When Should You Use Yellow or Black Underground Gas Pipes?

Choosing the correct piping material is one of the most critical decisions in any gas line installation. Although function is king, the colour of the pipe is a key to safety and lasting performance. For an underground gas pipe, the decision is usually yellow or black. This isn’t simply a visual bias, either, but rather a safety guideline to safeguard infrastructure and lives. Knowing which colour is used for what is key in compliance and safe gas distribution. This guide will break it all down and assist you in deciding when to use yellow vs. black pipes for your project.

Understanding Underground Pipe Colour Codes

Before diving into the specifics of gas pipes, it’s important to understand the universal colour-coding system for underground utilities. This system was established to prevent accidental damage during excavation, which could lead to service outages, costly repairs, or dangerous accidents. According to the American Public Works Association (APWA), there is a uniform colour code to help workers identify buried lines before they dig [1]. Knowing what pipes are for gas lines and other utilities is the first step in project safety.

The standard colour markings are as follows:

• Red: Electric power lines, conduits, and cables.
• Orange: Telecommunication lines, alarm or signal lines, and fibre optics.
• Yellow: Gas, oil, steam, petroleum, or other flammable materials.
• Green: Sewage and drain lines.
• Blue: Potable (drinking) water.
• Black: Used for specific applications, such as pipes requiring UV resistance when exposed to sunlight.

This colour-coding system acts as a silent but clear form of communication. For anyone planning to excavate, these colours provide an immediate visual warning of what lies beneath the surface, ensuring that sensitive lines like gas pipes are handled with the necessary caution.

When to Use Yellow Underground Gas Pipes

The most common colour you will see for gas distribution is yellow. The yellow gas pipe is the industry standard for both natural gas and Liquefied Petroleum Gas (LPG) applications when the pipes are buried. The primary reason for this is visibility.

The bright yellow colour makes the pipe highly conspicuous against the soil. This immediate visual identification is a critical safety feature. If anyone is digging in the vicinity in the future, the yellow pipe serves as an unmistakable warning that a potentially hazardous gas line is present. Most yellow gas pipes are made from high-density polyethylene, or PE pipe. This material offers several key advantages:

• High Visibility: The distinct yellow colour is easily recognizable, significantly reducing the risk of accidental strikes during excavation.
• Corrosion Resistance: Polyethylene is a polymer that is inert to the chemical and soil conditions that cause metal pipes to rust or corrode. This ensures a long, maintenance-free service life for the system.
• Flexibility: PE pipes have a degree of flexibility, allowing them to withstand ground movement and settling without breaking.

For nearly all standard buried gas line installations, a yellow PE pipe is the correct and safest choice.

When to Use Black Underground Gas Pipes

While yellow is the standard for buried lines, there are specific situations where a black gas pipe is required. The key difference lies in its composition. Black PE pipes are manufactured with carbon black, a material that gives the pipe its colour and, more importantly, provides excellent protection against ultraviolet (UV) radiation.

Sunlight emits UV rays that can degrade standard polyethylene over time, making it brittle and prone to failure. Therefore, a black gas pipe is the appropriate choice for any portion of a gas line system that is exposed to sunlight. This includes:

• Above-ground risers connecting the buried line to a meter.
• Piping that runs along exterior walls or across rooftops.
• Installations in areas where the pipe may be temporarily exposed for extended periods.

Beyond its UV resistance, black PE pipe also boasts high compressive and tensile strength, making it a durable and robust option for these exposed applications.

Trust LESSO for Your Gas Piping Needs

Whether your project requires yellow buried lines or black UV-resistant pipes, having a reliable supplier is crucial. LESSO has established itself as a global leader in high-quality piping solutions, offering a comprehensive range of products for gas distribution systems.

LESSO provides top-tier PE pipe solutions in both yellow and black, engineered to meet the strictest international safety and performance standards. The company’s commitment to innovation means customers have access to modern piping technologies, including flexible pipe for gas and advanced Aluminium-plastic Composite Pipe systems, providing versatile options for various installation challenges.

Furthermore, a gas line is only as strong as its weakest link. That is why LESSO also manufactures a complete selection of durable gas pipe fittings. These fittings are designed to create secure, leak-proof connections, ensuring the integrity of the entire system. By choosing LESSO, you are not just purchasing a product; you are investing in a complete and reliable solution for your underground gas pipe project, backed by decades of industry expertise and a commitment to safety and quality. So, come to contact LESSO for your pipe needs.