内衬双金属复合管紧密度测量及影响因素

介绍了双金属内衬复合管的成型工艺及主要成型方法,分析了双金属复合管在液压成型后,内、外层钢管的受力状态。根据变形协调条件,得出复合管内外层残余接触压力与残余接触应力的正相关关系式。依据滑动摩擦原理,提出了通过测量内外层间的推脱力,替代API SPEC5LD推荐的测量残余接触应力计算紧密度的方法。最后分析了紧密度的影响因素,即紧密度的大小受复合管成型液压压力、后续涂敷温度和现场试压压力的影响。

Tightness Measurement and Influencing Factors of Bimetal Composite Pipe with Lining

In this article, it mainly introduced forming process and the main forming methods for bimetal composite pipe with lining, and analyzed stress state of the inner pipe and outer pipe after hydroforming. On the basis of deformation compatibility condition,the positive correlation relation obtained between the residual contact pressure and the residual contact stress of the inner pipe and outer pipe. According to the principle of sliding friction, the new tightness calculation method by measuring force pushing out the liner pipe was proposed. This can replace the tightness test method recommended in API 5LD Specification. Finally, the influence factors to tightness were analyzed, such as hydraulic pressure, the subsequent coating temperature and field test pressure.