The Process of Cured-in-Place Pipe (CIPP) Installation: A Step-by-Step Guide

May 23

Cured-in-Place Pipe (CIPP) is a trenchless technology that allows for the rehabilitation of existing pipes without the need for extensive excavation. It is widely used to repair and restore the integrity of water, sewer, and other underground utility pipes that have been damaged due to age, corrosion, or other factors. The CIPP process involves creating a new, durable pipe inside the existing one, extending the lifespan of the pipe without the need for costly and disruptive digging.

In this article, we will walk you through the process of CIPP installation, from the initial inspection to the final curing stage. Understanding this process can help you see why CIPP is a preferred method for pipe repair and why it offers significant benefits over traditional methods.

See how CIPP fits into the broader scope of trenchless technology.

1. Initial Inspection and Assessment

Before any repair work begins, a thorough assessment of the existing pipe is conducted to determine its condition and suitability for CIPP lining. This step is essential to ensure that the pipe is suitable for rehabilitation and to plan the necessary repairs.

How it works:

A camera is inserted into the pipe through small access points (usually manholes) to inspect the interior.
The camera provides real-time footage of the pipe's condition, helping technicians identify cracks, leaks, corrosion, and other damages.
If necessary, cleaning of the pipe is done to remove debris, roots, or other blockages that might interfere with the lining process.

Benefits:

Identifies the exact location and severity of the damage.
Helps determine whether CIPP is the best option for repair.
Allows technicians to map out the pipe’s layout for efficient work.

CIPP's no-dig approach delivers all the key benefits of trenchless repair!

2. Cleaning and Preparation

The next step is to clean the interior of the pipe to remove any debris, grease, or roots that could affect the installation of the CIPP liner. The surface preparation is crucial to ensure proper adhesion and a smooth curing process.

How it works:

High-pressure water jets or mechanical cleaning tools are used to remove any dirt, debris, or obstructions inside the pipe.
If necessary, a root-cutting tool is used to eliminate tree roots that may have infiltrated the pipe.
The cleaned pipe is then inspected again to ensure it is ready for lining.

Benefits:

Ensures a clean and smooth surface for the liner to adhere to.
Removes blockages and obstacles that could interfere with the curing process.
Prevents future issues that could arise from debris or roots inside the pipe.

3. Measuring and Cutting the Liner

Once the pipe is cleaned, the next step is to prepare the CIPP liner. The liner is a flexible tube made of a felt or fiberglass material that is coated with a resin. The resin is what will harden and form the new pipe inside the old one.

How it works:

The liner is measured to ensure it fits the dimensions of the damaged pipe. It should cover the entire length and diameter of the pipe that needs rehabilitation.
The liner is then cut to the appropriate size and is pre-saturated with resin. The resin is a key component that, once cured, will form a strong, durable lining.
The resin-saturated liner is then carefully rolled up for insertion into the pipe.

Benefits:

The liner is custom-fitted to the damaged pipe, ensuring a precise repair.
The resin ensures the new pipe has the necessary strength and durability to last for decades.

4. Liner Insertion

Once the liner is prepared, the next step is to insert it into the existing pipe. This is done using a method that allows the liner to be inserted through a small access point and pushed through the entire length of the pipe.

How it works:

The resin-saturated liner is pulled into the existing pipe using air pressure, water, or a winch.
The liner is inverted inside the pipe, and as it moves through the damaged pipe, it gradually expands to fit snugly against the pipe’s walls.
The liner is inflated to ensure it makes full contact with the interior of the pipe.

Benefits:

The liner is securely inserted and tightly fits the shape of the pipe, ensuring a perfect seal.
This step is done with minimal disruption to the surface above, as only small access points are needed.

5. Curing the Liner

The most critical stage of the CIPP process is curing the resin inside the liner to harden it into a durable, rigid pipe. There are different methods for curing the liner, depending on the materials used and the available equipment.

How it works:

Hot Water Curing: The pipe is filled with hot water, which circulates through the liner to cure the resin. The temperature and time needed for curing depend on the type of resin and the pipe size.
Steam Curing: Steam is injected into the liner to cure the resin. Steam curing is faster than hot water curing, and it’s commonly used for large-diameter pipes.
UV Light Curing: In some cases, ultraviolet (UV) light is used to cure the resin. This method is faster and more efficient for smaller pipes.

Benefits:

The resin hardens to form a strong, durable new pipe inside the old one.
The cured liner is resistant to corrosion, root intrusion, and other common pipe problems.
The new pipe can last for 50 years or more, reducing the need for frequent repairs or replacements.

6. Final Inspection and Testing

After the curing process is complete, the new CIPP liner is inspected to ensure it meets the required standards. The pipe is tested to confirm that it is functioning properly and free from leaks.

How it works:

A final camera inspection is done to check the integrity of the liner and ensure that it has fully cured and adhered to the pipe.
Any remaining access points are sealed, and the pipe is flushed to remove any debris or residues from the curing process.

Benefits:

Ensures the quality and functionality of the repair.
Verifies that the liner is securely in place and will perform as expected for many years.
Guarantees that the newly lined pipe meets all safety and regulatory standards.

7. Restoration and Completion

Once the inspection and testing are complete, the final step is to restore the access points and the surrounding area. Since CIPP is a trenchless method, the restoration process is typically quick and minimal.

How it works:

The small access points, such as manholes, are sealed and restored to their original condition.
If necessary, the surface area above the pipe (such as roads or landscaping) is returned to its original state, but since minimal excavation is required, the restoration is generally faster and less costly than traditional methods.

Benefits:

Minimal disruption to the surrounding area, with no need for large-scale excavation or roadwork.
A completed, durable pipe that is ready to be put back into service immediately.

Conclusion

The Cured-in-Place Pipe (CIPP) method is a highly effective, efficient, and minimally disruptive solution for repairing damaged underground pipes. The process involves several key steps: inspection, cleaning, preparation, liner insertion, curing, and final testing. Each step is crucial for ensuring that the new liner adheres properly and creates a durable, long-lasting pipe inside the old one.

CIPP installation is a preferred method for pipe rehabilitation in urban environments and other areas where traditional digging would cause significant disruption. The benefits of CIPP, including its cost-effectiveness, speed, and minimal surface disruption, make it an excellent choice for extending the lifespan of existing pipes and maintaining essential infrastructure.

Frequently Asked Questions

What is Cured-in-Place Pipe (CIPP) lining?
CIPP lining is a trenchless method used to repair existing pipes by inserting a resin-saturated liner into the damaged pipe. The liner is then cured to form a strong, durable new pipe inside the old one.
How long does the CIPP process take?
The CIPP process can typically be completed within a few days, depending on the size and complexity of the project. This is much faster than traditional pipe replacement methods, which can take weeks.
What types of pipes can be repaired with CIPP?
CIPP can be used to repair a wide range of pipe materials, including clay, concrete, PVC, and cast iron. It is commonly used for sewer lines, water pipes, and other utilities.
How long does a CIPP liner last?
CIPP liners are designed to last for 50 years or more, making them a long-term solution for repairing damaged pipes.
Is CIPP more cost-effective than traditional pipe replacement?
Yes, CIPP is generally more cost-effective than traditional pipe replacement because it requires less labor, no excavation, and minimal restoration work. The reduced disruption to businesses and residents also helps save money.