The biggest difference is that pipe lining is only covered from the inside, and pipe coating can be covered from the inside or outside. Thus, pipe lining is mostly used for reparations, and pipe coating is used to add a corrosion-resistant cover.
What Is Pipe Lining?
Pipelining or Pipe relining is a method applied to repair a pipe from the inside by using resin to fill up the damages. Relining a pipe is cheaper than digging a trench and replace the entire pipe. Thus, pipe relining is a faster solution that can add more durability to the pipe. However, according to the damage, pipe relining is not always the best solution.
Though, relining a pipe has more benefits than cons. First of all, pipe relining is fast a solution that it can be done easily. Also, it is an accessible option for everyone that is low-cost. Another pro for pipe relining is that any other surface is damaged; to repair a pipe using the relining method, it is not necessary digging up drains, drilling holes, nor open trenches.
Pipe relining is also a safer option for everyone. The risk is minimal since it doesn’t involve any difficult job, or create a vulnerable spot on the surface that can provoke an accident. Thus, it is a more durable option, because it adds more strength to the whole structure of the pipe.
How Does Pipe Lining Work?
Pipe lining is easy than change the whole pipe; however, this is a process of attention that requires precision and dedication. A wrong application of this relining method can get worse the damages or obstruct the whole pipe. Thus, non-experts eyes may think that pipe lining is a long and complex process than “simply change the pipe for a newer one,” but it is indeed simpler and cheaper to reline a pipe; additionally, pipe lining can add extra strength to the pipe.
Pipe lining also receives the name of Cured-In-Place Pipe. However, the process can be divided into two parts with several steps. Here is a summary of how this process is done:
Installation
A liner is lining and inserting into the damaged pipe. This liner receives the name of liner, and it is cover with a special resin that will fill the damages over the pipe. But before that, the damaged pipes have to be clean by removing the obstructions and using water pressure. An expert also checks the pipe before and after the cleaning, so it can evaluate the damages and determine if the pipe is ready to be relined. Then, the pipe is finally measured to establish the length of the liner that goes inside the pipe.
Curing
Once it is determined the length of the liner, this is impregnated with epoxy resin. This liner is made of polyester, fiberglass, or a material resistant that can be saturated with resin and overcome successfully the curing process. The liner is inserted on the pipe using air pressure (though, some use hot water pressure that accelerates the curing process.) Consequently, the curing process starts; here, UV radiation is used to cure the resin; this is indeed the longest step, but steam or hot water can be used to accelerate it.
Which Materials Are Used in Pipe Lining?
The tube that goes inside the pipe is commonly made of polyester, carbon fiber, or fiberglass; other materials resistant to corrosion that can also be covered with resin are used. However, the tube should go smoothly throughout the pipe, cover the damages perfectly, and resist corrosion and other agents that may deteriorate the inside of the pipe.
The liners are impregnated with epoxy resin. The epoxy resin works as an adhesive; thus, it is resistant to heat and chemicals. The epoxy resin prevents corrosion and gives a clean finish to the reparations.
Using accurate materials to reline a pipe will give more durability, cleaner, and professional finish to the pipe.
Is Pipe Lining Worth It?
Pipe relining is cheaper than replacing the whole pipe; however, this is not always the accurate solution. Take into consideration a few conditions that can delimit the pipe relining process, the final result, and the overall performance of the pipe over time.
Relining is almost impossible when the pipe diameter is less than 4 inches. The resin needs space to harden properly; also, the original diameter of the pipe will reduce after the liner is inserted into the pipe. Thus, joints are also a problem if a cured-in-place method wants to be used; in these cases, it is better to change the joint than relining the pipe.
The liner is indeed made especially for a specific pipe repair; thus, some standard-size liners are mostly used for smaller constructions. Therefore, pipe relining can take from one hour to almost two days accordingly to the size of the project.
However, it is not only about complications. Pipe relining is a process that doesn’t require any excavation, drilling, or complex treatments. Also, it is cheaper than the digging and replacement methods, and it indeed is safer to reline a pipe. Thus, pipe relining offers extra durability to the pipe, and epoxy resin is a material that resists corrosion. So, whenever it is possible to do a pipe lining, this method will bring advantages to the final result and the performance of the pipe after the repair.
What Is Pipe Coating
Pipe coating is a method used to strengthen the pipeline, and it prevents damages to the pipeline structure. Pipe coating gives extra protection to the pipe structure; though, it is a complex process that requires precision and follows every part carefully. Moreover, it provides durability to the pipeline making it more resistant to corrosion,
Pipe coating also gave extra advantages such as smooth finish, decrease energy consumption, and control of the corrosion of the pipelines.
The pipe coating process is similar to the pipe lining, and it can be divided into two parts: coating and curing. This process follows these steps:
- An expert does a first check control of the pipes and other elements of the process.
- Then, the pipes are cleaning and receive a preheating treatment
- Then, the pipes receive a second checking
- Now, here came the coating part that can be done in several ways (internal or external coatings).
- After the coating, it is time for the curing.
What Is the Difference Between Lining and Coating?
The biggest difference is that pipe lining is only covered from the inside, and pipe coating can be covered from the inside or outside. Thus, pipe lining is mostly used for reparations, and pipe coating is used to add a corrosion-resistant cover. However, each of them has its pros and cons; let’s read more about them.
Pipe Lining
Pipe lining or relining is an internal repair of damages in the pipe structure. The pipe lining is a low-cost solution that will not leave any damages to the landscape or building where the pipeline is located; because of this, pipe lining is a non-invasive process and doesn’t cause any environmental damage. However, a pipe lining reparation is not for all types of damage; whenever these damages are in a joint or the pipe diameter is smaller than 4 inches, the pipe lining is out of plan. Also, some pipes require special measures, so the liner is made especially for that reparation, resulting in higher costs.
Pipe Coating
Pipe coating is used to protect the pipe surface against the environment and external damages; thus, this can be applied to the inside of the pipe. Therefore, there are different types of coating, and each of them has its advantages and disadvantages.
Let’s talk about first the Coal Tar Enamel Coatings; this adheres easily to steel, but it is considered dangerous for humans and animals. Then, it is Metallic Spray Coatings which offer corrosion protection, are made using heat, and are low-cost. Also, it is the famous Epoxy Coating; this is very adhesive, offers corrosion protection, and is low-cost; however, the epoxy resin has low abrasion resistance. Finally, it is the Multi-layer system of Polyolefin or Epoxy; these have an overall high resistance and are very adhesion, but they are more expensive than the other coatings.
Conclusion
Pipe coating and pipe relining are useful methods to keep in optimal conditions the pipeline structure. However, it is important to determine when are necessary and which to choose.
Sources: https://www.architecturelab.net/what-is-pipe-relining-and-how-does-it-work/ https://nuflow.net/what-is-pipe-relining-and-how-does-it-work/#:~:text=Pipe%20relining%20is%20a%20way,flow%20and%20sealing%20off%20cracks.
