What materials are commonly used for long-distance natural gas pipelines?

Posted by zora li on June 4th, 2024

What materials are commonly used for long-distance natural gas pipelines?

Compared with traditional energy sources such as coal and oil, natural gas not only has a high calorific value, but is also more environmentally friendly and low-carbon. In order to transport natural gas from distant production areas to user terminals economically, efficiently, safely and smoothly, high-pressure pipeline transportation technology has developed rapidly in the past 40 years. At present, the total length of natural gas pipelines in the world has exceeded more than 1.5 million kilometers, and the total mileage of natural gas pipelines in my country has also exceeded 100,000 kilometers.

The density of natural gas is about 0.6 times that of air. It is a low-density gas with a large volume at normal temperature and pressure. In order to improve transportation efficiency, save transportation costs, reduce leakage risks, and reduce losses during loading and unloading, natural gas needs to be compressed into a high-pressure state for transportation.

High-pressure natural gas is flammable and explosive. When it is transported on a large scale, over long distances, and uninterruptedly, the pipeline must withstand very high internal pressure. At this time, rupture or leakage in any part may cause significant economic losses or even cause public safety accidents. Therefore, in the design and operation of long-distance natural gas pipelines, it is necessary to ensure the safety and economy of transportation by reasonably selecting pipeline materials and increasing pipeline gas transmission capacity.

The material of the natural gas pipeline must be reliable and durable. Seamless steel pipes are the most commonly used material for long-distance natural gas pipelines because of their high strength, good sealing and anti-aging properties, and the ability to withstand large pressure and temperature changes. The durability of seamless steel pipes mainly depends on the manufacturing process, anti-corrosion treatment and construction quality. Although the price of seamless steel pipes is relatively high, they have a long service life, low maintenance costs, and simple installation processes, and are generally more economical.

Non-metallic and composite pipes can also be used for natural gas pipelines. Non-metallic and composite pipes are light, easy to install, and corrosion-resistant, but they have low strength and are prone to aging. Therefore, they are mainly used for low-pressure pipelines in natural gas transmission branches.