After the repair, the technician had to re-pressurize the water tank.

re-pressurize 是由前缀 re-（表示"重新"）和动词 pressurize（加压）组成的复合动词。pressurize 本身来自名词 pressure（压力）加上动词后缀 -ize（使...化）。re-pressurize 字面意思是"重新加压"，指将压力恢复到正常水平。