热煨弯管单层FBE 外缠聚乙烯复合带防腐技术

热煨弯管形状特殊，适用于地形起伏相对较大、道路状况较差区域的天然气管道敷设施工，但其在运输过程中易受到磕碰撞击，因此，要求热煨弯管应具有良好的防腐、耐磨和抗冲击性能。为此，对目前国内外常用的热煨弯管防腐形式在现场应用的效果、防腐性能等方面进行了对比分析，针对热煨弯管因运输、现场布管等多种原因容易造成防腐层损坏，增加了现场补伤工作量、降低了防腐性能的问题，提出了新的防腐结构：热煨弯管单层FBE 外缠聚乙烯复合带，即将单层FBE 防腐结构和聚乙烯复合带防腐结构这两种防腐形式相结合，以提高防腐层的抗冲击能力和耐磨性。具体做法：热煨弯管喷砂除锈后聚乙烯复合带防腐结构中的静电喷涂环氧粉末厚度由150 μm 提高到400 μm，形成单层FBE 防腐层；再在作业线上由缠绕机缠绕聚乙烯复合带形成防护层，从而提高热煨弯管最终的整体防腐质量。现场应用效果表明，该新型防腐结构的剥离强度高、抗冲击性能好，能满足长途运输及施工现场恶劣环境的要求。

Anti-corrosion technology for heat-bending bends by winding polyethylene composite straps on monolayer FBE

A heat-bending bend, with a special shape, is applicable to gas piping in the areas under the larger topographic relief and poorerroad conditions. In the process of transportation, however, due to its vulnerability to collision and impact, it should be good in anti-corrosiveperformance, abrasion resistance and impact resistance. In this paper, a comparative analysis was performed on the globally commonanti-corrosion methods for heat-bending bends in terms of field application and anti-corrosive performance. Anti-corrosion insulations areeasily damaged by multiple reasons during the transportation and field laying of heat-bending bends, as a result, the field repair load isincreased and the anti-corrosive performance is also spoilt. Therefore, a new anti-corrosion structure was proposed to wind the monolayerFBE of heat-bending bends with polyethylene composite straps. That is to say, the impact resistance and abrasion resistance of anti-corrosioninsulations are improved by combining two corrosion forms (i.e., monolayer FBE and polyethylene composite strap) with each other.In details, monolayer FBE anti-corrosion insulations are formed when the epoxy powder in the anti-corrosive structures of polyethylenecomposite straps thickens to 400 μm from 150 μm after sandblasting and derusting of heat-bending bends. Then, protective layers areformed by winding polyethylene composite straps on the operation lines with a winding machine. In this way, the overall anti-corrosionperformance of heat-bending bends is ultimately improved. Field application proves that this new anti-corrosion structure is characterizedby high peel strength and good impact resistance and that it can meet the requirements of the long-distance transportation and the adverseconstruction site environment.