浅谈聚乙烯防腐夹克的质量问题
Preliminry Views on Quality of Anticorrosi ve Polyethylene Jacket
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- DOI:
- 作者:
- 黄其兴, 田广墅
Huang Qixing, Tian Guangshu
- 作者单位:
- 石油部施工技术研究所
- 关键词:
- 摘要:
- 本文根据聚乙烯夹克耐环境应力开裂的基本理论,分析了华北油田提供的“埋地输油管线φ529mm 黄夹克开裂现状”的书面报告,提出了聚乙烯夹克的开裂不仅仅是工艺问题,环境和材料也是导致开裂的重要因素,因此,防止夹克开裂应从以下三个方面考虑:1.改进材质,主要途径是①采用分子量分布适应的低、中密度聚乙烯;②高、低密度聚乙烯共混;③选用共聚性聚乙烯。2.改善底胶,主要途径是以聚乙烯为主剂与其他助剂制成或者在底胶中加入“应力抑制剂”。3.改革工艺,途径是①表面处理除清除钢材表面附着物外,还应在钢材表面造成一定深度的锚纹;②应开展分段冷却工艺的研究,③施胶和包覆工艺要进行改进,可采用充臭氧施胶工艺和负压包覆。
In‘the light ol mechmcs, the author analysis such phenomenon and thinks that the rapture toughness of pipeline,the shape of crack ,the level of circulatory pressure and the pressure reserve time a re major factors which influence the crack extension a nd pressu re re ve rsal . The author aIso suggests pressure test should be done in sections with high pressure and limited pressure or stress below its stable extension curve for intermittent transmition pipeline.That is the engineeri ng measures which reduce stability extention of crack andpressure reversal by using high testing pressure，low operation pressure and increasing safety coefficient Baled on the theory of enviromental stress cracking of PE jacket，the authors analyse theCracking reasons of PE yellow packet applied to underground oil Pipeline ln Huabei Otl Fieldand consider that resides the detects of coati rig process，the enviroment and raw materialsare the lm portant cracks rig reasons too。In such case, the following 3 measures Ior proven-ttng PE Jacket cracking shoud be adopted; l.improving raw materials:1 using low andmedium denstty PE of dtstributrig adaptaUon of molecular weight.、2; ming-low andmedium denseity PE together.;3 using copolyethylene .2.lm prov ing t he properties of baseadhesrve, taking PE as main agent and mixing it with.suitable admixture or adding stre-ss inhibitur“into the base adhesive: 3. modlfying production Itne;1 besides cleaning t heattached substances Irom metal surface, the required depth of anchor must be glven: 2coollng the coated pipe in sections;3: improving process of appl ying adhesi ve and coati rigs，using the technique of oxi gen-fillled applying adhesive and negtive pressure wrapping.1987,1(1): 6-10参考文献：
[1]苏联发明证书1.070,375
[2](美)Lustiger, A;M a rkha m .R ,L; 《Polym er》1983.VO124.No.12
[3]法国专刊:2,506.663.
[4]澳大利亚专利:369,771