The coated pipe is a group of metal pipes with anti-corrosion coatings. These coatings are commonly utilized to preserve the steel pipe used in the building of pipelines, reinforcing steel, and a broad variety of piping connections. This protective coating helps prevent corrosion, which can cause leaks, disruptions in operation, and even explosions of the steel wall.
Pipeline coating is a cost-effective and practical option for preserving the integrity of pipelines. It is widely regarded as one of the most dependable corrosion prevention technologies utilized by businesses worldwide today. However, pipeline coating is not an easy operation; it necessitates a lengthy process to complete a successful pipe painting mission.
Oil and gas coated pipes can be classified into two types, each with its own set of unique and stringent requirements: internal coated pipes and external coated pipes.
Executive Standard of Coated pipes
- API RP 5L2
- ISO 15741
- AWWA C210
- SY/T 6717
- DEP 22.214.171.124
Internal coated Pipe
Internal coating for pipelines is a process in which steel pipes are coated from the inside with a protective layer. This is done to resist the pipe to fluid or gas flow, as well as to reduce friction and wear. The most common method of internal coating is spray painting, in which a thin layer of paint is applied to the inner wall of the pipe. This type of coating provides excellent resistance to most chemicals and is very durable. Another popular option is the epoxy coating, which is often used in food-grade applications. This type of coating can provide protection against corrosion and abrasion, and it is also FDA-approved. Internal coating is an important process that helps to prolong the life of steel pipelines.
TYPES OF Internal coated pipes
Steel pipe is used for a variety of projects because it is tough and lasts a long time. One of the ways to further extend the life of steel pipe is to ensure that the interior is properly coated. There are five types of interior coating that are commonly used: coal tar enamel, cement mortar, liquid-applied epoxy, fusion bonded epoxy (FBE), and polyurethane (PU). Each type of coating has its own advantages and disadvantages, so it is important to select the right one for the project at hand. For example, coal tar enamel is durable but can be difficult to apply, while liquid-applied epoxy dries quickly but may not be as resistant to Wear and tear. Ultimately, the best way to choose an interior coating is to consult with a professional who has experience with similar projects.
- Coal Tar Enamel
Coal Tar Enamel (CTE) is a coating that is applied to the interior of steel pipes. CTE provides an extremely smooth and durable finish that is resistant to both corrosion and abrasion. The CTE process involves heating the steel pipe to over 1300°F and then coating it with a layer of coal tar. Once the coal tar has cooled, it forms a hard, impermeable barrier that protects the pipe from the elements. CTE is highly flexible and can be applied to pipes of all sizes and shapes. It also has excellent strength and adhesion properties, making it an ideal choice for use in corrosive environments. CTE-coated pipes are widely used in a variety of industries, including oil and gas, chemical processing, and power generation.
- Cement Mortar
Cement mortar pipe internal coating is a protection layer that is applied to the inside of pipes. It is often used on sewer pipes and water pipes to protect them from abrasion, corrosion, and other damage. The cost of cement mortar pipe internal coating can vary depending on the type of material used and the size of the project. However, it is generally a relatively low-cost option compared to other methods of protection. When properly applied, cement mortar pipe internal coating can provide an excellent level of protection for many years. In some cases, it may even be possible to extend the life of a pipe by several decades. As such, it is an important consideration for any infrastructure project.
- Liquid Applied Epoxy
Liquid applied epoxy pipe internal coating is a chemical resistant coating that is often used in food processing plants. It is designed to resist chemical leaching and degradation, and it can also help to protect the pipe from corrosion. The coating is applied to the inside of the pipe, and it cures to form a hard, durable surface. This type of coating is typically used on pipes that carry corrosive liquids or are exposed to high temperatures. It can also be used on pipes that transport food products, as it is non-toxic and will not contaminate the food. Liquid applied epoxy pipe internal coating is an important part of keeping pipes safe and functional in a variety of environments.
- Fusion Bonded Epoxies
Fusion Bonded Epoxy (FBE) internal coating is a chemical-resistant coating that is applied to the inside of pipes. The coating helps to resist abrasion, chemical attack, and high temperatures. It is often used in applications where pipes are exposed to harsh chemicals or high temperatures. The coating can alsoextend the pipes’ life pipes by protecting them from damage.
Polyurethane internal coating, also known as urethane coating, is chemical resistant, abrasion resistant, solid material that contains no volatile organic compounds (VOC). It is applied as a thick coating to the interior surfaces of pipes and other equipment to protect them from corrosion. Polyurethane internal coating is typically applied in two or more coats, with each coat allowed to cure before the next is applied. The cured coating is hard and durable and provides an excellent barrier against chemical attack and abrasion. Polyurethane internal coating is available in a variety of colors and can be customized to meet the specific needs of your application.
External coated Pipe
External coatings on pipelines are an important part of the oil and gas industry. They provide a barrier between the metal of the pipe and the environment, protecting the pipe from corrosion and other damage. Coatings also help to resist bacteria and chemicals that can be harmful to the pipeline. In addition, they can help to regulate temperature and protect the pipe from mechanical damage. There are many different types of external coatings, each with its own benefits and drawbacks. The type of coating that is used depends on the specific needs of the pipeline. However, all coatings play an important role in protecting the pipeline from damage and ensuring its safe operation.
TYPES OF External coated Pipes
The Fusion Bonded Epoxy (FBE) coating prevents corrosion on pipe surfaces. Double or triple layers of FBE may even improve friction and abrasion resistance. In 3-layer PE/PP coating systems, FBE coating is also employed as the priming layer.
At temperatures ranging from 220 to 235°C, the electrostatic epoxy powder is sprayed onto a pipe. When the epoxy powder reaches the hot pipe surface, it melts and forms a uniform layer of epoxy coating on the pipe.
Dual-layer FBE is used for a variety of service applications, including directional drilling, anti-abrasion for road and river crossings, and oil, gas, and waterworks pipes. This coating, like single layer FBE (above), can be applied on a wide range of outer diameter (OD) sizes, from 3.5″ to 48″. In most situations, the top layer of abrasion resistance protects against erosion.
2LPE Coating is a two-layer polyethylene coating system that provides excellent protection for steel pipelines from corrosion, chemical attack, and abrasion. The first layer is a high-density polyethylene (HDPE) liner that is applied to the steel surface. The second layer is a co-polymer adhesive that bonds the HDPE liner to the steel surface. This two-layer system provides outstanding resistance to a wide range of chemicals and temperatures. 2LPE Coating is an ideal solution for protecting steel pipelines in a wide range of environments.
2LPP Coating is a steel pipeline coating that consists of a two-layer system. The first layer is a fusion-bonded epoxy (FBE) which provides corrosion and chemical resistance. The second layer is a polyethylene copolymer that provides mechanical protection and resistance to abrasion and cathodic disbondment. This type of coating is often used in high temperature environments, as it can withstand temperatures up to 120 degrees Celsius. 2LPP Coating is an effective way to protect steel pipelines from corrosion, chemical attack, and abrasion.
The three-layer polyethylene coating system offers superior protection against corrosion compared to traditional epoxy powder and two-layer PE coatings. The FBE layer provides an effective barrier against corrosion, while the PE layer resists water penetration and mechanical damage. This coating system can withstand temperatures of up to 50°C (low and medium density polyethylene) or 70°C (high-density polyethylene), making it an ideal choice for a wide range of applications.
3PP coating is a three-layer polypropylene anticorrosive coating that is primarily used as an anticorrosive pipeline layer for conveying high-temperature mediums and as an anticorrosive pipeline layer in desert areas with high surface temperatures and long periods of sunshine. The 3PP coating consists of a base layer of epoxy powder, an intermediate layer of binder, and an outer layer of polypropylene (PP) jacket. The 3PP coating takes all of the benefits of the 3PE coating and improves its operating temperature performance significantly. The improved operating temperature performance of the 3PP coating makes it an excellent choice for use in high-temperature environments and desert conditions.