Spiral steel pipes are extremely important piping materials in modern industry. Due to their high structural strength, convenient construction, and good cost - effectiveness, they are widely used in many fields such as petroleum, natural gas, water conservancy, and construction. Spiral steel pipes of different diameters can meet different engineering requirements. The following will describe the application scenarios and technical characteristics of medium - diameter spiral steel pipes (DN200 - DN1000) in various fields.

Medium - diameter spiral steel pipes (DN200 - DN1000) are the most commonly used among spiral steel pipes of different diameters. They take into account both transportation efficiency and construction flexibility and are often seen in the energy and infrastructure fields.

Petroleum and natural gas transportation: Spiral steel pipes with DN400 - DN800 are key materials for long - distance pipelines. For example, in the West - to - East Gas Transmission Project, a large number of spiral welded pipes made of X70 material with a wall thickness of 10 - 12 mm are used, and their working pressure can reach more than 10 MPa. These steel pipes must undergo strict ultrasonic flaw detection and anti - corrosion coating treatment.

Thermal power pipe network: In urban central heating systems, spiral steel pipes with DN500 - DN900 are generally adopted, and the inner wall should be lined with high - temperature - resistant materials (such as polyurethane foam) to reduce heat loss. In the north, the temperature difference in winter is large, and the steel pipes need to have low - temperature toughness to prevent brittle fracture.

Bridge and building structures: During the construction of large - scale stadiums, spiral steel pipes with DN600 or above can be used as pile foundations or support columns. Some piers of the Hong Kong - Zhuhai - Macao Bridge adopt a double - layer spiral steel pipe structure, and concrete is poured inside to improve the bearing capacity.