In the first stage of a pumping cycle the cylinder is filled with steam from the boiler. Then cold water is sprayed into the cylinder causing the steam to condense and creating a partial vacuum inside the cylinder.

• 在一个抽水循环的第一阶段，圆筒内将装满来自锅炉的蒸汽，然后冷水将喷入圆筒中，以便蒸汽冷凝之后在圆筒内形成部分真空。