Application of Steel Pipe in Ocean Engineering and Shipbuilding Industry

The shipbuilding industry occupies an important position in the development of the national economy. Research shows that among 116 industries, shipbuilding products involve 97 industries, accounting for 87%. Such as metallurgy, materials, machinery, microelectronics, electrical, hardware, textile, chemical, decoration, etc., have stimulated the development of thousands of enterprises. According to relevant data, for every deadweight ton built in the shipbuilding industry, 3000 upstream labor positions can be solved. The shipbuilding industry condenses people's wisdom and hard work, is a symbol of the country's comprehensive national strength, and it also measures a country's status in the world's shipbuilding industry and ocean engineering.

Application of steel pipes in ocean engineering:
The application of steel pipes in ocean engineering is very common. There are roughly three types of steel pipes in the two major systems of shipbuilding and ocean engineering: conventional steel pipes, structural steel pipes and special-purpose steel pipes.

1. Conventional steel pipe
Different ships and marine engineering have both conventional systems and dedicated systems.

The service life of a ship is generally 20 years. There are many conventional systems, mainly including bilge water, ballast, drainage, injection, domestic water, fire fighting, domestic sewage, air, measurement, cargo oil, stripping, ventilation, inert gas, heating, washing, foam fire extinguishing, Water sprinkling, vaporization, liquid level remote sensing, valve remote control and other systems. Special ships also include special systems for transporting liquefied petroleum gas (LPG) and liquefied natural gas (LNG). The service life of steel pipes in marine engineering is at least 40 years. In addition to conventional systems in offshore engineering, there are also special drilling equipment systems, crude oil, liquefied petroleum gas, and liquefied natural gas processing process systems.

According to statistics, it is found that the annual consumption of marine pipes reaches 5 million tons, about 500,000 pipes. The standards are GB, YB, CB, and 70% of the pipes are connected between them. The amount of steel pipes and fittings for a 300,000-ton ultra-large oil tanker can reach dozens of kilometers, and the amount of steel pipes (including) 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. of. In addition, considering the same type of ship, multiple ships must be built, as well as many other ships. The number of 300,000-ton super large FPSO pipes exceeds 40,000, and the length exceeds 100 kilometers, which is 3-4 times that of the same tonnage. Therefore, the shipbuilding industry has become a large user of the steel pipe industry.

2. Steel pipes for structural purposes
In the application of steel pipes in marine engineering, in addition to the above-mentioned conventional systems and special systems, many structures use a large number of steel pipes, such as jackets, risers, underwater steel piles, helicopter platforms, mooring brackets, and torch towers. This kind of steel pipe has many specifications and high materials, with the same diameter, different wall thickness, different diameter, and a large number of Y, K, T-shaped pipe joints. Their materials are E36-Z35, D36-Z35, E36, D36. The standard of this kind of steel pipe is not YB, CB, but mainly GB712-2000. The production of steel pipes is in accordance with the "Structural Steel Pipe Manufacturing Code" SY/T10002-2000 formulated by the my country Petroleum Industry Standards and Technical Committee (CPSC). Since there is no specialized enterprise in our country, the steel plate is usually processed and formed by the construction unit after purchasing it.

3. Special purpose steel pipe
Special-purpose steel pipes refer to steel pipes used in specific working environments and working media.

Among them, the submarine oil pipeline is a typical special steel pipe, which is in large demand, has the characteristics of high strength, good corrosion resistance, and small tolerances. At present, the production of submarine pipelines in my country is still in its infancy because of corrosion resistance, few welding materials or specifications, and high prices.

Crude oil on the sea needs to be transported with insulation. In the past, the double-layer steel pipe insulation structure was used, which was safe and reliable. However, it is not economical to use steel pipes as protective pipes. Before offshore pipe laying operations, the inner and outer pipes must be welded, which greatly reduces the pipe laying efficiency and doubles the installation cost. increase. After entering the 21st century, people introduced a concrete counterweight steel pipe. Its structure is (from inside to outside): steel pipe, epoxy powder (FBE) anti-corrosion layer, polyethylene (PE) jacket pipe, polyurethane insulation layer, reinforced concrete counterweight layer (with steel wire mesh inside). This type of special steel pipes were imported from abroad by China. For example, the first phase of the Penglai 19-3 oilfield project in Bohai Sea uses the products of the Malaysian Bredero Pric company.

After research and testing, the first domestic concrete counterweight steel pipe production line was built in Tanggu in 2002, which has provided thousands of kilometers of pipeline products for many offshore oil fields. It is reported that the use of this kind of steel pipe can reduce the cost of 500,000 to 1 million yuan per kilometer of submarine pipelines, greatly reducing the development cost of offshore oil fields, and enabling a number of marginal oil fields to be developed economically and effectively.

Tips: ERW welded pipe is formed by rolling strip and welding the seam, with tighter dimensional tolerances and less weight. The weld seam is heat treated after welding that no untempered martensite remains, and the weld flash can be removed from both inner and outer surfaces.  

ASTM A53 Grade B Seamless is our most popular product under this specification and A53 pipe is commonly dual certified to A106 B Seamless pipe.