Today it is difficult to imagine the world and one’s own life without the achievements of science and technology. Many believe that the main achievement is information development. But just imagine your life without industrial facilities! In everyday life, everyone enjoys the benefits of civilization: water, electricity, gas, heat - and can no longer imagine their comfortable life without them. In order to deliver water and gas, water and gas pipelines are built, which act as a vehicle.
When installing, builders use pipes for gas pipelines. It is important to note that they have entered our daily lives and have taken a crucial position as an inexpensive means of delivering liquids and gases.
What is a pipe?
There is currently no single answer to this question. In general, we can say that the pipe is an industrial product of a hollow profile, which is used to transport gas, oil, various fluids, insulation, reinforcement.
Pipe classification
Seamless pipes are rolled (hot and cold rolling), pressed (diameter up to 820 mm) and cast (cast iron and steel, diameter up to 900 mm).
According to the section profile, shaped, round are distinguished:
• Square.
• Rectangular.
• Oval.
• Segmented.
• Ribbed.
• Teardrop-shaped.
• Six-, three- and octagonal.
According to the longitudinal section distinguish:
• Conical.
• Stepped with upset ends.
This is not the whole list of pipes that differ in longitudinal section. In a separate group are bimetallic, trimetallic, consisting of several layers of metal that are interconnected by welding, landing or alloying.
Seamless pipe application
Based on the destination issued for:
• oil and gas industry;
• construction;
• pipelines;
• mechanical engineering;
• vessels and cylinders.
Pipes for the oil and gas industry are made of carbon and alloy steel grades. Drill pipes are used for drilling exploratory and operational wells. Casing pipes are used to protect the walls of gas and oil wells from corrosion, liquid ingress into them, and separation of gas and oil-bearing strata from each other. Pipes for pipelines are used to deliver gas, oil, gasoline, water, acids. Tubing is used in the operation of drilling wells when oil production occurs, and have threaded connections. Boiler tubes are used in boilers of various designs. The main pipe is manufactured in accordance with GOST 3262-75 and is welded. Construction pipes in accordance with GOST 800-78, 8642-68 are used in the manufacture of various machine parts in aviation, mechanical engineering, automotive tractor construction. Cracking pipes, in accordance with GOST 550-75, are made of steel 10, 20, K5M, K5, 12MX and others and are used for pumping oil products under high pressure.
Trunk pipe
The main feature of the pipes of this assortment is the large diameter, as they are used for mounting various structures in construction, for transporting oil, gasoline, steam, oils, gas, water.
Steel main pipes are made straight-seam and spiral-seam, with a diameter of 529-2560 mm and a wall thickness of 8-25 mm. Pipes for main gas pipelines are made for operation in aggressive environments, at high pressure and in difficult climatic conditions. Thus, the location of the main regions of oil and gas production in the North of Russia necessitates the construction of powerful trunk pipelines located underground.
Difficult climatic conditions impose ultra-high demands on the quality of the pipes and their operational properties - strength and plastic characteristics. Sometimes the gas main pipe has a special coating: composite, zinc, bitumen.
The National Association of Corrosion Engineers (NACE) has created a standard that governs tests and recommendations on materials that are resistant to wet hydrogen sulfide environments. Criteria for evaluating the suitability of the material: time to failure and threshold voltage.
For pipe material used in difficult climatic conditions, it is important to reduce the temperature at which brittleness of the metal occurs, increase its viscous properties, which are determined on samples with a round notch at a minimum temperature of -60 ° C and on samples with a sharp notch at the lowest possible operating temperature -20 ° . That is why the use of main pipes made in accordance with GOST or TU is so important.
Main pipe: GOST and characteristics
Distinguish main pipes by:
1. Welding method:
• Contact welding.
• Electric arc welding.
2. Type of weld:
• Spiral seam.
• Straight-seam.
3. Purpose:
• Pipes for trunk pipelines.
• Pipes for gas pipelines.
• Pipes for pipelines with other media.
4. Diameter:
• Large diameter pipes.
• Pipes of small diameter.
It is important to remember that electric arc welding is a universal method, and the contact type of welding is used only for a main pipe with a small diameter. A large-diameter gas main pipe can be trimmed, with burrs removed. In the event that the pipe is not trimmed, the burrs are not removed at the factory.
GOST 20295-85 is the main regulatory document relating to trunk pipes.
Main pipe: assortment
A steel strip is used as a billet for the production of the main steel pipe, the material for which is high-alloy carbon (quiet, semi-quiet) steel and low-alloy hot-rolled steel.
Steel grades that are used for the production of trunk pipes:
Electric-welded main pipe in accordance with GOST 20295-85, TU 14-3-1573-96:
Assortment |
Diameter mm | steel grade |
159 | 20 |
219 | 20 |
273 | 20 |
325 | 20 |
377 | 20 |
426 | 20 |
530 | 17G1S |
630 | 17G1S |
720 | 17G1S |
820 | 17G1S |
920 | 17G1S |
1020 | 17G1S |
1220 | 17G1S |
1420 | 17G1S |
1620 | 17G1S |
1820 | 17G1S |
As you can see, the main pipe is used in difficult geological and climatic conditions, aggressive environments and is manufactured in accordance with GOST and TU, and a large assortment only strengthened the position of the main pipe among other metal products.