Can Black Steel Pipe be Used for Gas?

Can I use black steel pipe for gas?

Absolutely not. Black steel pipe should never be used directly for gas piping, especially in indoor gas systems. The core reason is that black steel pipe is extremely susceptible to rust, and rust can have catastrophic consequences. Gas-specific pipes, on the other hand, are professionally treated with 3PE anti-corrosion treatment immediately after leaving the factory.

Why should black steel pipe never be used for gas?

Black steel pipe is a type of carbon steel pipe with a black oxide scale on the surface, uncoated, and prone to rust, but it is also high-strength and low-cost. It is a "semi-finished product" or "base material," and its value often depends on subsequent anti-corrosion treatment or use in dry environments. If the environment is dry or if treatments such as painting are planned, it is a cost-effective option. If direct exposure to humidity is required, galvanized or stainless steel pipe should be selected.

Possible consequences of using black steel pipe directly for gas:

1. Safety hazards - gas leaks and explosions

Internal rust: Gas often contains traces of moisture. Without internal rust protection, black steel pipes can rust from the inside. Rust flakes off, potentially clogging valves and gas stoves and thinning the pipe walls. Eventually, pressure can cause perforations or ruptures in the pipes, leading to gas leaks. When the gas mixes with air and encounters an open flame, it can explode.

External Rust: In humid environments like kitchens and manholes, the exterior of black steel pipes can quickly rust, weakening the pipe walls.

2. Contamination of Gas Appliances
Stripped rust can travel with natural gas and enter and damage precision equipment like gas meters, gas stoves, and water heaters.

3. Violation of Mandatory National Regulations
China's "Urban Gas Design Code" (GB50028) and other national standards clearly mandate that indoor gas piping must use corrosion-resistant materials such as galvanized steel, stainless steel, and copper. Black steel pipes do not meet safety regulations and will not pass any formal safety inspection.

What is the correct material for natural gas piping? 

Depending on the usage scenario, the correct choice is as follows:

1. Indoor natural gas piping (from the riser to your stove and water heater)

Preferred: Stainless steel corrugated hose
Advantages: Excellent flexibility, excellent corrosion resistance, easy installation, and maximum safety. This is the mainstream and recommended choice for home renovations.

Traditional Choice: Galvanized steel pipe
Advantages: High strength, protected by a galvanized coating compared to black steel pipe.
Disadvantages: Requires threading for installation, and joints are vulnerable to rust, making stainless steel pipe a growing alternative.

High-end Choice: Thin-walled stainless steel or copper pipe
Advantages: Stable performance, extremely long lifespan, and durable aesthetics.

Important: Even galvanized steel pipe must be a dedicated product that complies with gas regulations and must be installed by professionals.

2. Outdoor buried natural gas mains

The use of black or galvanized steel pipe is strictly prohibited. The soil is highly corrosive and will quickly damage the pipe. You must use: PE polyethylene plastic pipe or 3PE anti-corrosion steel pipe (three layers of polyethylene reinforced anti-corrosion coating on the outside of the steel pipe). These are specifically designed for buried gas transmission.

Final Recommendation:
If you are considering renovating or upgrading your natural gas pipeline, immediately discontinue any thoughts of using black steel pipe! The installation and material selection of natural gas pipelines affect the safety of you and your family and property. They must be installed by a qualified natural gas company or professional team in strict accordance with regulations.

If you discover that your existing natural gas pipeline is black steel pipe and is rusted, please contact your local natural gas company immediately for professional inspection and replacement. Safety is paramount; never take chances.

Read more: Carbon Steel vs Black Steel or Schedule 40 Black Steel Pipe