valve housing短语¹⁸⁰⁰⁹⁸⁺¹ 基本例句 阀套 In order to prevent the topside valve housing of the plunger from breaking and increase the pumping efficiency, we analysed the texture and material of the original and find its failure. 为了防止抽油泵柱塞上凡尔罩断脱，提高抽油泵泵效，对原抽油泵柱塞上凡尔罩结构及材质进行了分析。 cnki