Fluid pipe steel grade

Fluid pipe steel grade

 

         

The trend of gradually increasing the delivery pressure of the pipeline medium, particularly evident in gas steel pipe. This is because in a certain range to improve the delivery pressure will increase the economic benefits to gas pipe, for example, under the same conditions in the transmission volume, as to improve the density of the gas delivery pressure increases and velocity decreases, so that the friction decline.

 

    Decreased pit stop to play pressure in a gas station spacing of steel pipe, and the flow rate gradually increased the attendant friction gradually increase, it is from the pit mouth 3/4 length consumed half of the station to give birth to the differential pressure △ p a length of 1/4 then consume the other half. The biggest difference is that of the gas pipe with oil steel pipe from pit to outbound velocity is gradually increased, which is caused by the compressibility of the medium. And the oil is substantially incompressible, along the tube side of the conveying pressure is gradually decreased, but the flow rate is constant, the friction before and after the same. This shows that for the improvement of gas steel pipe pressure can decline friction, and transportation energy consumption decreased.

      It should also be noted that the gas pipe energy consumption than oil, only the West-East steel pipe, for example, the steel pipe delivery pressure p: 10MPa, the transmission capacity of 12 billion m3 / year, and the length of pipe 4000KM rough Press empirical estimation of energy consumption is approximately 1.2 billion m3 / year, while the amount of traffic. 1/10 as along the energy consumed.

 

    The tendency towards increased delivery pressure to reduce energy consumption concerns. The early, Sichuan Province of natural gas pipe delivery pressure of 2.5MPa, after increased 4MPa, Shaanxi-Beijing Line upgraded to 6MPa, West-East increased to 10MPa economically developed countries abroad last ten gas gas steel pipe select 12MPa.

 

    In the gas steel pipe pressure ratio also decreased gradually. So-called pressure ratio refers to the ratio of the pressure of the the pitted pressure and outbound, pressure than the reduction means across the board are run at higher pressures, this also enables the power consumption decreases. Early pressure is more than 1.6, and later fell to 1.4 in recent years, some foreign gas steel pipe to take the pressure ratio of 1.25. Of course, the pressure ratio decreases, the number of compressor stations to increase, so that the investment will increase. Diameter, pressure, pressure ratio required to optimize the calculation, comparison and selection.

 

    Determine when the transmission capacity, determined by optimizing the diameter, pressure, pressure ratio, such as selecting a higher pressure steel strength grade is too low, it will cause excessive wall thickness, pipe, site welding and transportation links with to be difficult, and even harder to achieve. Production needs to promote the improvement of the steel grade.

 

      API APl5L standard released in 1926, initially include three steel grade A25, A, B, minimum yield values of 172, 207, 251MPa. API APl5LX standard released in 1947, the increase in the standard X42, X46, X52, three steel grade minimum yield values were 289, 317, 358MPa. 1966, has released the X56, X60, X65 of X70 four steel grade, the minimum yield values were 386, 413, 448, 482MPa. 1972 API release U80, U100 standard minimum yield values were 551, 691Mpa after API in turn U80, U100 changed to X80, X100. Rough statistics, the world before 2000 X70 amount of about 40%, X65, X60 are hovering around 30%, a considerable number of optional X52 steel grade refined oil pipe of small caliber, mostly ERW steel pipe.

 

    X80 steel grade, domestic, outside talk a lot, told X80 developed consumed huge amounts of investment in the international steel giant is more positive publicity of X80, or X100, but today X80 only at the stage of "test section, the total length of only about 400KM. currently no construction steel pipe grade X80, planned or being prepared in the construction of steel pipe is no determined using X80 by this I have the technical staff of the pipeline project and a number of foreign companies (responsible for pipeline design) exchange views, everyone is basically the same view, can be summarized as follows: