特殊用法atmospheric topping1.常压拔顶(在常压蒸馏塔中蒸馏轻质石油产品)high topping1.截头高立木(截去树头用作架空索道的立柱)single topping1.单面贴胶vacuum topping1.减压拔顶蒸馏topping of crude oil1.原油拔顶; 原油的直接蒸馏