海底单层保温管节点防水密封试验研究

海底单层保温配重管现场节点的防护与填充是保障海底管道安全运行的关键。文章对海管现场节点的两种补口结构(防水帽+热缩带(焊口)+聚氨酯保温半瓦+高强聚氨酯泡沫填充结构;防水帽+热缩带(焊口)+高强聚氨酯泡沫填充结构)进行了20、40 m水深条件下的防水密封性试验研究,同时开展了其在60 m水域内的适用性研究。结果表明,上述两种节点补口结构可在40 m水域内安全运行;热熔胶型防水帽可用于40～60 m水深;现有单层保温管的保温层抗压强度仅为0.2 MPa,不适用于60 m水深的海底管道。

Experimental Research on Waterproof Seal of Field Joint of Submarine Single Layer Insulation Pipeline

The protecting and filling technology for the field joint of a submarine single layer insulation and weighted pipeline is the key point for the safe operation of the pipeline.Two field joint coating structures,i.e.the waterproof cap + thermal shrinkable tape + polyurethane insulation semi-tile + high strength polyurethane foam filling and the waterproof cap + thermal shrinkable tape + high strength polyurethane foam filling,applied in the single layer insulation and weighted pipeline were tested on their waterproof seal properties at the water depths of 20 m and 40 m.Research about the adaptability of these structures at the water depth of 60 m was carried out at the same time.The test results showed that these two structures were safe within the water depth of 40 m,the hot melt adhesive type waterproof cap could be applied at the water depths of 40 ～ 60 m,the thermal insulation layer compression strength of the existing single thermal insulation layer pipeline was 0.2 MPa only and was inapplicable to pipeline at the water depth of 60 m.