1. The working pressure of the vacuum pump should meet the ultimate vacuum and working pressure requirements of the vacuum equipment. For example, a vacuum drying process requires a working vacuum of 10mmHg, and the ultimate vacuum of the selected vacuum pump should be at least 2mmHg, preferably 1mmHg. Usually, the ultimate vacuum degree of the pump is selected to be half to an order of magnitude higher than the working vacuum degree of the vacuum equipment.

2. Correctly select the working point of the vacuum pump. Each type of pump has a certain working pressure range, such as: 2BV series water ring vacuum pump working pressure range is 760mmHg~25mmHg (absolute pressure). In such a wide pressure range, the pumping speed of the pump changes with the pressure (for details, please refer to the pump The performance curve), its stable working pressure range is 760~60mmHg. Therefore, the working point of the pump should be selected within this range, and it should not be allowed to work for a long time at 25~30mmHg.

3. Under its working pressure, the vacuum pump should be able to remove all the gas generated in the process of the vacuum equipment.

4. Correctly combine the vacuum pump. Due to the selective pumping of vacuum pumps, sometimes one type of pump cannot meet the pumping requirements, and several pumps need to be combined to complement each other to meet the pumping requirements. For example, the titanium sublimation pump has a high pumping speed for hydrogen, but cannot pump helium, while the three-pole sputtering ion pump (or the two-pole asymmetric cathode sputtering ion pump) has a certain pumping speed for argon. Combined, the vacuum device will get a better vacuum degree. In addition, some vacuum pumps cannot work under atmospheric pressure and require pre-vacuum; some vacuum pumps have an outlet pressure lower than atmospheric pressure and require a fore pump, so they all need to be used in combination.

5. Requirements for oil pollution of vacuum equipment. If the equipment is strictly required to be oil-free, various oil-free pumps should be selected, such as: water ring pump, molecular sieve adsorption pump, sputtering ion pump, cryogenic pump, etc. If the requirements are not strict, you can choose an oil pump, plus some anti-oil pollution measures, such as adding cold traps, baffles, oil traps, etc., can also meet the clean vacuum requirements.

6. Understand the composition of the pumped gas, whether the gas contains condensable vapor, whether there is particle dust, whether it is corrosive, etc. When choosing a vacuum pump, you need to know the gas composition and select the corresponding pump for the gas to be pumped. If the gas contains vapors, particles, and corrosive gases, it should be considered to install auxiliary equipment such as condensers, dust collectors, etc. on the inlet pipeline of the pump.

7. How does the oil vapor discharged from the vacuum pump affect the environment? If the environment does not allow pollution, you can choose an oil-free vacuum pump, or discharge the oil vapor to the outside.

8. Whether the vibration generated by the vacuum pump has any influence on the process and the environment. If the process does not allow, choose a pump without vibration or take anti-vibration measures.