聚氨酯保温管“管中管”成型工艺及质量控制

Moulding Process for Pipe-in-Pipe of Polyurethane Insulation Pipe and its Quality Control

大口径预制直埋保温管属于地下工程,一旦投入运行,管道的检测维修都很困难而且成本较高,保温管的质量是影响整个工程质量的关键因素之一。为提高保温管的预制质量,结合大口径高密度聚乙烯外护层保温管的"管中管"生产工艺以及实际的生产过程,以油气运输用管道三层PE防腐处理为例,从三层PE防腐层的涂敷、高密度聚乙烯外护管的生产、聚氨酯泡沫塑料保温层的生产、防水帽的安装和成品管出厂检验等方面,在遵循相关标准规范的基础上,提出了硬质聚氨酯泡沫塑料层保温管生产过程中需注意的问题,可最大限度地保证保温管的质量,进而保证工程质量。

Directly berried insulated pipelines with large diameter are of underground facilities. After these pipelines are put into operation, their inspection and maintenance are very difficult and the costs for inspection and maintenance are also very high, so quality of the pipelines is one of the key factors affecting overall construction quality. In order to improve quality of the pipelines, combined with fabrication technology and actual fabrication process of pipe-in-pipes with large diameter and external high density polyethylene coating, taking 3-layer PE corrosion control coating for oil and gas pipelines as an example, described are construction of 3-layer PE corrosion control coating, fabrication of pipes with external high density polyethylene coating and polyurethane foaming plastic insulating layer, installation of tarpaulins and factory inspection of product pipes and put forward are considerations in fabrication process of insulated pipes with hard polyurethane foaming plastic insulating layer according to requirements in relative codes, standards and specifications, which can ensure quality of the insulated pipes as far as possible and ensure project quality accordingly.