Thick-walled straight seam steel pipe for marine engineering

The service life of ships is generally about 20 years, and the service life of steel pipes in marine engineering can reach at least 40 years. In addition to conventional systems, there are also special drilling and production equipment systems, as well as processing flow systems for crude oil, liquefied petroleum gas and liquefied natural gas in offshore engineering.

  Through calculation, it is found that the annual consumption of large-diameter straight seam steel pipesfor marine use is 5 million tons, about 500,000 pieces, and its standards are GB, YB, CB, and 70% of the steel pipes are connected. Only a 300,000-ton super-large oil tanker can use dozens of kilometers of steel pipes and pipe fittings, and the steel pipe (including) volume is about 1,000-1,500 tons. Of course, the amount of steel pipes used in the hull structure of 40,000 tons is still relatively limited. Also, considering the same kind of ships, there are a lot of other ships to build. A 300,000-ton super-large FPSO has more than 40,000 pipes and a length of more than 100 kilometers, which is 3-4 times that of the same tonnage. Therefore, the shipbuilding industry has become a major user of the steel pipe industry.

In addition to the conventional and special systems mentioned above, thick-walled straight seam steel pipes are used in many structures, such as jackets, underwater steel piles, casings, mooring brackets, helicopter channels, flare towers, etc. This kind of thick-walled straight seam steel pipe has many specifications, high raw materials, and has the same diameter, different diameter, different wall thickness, Y-type, K-type, T-type pipe joints. Such as jackets, steel piles, wellhead water jackets, etc., mostly large-diameter thick-walled straight-seam steel pipes, generally rolled from steel plates.

  In addition to the dimensional requirements of thick-walled straight seam steel pipes, its corrosion resistance requirements are also very high. Because the steel pipe is exposed to water and various media in water for a long time, the corrosion of the steel pipe is very serious, so the thick-walled straight seam steel pipe should be treated with anti-corrosion before use.