Because the pipeline transportation is particularly suitable for transporting oil, gas, therefore, the pipeline in petroleum and petrochemical industry was widely used. Former petrifaction Corporation annual crude oil 120000000 T, most used by pipeline; annual production of steam, coal, diesel 5000 million tons, of which 80% with pipeline transport; petrochemical enterprise device, device of liquid or gaseous chemical materials transportation is mainly through the pipeline to complete. Therefore, petrochemical enterprises annual capital construction and in production and repair all need to use a large number of steel pipe. But, because of the petrochemical industry work is characterized by high temperature and high pressure, flammable and explosive, so for the use of steel tubes require very strict.

Straight resistance welding steel pipe development

In recent years, there is an international high-quality seamless steel pipe to replace the high cost development trend, mainly due to the welded pipe production technology constantly breakthrough, manifested in the following aspects:

( 1) desulfurization technology, so that the sulphur content of steel is reduced, improves the welding quality of steel pipe.

( 2) vacuum degassing technology, improve tube blank steel purity, reduces the inclusions, the weld seam quality improve.

( 3) because of the addition of V, Ti, Nb and other special elements, reduces the carbon equivalent, steel toughness, strength and other properties are improved.

( 4) the development of strip steel hot rolling technology, increased dimensional accuracy, so the pipe size deviation reduction.

( 5) the improvement of quality inspection methods, such as ultrasonic nondestructive testing, hydrostatic testing machine and other equipment should be used, to ensure the quality of the final product.

Straight resistance welding steel pipe used in petrochemical enterprise

Petrochemical enterprises selection of steel pipe due to bear a certain pressure, generally used in fluid with seamless steel pipe. Electric resistance welded pipe and fluid with seamless steel pipe contrast, has obvious economic benefits, mainly displays in: less investment; mechanization, automation degree is high; low production energy consumption (room temperature forming, and seamless steel pipe for heating or cold drawing molding ); the production cost is low, for seamless steel tube is about 2\/3; continuous production, productivity high yield and high. Longitudinal welded pipe industry in China started in the 50′s, started late, the production process and technology and developed country is compared, put in very big difference. The vast majority of enterprise technology equipment failure, lack of necessary means of detection, but also to the poor quality of the short belt, narrow as raw material, caused welded pipe products with small aperture, low bearing capacity, product structure is unreasonable, welded pipe production in 80% can only be used as a low pressure fluid conveying coal water pipe, all kinds of special pipe low proportion. This kind of low welding equipment and technology level, making the