to 950 degrees Celsius above, and then the tension reducing mill stretch reducing mill a total of 24 times) rolled into a variety of diameter and wall thickness of the finished pipe, the use of this technology produced hot-rolled steel and ordinary high-frequency welded pipe has essential distinction by heating furnace after heating the weld and parent microstructure and mechanical performance can be reached completely consistent in addition, through multi pass tension reducing mill rolling and automatic control of the pipe size accuracy (especially the tube body roundness and wall thickness accuracy) is better than the same seamless tube. Developed countries of the world production of fluid pipe, boiler tube has been widely used in the process of welded pipe seamless, along with the development of society, the domestic hot-rolled pipe gradually replace seamless pipe, the situation has been formed. Seamless steel pipe prices better than straight seam welded pipe is about high 200-500 yuan / ton, while the seamless steel pipe price than the price of seamless steel pipe and high 800-1200 yuan / ton.

Spiral Pipe degaussing method

1, with a coil wound pipe outside, to the coil through the AC, alternating current gradually decreases until it is reduced to zero. Degaussing Results: Does not change the physical properties of spiral steel pipe, however, in the event of an external magnetic field again, spiral steel pipe will be magnetized.

2, through the heat treatment process can be more thorough degaussing, however, after degaussing, spiral steel hardness and rigidity are subject to change, and then encountered when the applied magnetic field, magnetic field disappeared after the steel pipe will be substantially no residual magnetism in the future.

3, the heat treatment process, probably: anaerobic heated to a certain temperature, and then, with 72 hours to cool slowly to room temperature.

Cause of the magnetic field to produce spiral steel pipe

In the welding process, the welding DC welding, the welding horn and a big line positions due to the large current, generate a strong magnetic field, steel tube under the action of the magnetic field, the magnetic moments tend to acquire or to obtain the same magnetic field arrangement direction. When the end of welding, the magnetic field gradually reduced until it disappears, because the hysteresis in the tube as well as the presence of residual magnetic flux density, which is what we usually refer to the residual magnetism phenomenon.

Hazard spiral steel field

The existence of residual magnetism, image intensifier electron beam is deflected, X-ray image generation television system "S" type distortion, affecting the pores, slag and other natural defects, especially the lack of penetration, cracks and other defects in the linear nature detection rate.

As the impact of pipeline stages to improve the image intensifier and X-ray television systems change type, especially remanence. The existence of residual magnetism when the pipeline butt welding ring, will have partial arc phenomenon, affecting the quality of welding, the presence of residual magnetism seriously affected the quality of construction.

Pipe welding pipe, also known as pipe, is a steel plate or strip after the coil formed by welding made of steel. Welding steel pipe production process is simple, the production efficiency is high, the variety of specifications, equipment and less capital, but the general strength is lower than the seamless steel pipe. Since the thirties of the 20th century, with the rapid development of high quality cold rolling strip steel rolling production and progress of welding and inspection technology, continuously improve the quality of weld, welding steel pipe specifications are increasing and in more and more fields instead of the seamless steel pipe. According to the form of welded steel pipe weld is divided into longitudinal and spiral welded pipe.

Welded steel pipe is used as a steel plate or strip, because of its welding process is divided into furnace pipe, welding (resistance welding) pipe and automatic arc welded pipe. Because of the different forms of welding longitudinal and spiral welded into two. Because of its end shape is divided into circular welded pipe and shaped (square, flat, etc.) welded pipe. Welded pipe is divided into the following several varieties because of its material and use:

GB/T3091-2001 (galvanized welded steel pipe for low pressure fluid delivery). Mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low pressure fluid and other use pipe. Its representative material is: Q235 grade a steel.

GB/T14291-2006 (mineral fluid transport welded steel pipe). Mainly used in mine air pressure, drainage, gas drainage shaft with a straight seam welded steel pipe. Its representative material B, Q235A grade steel. GB/T14980-1994 (large diameter welded steel pipe for low pressure fluid delivery). Mainly used for conveying water, sewage, gas, air, heating steam and other low pressure fluid and other purposes. Its representative material Q235 grade a steel.

GB/T12770-2002 (stainless steel welded pipe for mechanical structure). Mainly used in machinery, automobiles, bicycles, furniture, hotels and hotel decoration and other mechanical components and structural parts. Its representative material 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc..

GB/T12771-1991 (fluid transport with stainless steel welded pipe). Mainly used for conveying low pressure corrosive medium. Representative material for 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc..

Teflon casing pipe is polytetrafluoroethylene resin extruded products can be high temperature, wear resistance, corrosion resistance, non-stick weathering characteristics. Depending on the product and the wall thickness of the withstand voltage level can be divided into the Teflon sleeve S-type, T-type and L-type three.

Teflon casing pipe, also known as polytetrafluoroethylene (PTFE) tube, is the first use of polytetrafluoroethylene (PTFE) made of a material. High temperature (260 ℃), corrosion resistance, high insulation, have excellent electrical properties.

Teflon casing pipe is made of Teflon resin dispersed in an organic solvent at room temperature to push the extrusion aid was suppressed, and then by drying, sintering. Can be divided into two kinds according to the diameter size of the capillary tube and HOSE. hose tube diameter> 4mm, capillary diameter ≤4mm.

The product has excellent dielectric properties and chemical resistance, high temperature, high pressure, non-absorbent, non-stick, non-conductive, low friction coefficient and non-aging properties. Widely used in transformers, electrical appliances, communications equipment, chemical fluid, machinery manufacturing, medical equipment and automotive aerospace and other fields.

parameter

Voltage: 150V-600V

Working temperature: -65 ℃ + 260 ℃

Melting point: 327 ℃

Flame retardant: VW-1

Breakdown strength: 45KV / mm

Color: transparent, black, blue, red, yellow, green

1. Product Specifications:

Pipe diameter: Ф406.4 ~ Ф1422.4mm (16-56in)

Pipe length: 3 ~ 12.5m

Wall thickness: Carbon, low-carbon alloy production in the range of 8 ~ 50mm;

X70 steel grade than carbon steel alloy wall thickness of up to 6.4-26.4mm (0.252--1.04in)

Product Standard: SO3183, API Spec 5LI, API Spec 2B, GB / T9711 and other standards

Yield: annual output of large diameter submerged arc welded pipe 150,000 tons

2. Uses:

Mainly used for land, marine oil and gas. Transportation and offshore platforms coal slurry, pulp and other media, power plants, chemical and urban structural tube.

3. main feature:

After overall mechanical expanding process. Pipe internal stress is small and uniformly distributed. Can effectively prevent stress corrosion cracking. High dimensional accuracy. Easy on-site welding construction.

Using pre-finish welding process after welding. Welding process is stable. High weld quality.

Weld is easy to realize the production process of non-destructive testing and use in the field of non-destructive testing review.

And non-straight seam welded pipe compared. Short welds, small probability of welding defects.

Great specifications. Can produce small-diameter, thick wall also produces large-diameter, thick-wall steel pipe.

Natural gas pipeline is a natural gas (including gas from oil production) mining or processing factory pipelines to the city gas distribution center or industrial enterprise users, also known as gas pipeline. Natural gas pipeline transportation of natural gas, is the only way to transport a large number of natural gas on the land. In the world's total length of pipelines, natural gas pipelines accounted for about half of the.

Structure characteristics

pipeline structure

The gas pipeline is composed of a single tube by connecting together. The modern gas collecting pipe and the gas transmission pipeline are formed by the connection of the steel pipe through electric welding. Steel seamless tube, spiral seam pipe, straight seam pipe, seamless pipe for pipeline diameter is 529 mm below the spiral seam pipe and straight pipe for large diameter pipeline. In the pipe cross section structure pipeline, complex for internal coating of steel - insulation layer insulation (insulation layer); only simple steel tube and the outer insulating layer, and the inner wall coating and heat (cold) layer are considered gas process coupled with determination.

Piping material

Steel pipe is the main material of pipe. Natural gas transmission steel pipe is the plate (with) through the deep processing of the formation of a special metallurgical products. The structure of pipeline steel, due to the difference of the process technology, there are some differences in the production of pipeline steel. In 1960s, the general use of X52 steel, in 70s the use of X60, X65 steel, X70 steel based 80-90. Foreign gas pipelines have begun to use X80 steel. With the continuous development of pipeline steel research, Canada and other countries have laid the test section of X100 and X120 pipeline steel. For the first time, the X80 grade pipeline steel was used in the test section of the 7.71km for the first time in the pipeline project of the contact line. Up to 4843km of the west east gas pipeline pipeline all used a diameter of X80 1219mm steel grade pipeline steel, the gas pressure increased to 12Mpa. Generally speaking, X80 steel is ferrite and bainite dual phase structure, X100 pipeline steel is bainite microstructure, X120 pipeline steel is ultra low carbon bainite and martensite. Strength, toughness and weld ability are the three most basic quality control indexes for the pipe of natural gas pipeline [4].

Pipeline characteristics

1. The gas transmission pipeline system is a continuous closed transmission system.

2. From transportation, storage to the user, the gas is in a state of pressure.

3. The transportation of natural gas proportion is small, the static head effect is far less than the liquid, the design height less than 200 meters, the static head is negligible, the line is almost not affected by the vertical limit of the terrain.

4. Does not exist in the liquid pipeline water hammer damage.

5. When the accident occurred, the harm is big, and the scope is wide. Once the rupture of the pipeline, the release of energy, long tear length, discharge of natural gas in case of fire, but also easy to cause a fire.