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A. Add water before starting the circulating water multi-purpose vacuum pump. Do not run empty.

B. The rubber tube on the back of the box of the circulating water type multi-purpose vacuum pump is used for changing water without stopping the machine. When the water needs to be changed due to long-time work and the water temperature rises, the upper mouth of the hose is pulled out, and the hose is connected with the tap water; after opening, the waste water is discharged from the upper hole of the box.

C. Connect the vacuum vessel with the vacuum pipe of the circulating water multi-purpose vacuum pump

1. Single tube pumping: grouping experiment; each vent is connected with a container.

2. Parallel pumping: if the vacuum of a larger container is pumped, a special connector can be used in parallel to shorten the pumping time.

D. Use of external circulating water:

When the equipment of circulating water type multi-purpose vacuum pump works normally, it is not necessary to open the external circulating water. If it is necessary to provide cooling water to the reaction device, the water outlet of the external circulating water is connected with the water inlet of the reaction device with a water pipe. The water outlet of the reaction device is connected with the water inlet of the external circulating water, and the external circulating water switch can be opened.