Steel-clad steel steam-insulated pipelines have a wide range of market applications, growing with the vigorous development of urban centralized heating and combined heat and power generation. The technology for thermal pipelines has been widely applied domestically. The buried straight laying method is favored for its excellent insulation performance, high energy-saving efficiency; minimal land occupation, without affecting municipal planning; easy installation, short construction period; long service life, and low maintenance costs. Since its introduction, it has gained widespread popularity. The types of external protective sleeves for buried steam-insulated pipes mainly used in China are "plastic-clad steel" and "steel-clad steel." The technical route for steel-clad steel burial is based on traditional trench laying, replacing brick or concrete trenches with steel sleeves. The sliding interface of the pipeline is the interface between the pipeline support and the inner wall of the steel sleeve. Buried steam pipelines; buried laying; external fixation; internal fixation. In recent years, there have been many attempts to use buried steam pipelines in northern cities. When steam pipelines cross main city roads and involve issues of environmental beautification, the buried laying method can effectively address these problems. It has gained wider application due to its fast construction progress, good insulation performance, low construction cost, and material saving characteristics. As steam buried pipelines are a relatively new phenomenon, the national construction department has not yet formulated formal standards for detailed provisions on steam buried pipelines.

The price of steel clad steel thermal insulation pipes from manufacturers, with their direct-buried steam pipeline features, has gained increasing popularity in the heating industry as a new material due to their advantages such as fast construction progress, excellent thermal insulation performance, low construction cost, and material savings. Since there is no design specification for high-temperature steam pipelines, the insulation structures and fixing methods vary among different manufacturers. This article discusses several common features of direct-buried steam pipelines available on the market.