Reference standards

Current national standards and regulations, mandatory standard provisions, etc;

Code for Construction and Acceptance of Building Anti corrosion Engineering (GB50212-2002)

GB8923-1988 "Standard for Corrosion and Derusting Grades of Steel Surfaces before Coating"

Safety Regulations and Safety Management Rules for Painting Operations (GB6514-1995)

Quality Requirements for Anti corrosion Coatings (GB6514-1991)

Safety Regulations for Paint Operations, Paint Process Safety, and Ventilation Purification (DJ/T6931-1999)

Code for Construction and Acceptance of Industrial Equipment and Pipeline Anti corrosion Engineering (HGJ229-91)

Safety Regulations for Painting Operations - Safety of Pre treatment Processes for Painting (GB7692-87)

Noise Limits for Construction Sites (GB12523-90)

ISO9001 Quality Management System Documents

ISO14001 Environmental Management System Document

GB/T28001 Occupational Health and Safety Management System Documents

Design basis

Environmental conditions: The corrosion level of atmospheric environment on building steel structures under long-term action can be determined according to Table 1.

Oceanic atmospheric zone

1. Corrosion environment in the marine atmospheric zone

The platform structure is entirely in the atmosphere. In atmospheric regions, corrosion is caused by moisture and oxygen in the air. The atmosphere has high humidity, long hours of sunshine, and contains salt particles and salt mist. These substances accumulate on the surface of the structure to form a good liquid film, which constitutes favorable conditions for electrochemical corrosion. The corrosion suffered is several times that of land. Especially the lower part of the deck, which has been in a humid area for a long time, is the most severely corroded area in this area.

Steel structures located in the atmospheric zone are generally coated for corrosion protection. The platform deck, wharf, pipeline support, and non insulated pipelines can all use anti-corrosion structures with primer, intermediate paint, and topcoat.

Table 1: Graphene coating technology is used for anti-corrosion of steel structures in atmospheric areas

Table 2: Hot dip galvanizing using graphene coating technology

Splash/Tide Zone

1. Corrosion environment in splash/tidal zone

The interval between dry and wet alternation of the platform under the action of tides and waves. It is the most severely corroded part in the marine environment. Due to frequent wet surfaces and contact with air, there is sufficient oxygen supply on the surface. The alternating effects of long-term wetting and short-term drying of surfaces, as well as wave erosion, impact of floating objects, and erosion by marine microorganisms, result in physical and electrochemical corrosion damage, with the greatest damage.

Steel structures in the splash zone and tidal zone are coated for corrosion protection In addition, as this area is the most difficult to implement anti-corrosion protection, it is necessary to increase the corrosion allowance.

Table 1: Cathodic protection graphene coating technology is used for steel structures in splash and tidal zones

Full immersion zone

1. Corrosion environment in the fully immersed area

The platform is located in the soil below the splash zone and above. The corrosion of steel platforms in the fully immersed zone is mainly affected by dissolved oxygen, forming electrochemical corrosion. Corrosion in shallow waters may occur more rapidly than in the ocean atmosphere, and the oxygen content in deep sea areas is often much lower than in the surface. The water temperature is close to 0 ℃, and corrosion is relatively mild.

Table 1: Graphene paint technology is used for anti-corrosion of steel structures in the fully immersed zone

Underwater mud area

1. Corrosion environment in the seabed soil area

The platform is completely inserted into the seabed soil, and there are bacteria such as sulfate and reducing bacteria present. The sources and characteristics of seabed sediments vary. The platform in this area is less affected by seawater, with low temperature and minimal corrosion, except for some corrosion at the junction of ocean currents.

Table 1: Steel structures in the fully immersed and mud areas generally use cathodic protection graphene paint technology