规范规定:采暖管道穿过墙壁,应设置铁皮或钢制套管,其两端应与饰面相平。但在实际工作中,经常可以见到采暖套管突出饰面或因长度不足不能与饰面相平的情况。如果套管长度过短,在冬季采暖时,管道热胀伸长会破坏套管周边的抹灰;套管过长也会影响墙面的美观。按通常的作法,套管长度—般为墙体厚度加上两侧饰面抹灰厚度,而砌筑时,墙体的垂直度、平整度等一般均存在偏差,虽然仍在允许范围内, The code stipulates that heating pipes should pass through the walls, and iron sheets or steel sleeves should be provided, and their ends should be flush with the finishes. However, in actual work, it is often seen that the heating sleeve protruding finish or the lack of length can not be flat with the finish. If the length of the casing is too short, thermal expansion of the pipeline will damage the plaster around the casing during heating in winter. The long casing will also affect the appearance of the wall. According to the usual practice, the length of the casing is generally the thickness of the wall plus the thickness of the plastering on both sides. In the masonry, the verticality and flatness of the wall generally have deviations, although still within the allowable range.