Introduction

When it comes to gas pipes, selecting the right material is crucial. In this article, we will compare two commonly used piping materials: PEX-AL-PEX and PE-AL-PE. By exploring their structural and performance characteristics, installation processes, and cost-effectiveness, we aim to provide insights to guide your selection.

Insight into PEX-AL-PEX Gas Pipes

PEX-AL-PEX gas pipes, also known as multilayer or composite pipes, are an innovative type of piping that combines the benefits of metal and plastic piping. They're designed specifically to cater to the rigorous requirements of gas systems.

Here's a quick rundown of the structure of a PEX-AL-PEX gas pipe:

PEX Outer Layer: The outermost layer of the pipe is composed of cross-linked polyethylene (PEX), a type of high-density plastic material that is both flexible and corrosion-resistant, enabling it to endure various environmental conditions without being damaged.

AL Middle Layer: The middle layer is made of aluminum. This layer provides the pipe with its shape and rigidity, allowing it to withstand high pressures and temperatures, and to retain its shape after bending. Moreover, the aluminum layer acts as an oxygen barrier, preventing the gas from escaping the pipe.

PEX Inner Layer: The innermost layer, like the outer layer, is made of cross-linked polyethylene (PEX). This layer is resistant to the potential chemical impact of the gas passing through it, ensuring a clean and efficient flow of gas.

The PEX-AL-PEX pipe combines the benefits of both plastic and metal pipes. It provides the strength and temperature resistance of metal pipes and the flexibility and corrosion resistance of plastic pipes. Due to these benefits, PEX-AL-PEX pipes are widely utilized in natural gas and liquefied petroleum gas (LPG) systems.

Understanding PE-AL-PE Gas Pipes

PE-AL-PE pipe, as the name suggests, is a type of composite pipe composed of three layers. This particular type of composite pipe has been widely used for a variety of purposes, with gas pipelines being one of its main applications.

Here's a breakdown of the structure of a PE-AL-PE pipe:

PE Outer Layer: The exterior layer of the pipe is made of Polyethylene (PE), a type of plastic. This layer is designed to provide corrosion resistance and protect the interior aluminum layer from any outside elements or mechanical damage.

AL Middle Layer: The middle layer is composed of aluminum. The aluminum layer serves as the oxygen barrier and provides the pipe with its structure, rigidity and allows the pipe to maintain its shape after bending. It also provides great resistance to temperature changes and pressure, thus reducing the risk of leaks and fractures.

PE Inner Layer: The inner layer is again made of Polyethylene (PE). This PE layer is designed to resist any chemical damage from the gas passing through the pipe and provides a smooth surface for efficient gas flow.

PE-AL-PE pipes combine the advantages of both plastic and metal pipes. They offer the flexibility and corrosion resistance of plastic along with the structural rigidity and longevity of metal. This makes it suitable for a wide array of applications, including natural gas and liquefied petroleum gas (LPG) systems.

Comparison: PEX-AL-PEX vs PE-AL-PE

A. Comparison of Structural Properties:

PEX-AL-PEX and PE-AL-PE, though seemingly similar, exhibit distinct structural differences which contribute to their respective applications.

PEX-AL-PEX pipes consist of three layers: the inner and outer layers made up of cross-linked polyethylene (PEX), sandwiching a middle layer of aluminum. This unique design combines the advantages of plastic’s flexibility and metal’s strength.

In contrast, PE-AL-PE pipes comprise an inner and outer layer of polyethylene (PE), also with an aluminum core. While the polyethylene layers aren't cross-linked as in the PEX-AL-PEX, they offer great resistance to environmental corrosion.

B. Performance Comparison (Pressure Resistance, Temperature Variability, Durability):

PEX-AL-PEX pipes possess superior pressure resistance, maintaining integrity and function even in high-pressure systems. They are capable of withstanding greater temperature deviations without compromising structural integrity.

PE-AL-PE pipes, although not as robust as PEX-AL-PEX under high pressure or fluctuating temperatures, bring a commendable level of durability to the table. They are suitable for moderate pressure and temperature systems and still offer long-term functionality.

C. Comparison of Installation Processes and Ease of Use:

Both PEX-AL-PEX and PE-AL-PE lay claim to simple installation processes relative to traditional metal pipes. However, PEX-AL-PEX pipes provide a slight edge in terms of flexibility and bendability, aiding in smoother installation around corners and in tight spaces.

PE-AL-PE's rigid nature might require additional fittings for installation in complex layouts, adding to the installation time and costs.

D. Cost-Effectiveness Comparison:

From an economic perspective, both PEX-AL-PEX and PE-AL-PE pipes represent cost-effective solutions; however, individual circumstances dictate which pipe offers the best value.

PEX-AL-PEX pipes, even though they might be pricier initially, can be more cost-effective in the long run, especially for high-pressure and large-scale applications owing to their superior pressure resistance and durability.

PE-AL-PE pipes may be an optimal choice for less demanding systems, considering their reasonable price point and decent performance capabilities.

Conclusion:

Choosing between PEX-AL-PEX and PE-AL-PE pipes isn't a matter of which is better universally, but which is better for your specific needs and circumstances. By taking into account factors such as pressure and temperature requirements, installation complexity, and budget, you'll be armed to make an informed decision. And PE AL PE pipe price is cheaper and enough for gas use, but some market most use PEX AL PEX in gas pipework. Both these two pipes from VPEXCO already get the AS 4176 and ISO17484 Standard approval. And these two gas pipes use the same gas fittings, brass compress fittings and brass press fittings for gas system. And they use the same tools. 

Remember, safety is foremost, and always ensure your gas installation aligns with local regulations and is performed by certified personnel.

Frequently Asked Questions

1.    What’s main difference between PE AL PE and PEX AL PEX gas pipe?

Below table will help you compare these 2 gas pipes easier: