Steel-clad steel steam-insulated pipes have a wide range of market applications, expanding 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 direct-burial laying method is favored for its excellent insulation performance, high energy-saving efficiency, minimal land use without affecting urban planning, ease of installation, short construction period, long service life, and low maintenance costs. The types of external sheath for direct-buried steam-insulated pipes commonly 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-clad pipes. The sliding interface of the pipeline is the interface between the pipeline support and the inner wall of the steel-clad pipe. Direct-buried steam pipelines; direct burial; external fixation; internal fixation. In recent years, there have been many attempts to use direct-buried steam pipelines in northern cities. When steam pipelines cross city main roads or involve environmental beautification issues, the direct-burial laying method can effectively solve these problems, and it has gained more widespread application due to its fast construction progress, good insulation performance, low construction cost, and material savings. As a new phenomenon, the construction department of the state has not yet formulated formal standards for detailed provisions on direct-buried steam pipelines.

Several characteristics of steel-clad steel-insulated steam pipeline manufacturers' prices for directly buried steam pipelines make them increasingly popular as a new material in the heating industry. They are favored for their fast construction progress, excellent insulation performance, low construction cost, and material savings. As there is no design specification for high-temperature steam pipelines, the insulation structures and fixation methods vary among manufacturers. This article discusses several common types of directly buried steam pipelines available on the market.