Home > Knowledge > Content

Marine seamless pipe under sea water

Jun 06, 2017

The steel pipe is very common in marine engineering. Two systems of ship and marine engineering demand roughly in three types of steel pipe: steel pipe in the conventional system, constructed with steel pipes and special purpose steel pipes.

steel pipe in the conventional system.
Different ship and marine engineering, both conventional systems have a dedicated system.
Ship service life of 20 years. Many of the conventional system, bilge water, ballast, dewater sewage, air, measurement, injection, domestic water, fire, cargo oil stripping, breathable, inert gas, heating, washing, foam extinguishing sprinkler, vapor, liquid level telemetry, valve remote control systems, special ships also include a dedicated system for the transportation of liquefied petroleum gas (LPG), liquefied natural gas (LNG). Marine engineering service life of up to 30 years, or even longer. Marine engineering in addition to the conventional system, special drilling equipment systems, crude oil / LPG / LNG processing workflow system, special mooring system, flare system, and so on. It has been statistics, ship pipe annual consumption of 450 million tons, about 440,000, its standards are GB, YB, CB, 70% of the steel pipe connection. Only a 30-ton very large crude oil pipes for the amount of up to tens of kilometers, only steel pipe usage (including), there are about 1,500 tons, of course, the amount of 40,000 tons relative to the hull structure or limited. In addition, taking into account the same ship, to the construction of ships, as well as many other ships, so the cumulative dosage is also a lot of. And a 300,000 tons-class number of large FPSO pipe over 30,000, more than 90 km in length, which is the same tonnage level 2 to 3 times. Therefore, the shipbuilding industry has become a big user of steel pipe market.

Steel pipe in construct
Steel tube marine engineering applications, in addition to the above conventional system with a dedicated system, many constructed a large number of steel pipes, such as jacket, underwater steel piles, Casing, mooring bracket, helicopter platform, torch tower. Type of steel pipe, material specifications, with the same diameter, reducers, different wall thickness, as well as a large number of Y, K, T-managed nodes. Such as jacket, steel piles, wellhead impermeable sleeve, mostly large diameter steel pipe sizes, are generally made of rolled steel. Their material for E36-Z35, D36-Z35, E36, D36. Such steel pipe standards have not with YB, CB, and mainly is GB712-2000. The production of steel pipe structure steel pipe manufacturing practice SY/T10002-2000 developed by China's Petroleum Industry Standards and Technology Commission (CPSC). Since China does not have the specialized enterprises, are usually the purchase of steel plate from construction units, self-molding process.

Steel pipe for special purpose
Special purpose steel special steel pipe used in the specific working environment and the working medium. Undersea pipeline is typical specialty steel pipe, the demand for larger, high strength, small tolerances, good corrosion resistance. Currently, the pipeline production is only in its infancy, because the welding materials, corrosion resistance or less Specifications (diameter and wall thickness), expensive, etc.. China's offshore crude oil need insulation transport. The past, using the double pipe insulation structure, safe and reliable. But as a protective pipe steel pipe is very economical, and offshore pipe laying ago, have to carry out internal and external pipe welding, greatly reducing the efficiency of the pipe laying, to cause installation costs increase exponentially. Into the 21st century, it has launched a concrete counterweight steel pipe. Its structure is (from inside to outside): anti-corrosion layer of steel, epoxy powder (FBE), polyurethane insulation, polyethylene (PE) jacket tube, reinforced concrete counterweight layer (the internal configuration of the steel mesh). This type of special steel, China has imported from abroad, such as the Bohai Penglai 19-3 oil field, a project using Malaysian BREDEROPRICE company products. China after research and testing, and in 2002 built in Tanggu, China's first concrete with heavy steel pipe production line, has thousands of kilometers of pipelines for offshore oilfield products. It is reported that, using this steel per kilometer subsea pipeline to reduce the cost of 50 million to 100 million, and greatly reduce the cost of offshore oilfield development, so that a number of marginal oil fields to be cost-effective to develop.