Views:29 Author:Site Editor Publish Time: 2019-03-04 Origin:Site
Natural gas pipe is widely used in our daily life. Different kinds of gas pipe have different functions. So, what type of gas pipe is used for natural gas?
Gas pipe lines can be divided into three types according to their purposes: collection gas pipelines, gas pipelines and gas distribution pipelines.
Collection of gas pipe: from the gas field wellhead device through the gas collection station to the gas treatment plant or starting point pressure station pipeline, mainly used to collect the natural gas extracted from the strata without processing. Due to the high pressure of the gas well, the general pressure of the gas collection pipeline is about 100kg force/cm 2 or more, and the pipe diameter is 50 ~ 150mm.
Gas pipe line: from the gas treatment plant or starting point of the air source pressure gas station to distribution center, large users, or in the great cities of the gas storage of pipes, as well as the interconnection between air pipeline, transmission processed in conformity with the quality standards for gas pipe line of natural gas (see gas transmission pipeline technology), is the main part of the gas transmission system. The diameter of the gas transmission pipeline is larger than that of the gas collection pipeline and the gas distribution pipeline. The maximum diameter of the gas transmission pipeline is 1420mm. Natural gas is transported by pressure stations at the starting point and along the line, with a pressure of 70 ~ 80 kg/cm 2. The total length of the pipeline can reach several thousand kilometers.
Gas distribution pipeline: from the city pressure measuring station to the user branch pipeline, low pressure, branch, pipe network dense, small diameter, in addition to the use of a large number of steel pipes, low-pressure gas distribution pipeline can also be used plastic pipe or other materials of the pipeline.
Gas pipe lines are assembled by connecting single pipes one by one.
Modern gas collection pipe and gas transmission pipe are made of steel pipe connected by electric welding. The steel pipe has seamless pipe, spiral seam pipe, straight seam pipe, seamless pipe is suitable for pipe diameter of 529 mm below, spiral seam pipe and straight seam pipe is suitable for large diameter pipe. The pipe cross section structure of the gathering and transportation pipeline, the complex is the inner coating - the steel pipe - the outer insulation layer - the heat preservation (cold preservation) layer; Simple is only the steel pipe and the outer insulation layer, and the inner wall coating and insulation (cold) layer are subject to the process of gas transmission and then determined.
The tube is widely used x-60 low-alloy steel (strength limit 42kg force/cm 2), and began to use x-65, x-70 and other materials of higher strength. In order to reduce the friction resistance in the pipeline,426 mm above the new steel pipe has been widely used in the inner coating.
Gas in different physical properties in the same pipeline transportation, and - 70 ℃, 77 kg/cm2 at low temperature high pressure gas and liquid natural gas pipe line testing.
The natural gas pipe line transmission system is composed of two parts: gas pipe line transmission station and line system. The line system includes pipeline, valve chamber along the line, crossing building (see pipeline crossing engineering and pipeline crossing engineering), cathodic protection station (see pipeline anti-corrosion engineering), pipeline communication system, dispatching and automatic monitoring system (see pipeline monitoring), etc.
Steel pipe is the main material of pipes. Natural gas conveying steel pipe is a special metallurgical product formed by deep processing. The microstructure of gas pipe line steel is different from that of other manufacturers due to the difference of technology.
In the 1960s, X52 steel grade was generally adopted; in the 1970s, X60 and X65 steel grade were adopted; in the 1980s and 1990s, X70 steel was mainly used. X80 steel has been used in some foreign gas pipe lines. With the continuous development of pipeline steel research, Canada and other countries have laid test sections of X100 and X120 pipeline steel.
For the first time, X80 grade pipeline steel was used in the 7.71km test section of jin-ning tie line pipeline project in China. The second line of the 4843km west-east gas transmission line is all made of X80 steel pipe with a diameter of 1219mm, which increases the gas transmission pressure to 12Mpa. In general, X80 steel has ferrite and bainite biphasic structure, X100 pipe steel has bainite structure, and X120 pipe steel has ultra-low carbon bainite and martensite. For the pipes of natural gas pipe lines, strength, toughness and weldability are the three most basic quality control indexes.
One of the widely used gas pipes is the HDPE/PP Profiled Pipe. To select and purchase quality gas pipes?
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