The market application scope of steel sleeve steel steam insulated steel pipes is expanding rapidly with the development of urban centralized heating and cogeneration, and thermal pipeline technology has been widely used in China. The direct burial laying method has good insulation effect and high energy-saving efficiency; Less land occupation, without affecting municipal planning; Easy installation and short construction period; The advantages of long service life and low maintenance costs have been widely favored since their appearance. At present, China mainly uses two types of outer protective sleeves for directly buried steam insulation pipes: "plastic sleeve steel" and "steel sleeve steel". The technical route for burying steel sleeves is to replace brick or concrete trenches with steel sleeves on the basis of traditional trench laying. The sliding interface of the pipeline is the interface between the pipeline support and the inner wall of the steel casing. Directly buried steam pipelines; Direct burial; External fixation; In recent years, many attempts have been made to directly embed steam pipelines in northern cities for internal fixation. When steam pipelines cross urban main roads and involve environmental beautification issues, the direct burial laying method can effectively solve the above problems, and has been increasingly widely used due to its fast construction progress, good insulation performance, low engineering cost, and energy-saving building materials. Due to the fact that steam buried pipelines are a new phenomenon, the national construction department has not yet formulated formal standards to provide detailed regulations for steam buried pipelines.

Several characteristics of direct buried steam pipelines, such as fast construction progress, good insulation performance, low engineering cost, and saving building materials, are increasingly widely used as emerging materials in the heating industry. Due to the lack of design specifications for high-temperature steam pipelines, their insulation structures and fixing forms vary from manufacturer to manufacturer. This article provides a special discussion on several commonly used buried steam pipelines in the market.