With the development of technology, lined and clad materials are more and more popular in processing industry.By combining the two materials, we can gain the advantage of the two materials at a lower cost.For onshore and offshore pipelines that require a balance between the mechanical properties of carbon steel pipes and the corrosion resistance of corrosion resistant alloys (CRA),cladding and lined pipes are available.

The clad and lined pipes are composed of carbon steel pipes which have a layer of CRA in contact with the production fluid, therefore, its corrosive environment.For clad pipes, the corrosion resistant alloy (CRA) layer uses a different procedure to create the metallurgical bond, while the lined pipe is applied through a mechanical bond between the CRA and the carbon steel pipe.

Lined Pipe

There is a mechanical bond between the lining pipe and the pipe material.

The corrosion resistance of the liner material and the strength benefit of carbon steel can be obtained by using the liner material in carbon steel pipe.

Commonly used lined material are

• PTFE
• Rubber
• Glass
• FRP (Fiber reinforced plastic)

Plastic lined flanged steel pipes

Advantages of Lined Pipe

• The lined pipe can withstand the harsh chemical environment
• And provides an abrasion resistance with a hard lining material
• This is a cost-effective solution for non-critical services

Disadvantages of Lined Pipe

• The lining pipe has the limitation of non-metallic material, for example, it cannot be used in high temperature and pressure environment
• Lining pipes are made from small length pipe spools, so there are no flanged joints on the production line, which increases maintenance costs and chances of leakages

Clad Pipe

The clad pipe has metallurgical bonding between the pipe and cladding material

• Cladding is accomplished by an explosive bonding process or by welding the clad material over the pipe
• High strength carbon steel materials are cladded with high corrosion resistant metal to achieve cost effectiveness

Weld Cladding Process

Advantages of Clad Pipe

• Clad carbon steel can withstand tough chemical environments.
• A clad pipe can be used in high temperature and pressure services
• It is cost effective for critical services as carbon steel can be used with a cladding of exotic materials.

Disadvantages of Clad pipe

• Fabrication of clad material is difficult,and welding requires a special skill
• Clad pipes are more expensive than lined pipe