The Difference Between One-Piece and Split Steel Casing Pipe

Steel casing pipe is a type of pipe material, typically made from seamless steel pipe and generally conforming to the API SPEC 5CT international standard. It offers excellent high-temperature and pressure resistance and is widely used in the petroleum, chemical, geological, metallurgical, and construction industries. One-piece and split casing pipe are two common types of casing pipe, with significant differences in design, installation, use, and maintenance.

What is One-Piece Steel Casing Pipe?

One-piece steel casing pipe is manufactured from a single piece of steel, without any joints or segments. It features strong integrity and excellent sealing properties, and is often used in projects requiring high safety, waterproofing, and fire resistance.

What is Split Steel Casing Pipe?

Split steel casing pipe is made from two or more sections of steel, joined together by welding or bolting. It is often used for pipeline repair and reinforcement by cutting the steel pipe in half horizontally and then reconnecting it by welding or bolting. Features include easy connection and installation, and customizable lengths and diameters.

Main Differences Between One-Piece and Split Steel Casing Pipes

1. Design Differences

Structure of One-Piece Steel Casing Pipes

Its design features a monolithic structure, meaning all casing pipe components are pre-assembled to form a complete unit. This design makes the casing pipe more stable and capable of withstanding greater pressure and loads.

Structure of Split Steel Casing Pipes

Its design is relatively flexible, consisting of multiple components. This design facilitates customization and installation based on specific needs, as well as partial replacement in the event of damage.

2. Differences in Strength and Sealing Performance

Performance of One-Piece Steel Casing Pipes

High strength, good integrity, and uniform load distribution. Since there are no joints, the casing pipe offers superior sealing, impermeability, and corrosion resistance. It is suitable for high-pressure or high-intensity applications.

Performance of Split Steel Casing Pipes

Joints can become weak links, making them more susceptible to leakage or loosening over time. Sealing relies on welding or sealing rings, making it slightly less reliable than one-piece casing pipes.

3. Differences in Usage and Maintenance

Usage and Maintenance of One-Piece Steel Casing Pipe

Due to its stable structure, the failure rate during use is relatively low, and maintenance requirements are minimal. However, when repairs are needed, the entire unit may need to be replaced, which is costly.

Usage and Maintenance of Split Steel Casing Pipe

Although its structure is relatively complex, if a part is damaged, only the damaged part can be replaced, reducing repair costs. Furthermore, its flexible design makes it easier to adapt and upgrade.

4. Comparison of Installation Methods

Installation of One-Piece Steel Casing Pipe

Due to its integrated design, the installation process is relatively simple. Simply place the entire casing pipe unit in the designated location and secure it. This installation method saves time and reduces potential installation errors.

Installation of Split Steel Casing Pipe

The installation process is relatively complex, requiring each unit to be installed separately before assembly. While this increases the number of installation steps, it also provides greater flexibility and adaptability to a wider range of installation environments.

5. Differences in Application Scenarios

Applications of One-Piece Steel Casing Pipe

Its application is primarily used in new construction projects, particularly where high strength, waterproofing, fire resistance, and corrosion resistance are required.

For example: underground pipe corridors, fire protection pipe wall penetrations, nuclear power plants, petrochemical plants, and other critical facilities.

Applications of Split Steel Casing Pipe

It is primarily used in renovation projects or construction environments with limited space, suitable for situations where a full-length casing pipe is not feasible.

For example: pipeline reinforcement in older buildings, local repairs, and reinforcement during pipe replacement.

6. Cost Differences

The Cost of One-Piece Steel Casing Pipe

The manufacturing process requires a high level of precision and is relatively high in cost.

The Cost of Split Steel Casing Pipe

The process is more flexible, with lower processing and transportation costs, but ongoing maintenance costs may be higher.

How to Choose the Right Steel Casing pipe?

1. For new construction, one-piece steel casing pipe is recommended because it offers greater strength and sealing, ensuring long-term stable system operation.

2. For renovations of older pipelines or in space-constrained environments, split steel casing pipe is more convenient to install and offers more flexible processing.

Summary

In general, one-piece and split steel casing pipe each have their advantages and applicable scenarios. The integrated casing pipe offers a stable design and easy installation, making it suitable for applications requiring high stability. The split casing pipe, on the other hand, is more suitable for complex and changing environments due to its flexibility and ease of maintenance. When choosing between the two, consider the trade-offs based on your specific needs and conditions.