At
present, long-distance oil and gas transportation mainly uses pipelines. The
pipeline steel pipes used in long-distance pipelines mainly include SSAW and
LSAW. Since the SSAW is made of strip steel, the wall thickness is limited, and
the improvement of steel grade is limited by the heat treatment of the
material. In addition, SSAW have some difficult-to-overcome shortcomings, such
as long welds, large residual stress, and poor weld reliability. With the
increasing requirements for oil and gas transportation steel pipes, they are no
longer used in densely populated areas and areas with high reliability
requirements. LSAW are gradually replacing SSAW.
1. Recently, China is accelerating the development of oil and gas in the East China Sea. As oil production develops to the depths of the ocean, due to the influence of composite forces such as pressure, impact force and bending force on the pipelines laid on the seabed, flattening also occurs, which is the weak link of SSAW. In order to improve the pipeline transportation capacity and ensure that the submarine pipeline develops in the direction of thick walls, submarine pipelines mostly use LSAW. Therefore, compared with SSAW, LSAW have higher dimensional accuracy and are easier to repair, so from this aspect, LSAW are also the first choice.
2. Coal slurry, ore slurry and slurry pipelines need to use LSAW. Pipeline transportation is "paste-like" and pipeline transportation is in the upward direction. Since the weld excess height of LSAW is a spiral line, it has great resistance to coal slurry and the pipeline requires a larger wall thickness, so LSAW tend to be used.
3. Machinery, construction, chemical industry and other industries need LSAW. At present, the machinery industry uses forgings to manufacture valve seats and then processes the inner hole, which is labor-intensive, time-consuming and material-consuming. If thick-walled LSAW are used, it will be much more economical. In addition, due to the mechanical properties requirements of anti-flattening, only LSAW are used for construction pipes; chemical pipes also hope to use LSAW.
Our company's products are mainly used for high,
medium and low pressure fluid transportation pipelines and structural steel
pipes such as oil, natural gas, water, steam and coal gas, and have undertaken
landmark engineering construction at home and abroad. The products are sold to
various cities and exported to more than 80 regions such as Southeast Asia, the
Middle East, Europe and the United States, and enjoy a high reputation in my
country.
