真空机组先启动SK-30水环真空泵带压力降到6.5 KPa（此时真空机组的抽速是SK-30的抽速）启动ZJP-1200（此时真空机组的抽速是ZJP-1200抽速）待压力降到4 KPa启动ZJP2500（此时真空机组的抽速是ZJP-2500抽速）待压力降到1kpa时最后启动ZJP5000（此时真空机组的抽速是ZJP-5000抽速）到100Pa达到使用真空度时时就可以关闭机组-Vacuum unit first start SK-30 water ring vacuum pump with pressure drops below 6.5 KPa (pumping speed of the vacuum unit at this time is SK-30 pumping speed) start ZJP-1200 (pumping speed of the vacuum unit at this time is ZJP-1200 pumping speed ) until pressure drops below 4 KPa start ZJP2500 (pumping speed of the vacuum unit at this time is ZJP-2500 pumping speed) until the last start when pressure drops 1kpa ZJP5000 (pumping speed of the vacuum unit at this time is ZJP-5000 pumping speed) to 100Pa achieved using vacuum unit can be closed from time to time