姐姐8免费观看完整版电视剧,电影三级迅雷,谁有农村版的黄色小说求介绍,韩国电影大胸的女友,男人狂躁女人下面全程,好爽又高潮了毛片无广告,封先生的溺宠甜妻是哪个小说,第11部分夫妇交换系列,花娇希韵小说全文免费阅读起点

WLW Vertical oil-free vacuum pump Oil-free (corrosion-resistant) vertical reciprocating vacuum pump is a replacement product of W-type horizontal vacuum pump, which is the main equipment for obtaining rough vacuum. The complete isolation of the crankcase and the cylinder is achieved by the use of a fully sealed device; the piston ring is self-lubricating and achieves oil-free lubrication. Because there is no sewage discharge, this type of vacuum pump is especially suitable for vacuum distillation, vacuum evaporation, vacuum drying, vacuum concentration, vacuum impregnation and other processes in the chemical, pharmaceutical and food industries.