直埋热水保温管道接头补口工艺改进与应用

分析直埋热水保温管道接头补口常规工艺存在的问题。对改进后的补口结构、施工工艺、优势进行探讨,分析实际应用效果。改进工艺将常规工艺中分段式热缩收带密封改进为热收缩套(非剖开型)密封,消除了热收缩带与PE外护管粘接处易受工作钢管热伸长影响,导致的开裂问题。将常规工艺中暴露在土壤环境中的聚氨酯注料口、排气孔包裹在热收缩套内,杜绝了渗水问题。热收缩套与PE外护管粘接处采用PET打包带、不锈钢丝加固密封,耐酸碱性强,可经受地下水的侵蚀,保证了密封效果。应用在完全浸没在河水中的直埋热水保温管道中,自2011年至今接头补口未发生泄漏。

Improvement and Application of Joint Coating Technology for Directly Buried Hot Water Insulation Pipeline

The problems existing in the conventional technology for directly buried hot water insulation pipeline joint coating are analyzed. The joint coating structure,construction technology and advantages of the improved technology are discussed,and the actual application effect is analyzed. The improved process changes the segmented heat shrinkable tape seal in the conventional process to a heat shrinkable sleeve( nonsplit type) seal,which eliminates the cracking problem easily caused by the thermal elongation of the working steel tube at the bonding place between the heat shrinkable tape and the PE outer protective tube. The polyurethane injection port and exhaust hole exposed to the soil environment in the conventional process are wrapped in the heat shrinkable sleeve,which eliminated the water seepage problem. The bonding place between the heat shrinkable sleeve and the PE outer protective tube is reinforced and sealed by PET packing tape and stainless steel wire. It has strong acid and alkali resistance and can withstand the erosion of groundwater to ensure the sealing effect. It has been applied to directly buried hot water insulation pipeline completely immersed in river water. No leakage has occurred at the joint coating since 2011.