Steel pipe is widely used in shipbuilding industry. It has three major categories in the two major systems of shipbuilding and ocean engineering: steel pipes used in conventional

systems, steel pipes for construction, and steel pipes for special purpose.

Different ships and ocean engineering both have conventional systems and special systems

General speaking, the service life of ships is approximate 20 years. Conventional systems are very large, majors are bilge water, drainage water, sewage, measurement, air, injection, the living water, fire, oil cargo, stripping, breathable, inert gas, heating, washing, foam, vapour, liquid level telemetry, valve remote controlling etc. system, special ships also include transportation of liquefied petroleum gas (LPG), liquefied natural gas (LNG) etc. special system. In addition to the conventional system， there are special drilling equipments, system processes of crude oil and liquefied petroleum gas / liquefied natural gas processing, special mooring system, flare system, and so on

In ship construction, in addition to the conventional system and special system, other constructions use a lot of steel pipes, such as jacket, underwater steel stack, casing pipe against the water, mooring support, helicopter platform. These kinds of steel pipe specifications is a lot, steel grade is high, diameters and wall thickness of pipes are different or same, also have a large number of Y, K, T type of pipe joints, such as jacket, steel piles, wellhead isolation jacket etc, these made by steel plates, the materials are E36-Z35、D36-Z35、E36、D36.

The standard of chinese steel pipe for shipbuilding is based on China's Petroleum Industry Standard Technical Committee (CPSC) to elaborate the "structural steel pipe manufacturing specifications" .