Requirement for marine engineering steel pipe materials

Requirement for marine engineering steel pipe material is essentially the requirement for the steel itself, there are low carbon steel, high strength steel, super high strength steel and stainless steel four categories. And in terms of the steel pipe, there are the following three aspects demand:

1. Conventional system steel pipe
For different ship and marine engineering, there are both conventional systems and proprietary systems. Ship life is generally 20 years. Conventional systems: bilge, ballast, sparse drainage, sewage, air, measuring, implantation, domestic water, fireproof, cargo, stripping, air, inert gas, heating, washing, foam fire extinguishing, watering, evaporation gas, liquid level sensing, remote control valves and other systems, special ships also include transportation of liquefied petroleum gas (LPG), liquefied natural gas (LNG) and other special systems. Marine engineering life is up to 30 years or even longer. In addition to conventional marine engineering systems, there are special drilling equipment systems, workflow systems Oil / LPG / LNG processing, special mooring system, flare systems, and so on. Therefore, the shipbuilding industry has become a big user of steel pipe market.

2. The structural steel pipe
Marine engineering steel pipe applications, in addition to the above conventional systems and proprietary systems, many construction uses a lot of steel pipes, such as jacket, underwater steel piles, watertight casing, mooring bracket, helicopter platform, torch tower and so on. Such steel pipe is with many specifications, high materials, and has the same diameter, different diameter and different wall thickness, as well as a large number of Y, K, T type of pipe nodes, such as jacket, steel piles, wellhead riser sets, mostly for large diameter steel pipe, and usually crafted with steel volumes. They are made of E36-Z35, D36-Z35, E36, D36. Standards for such steel pipe is no longer YB, CB, but mainly GB712-2000. Steel production is based on the Technical Committee of China's petroleum industry standards (CPSC) developed "structural steel manufacturing practice" SY / T10002-2000.

3. Special-purpose steel pipe
Special-purpose steel pipe means the special steel pipe under specific working environment and working media. Subsea pipeline is the typical special steel pipe, with larger demand, high strength, small tolerances, good corrosion resistance and other characteristics. At present, China's subsea pipeline production is still in its infancy because of welding materials, corrosion resistance or small size (diameter and wall thickness), expensive price and so on.
China's crude oil at sea need insulation delivery. In the past, double insulation structure pipe is safe and reliable, however, as protection tube it is not economical, and when do offshore pipe laying operations, inside and outside pipe welding shall be carried out at first, which greatly reduced pipe-laying efficiency, resulting in installation costs doubled. In the 21st century, people launched a concrete counterweight pipe. Its structure is (from inside to outside): steel, epoxy powder (FBE) coating, polyurethane insulation, polyethylene (PE) jacket pipe, reinforced concrete counterweight layer (internal configuration of steel wire). It is reported that, with this pipe, per kilometer subsea pipeline can reduce the cost of 0.5 million to 1 million yuan, greatly reducing the cost of offshore oilfield development, so that a number of marginal oil fields to be developed efficiently economically.