1、The working pressure of the vacuum pump should meet the ultimate vacuum and working pressure requirements of the vacuum equipment. For example, if a vacuum drying process requires a working vacuum of 10 mmHg, the selected vacuum pump's ultimate vacuum should be at least 2 mmHg, ideally reaching 1 mmHg. Typically, the pump's ultimate vacuum should be one to half an order of magnitude higher than the working vacuum of the vacuum equipment.

2、Select the operating point of the vacuum pump correctly. Each pump has a certain range of operating pressure. For example, the operating pressure range of the 2BV series liquid ring vacuum pump is 760 mmHg to 25 mmHg (absolute pressure). Within this wide pressure range, the pump's pumping speed varies with pressure (refer to the pump performance curve for detailed changes), and its stable operating pressure range is 760 to 60 mmHg. Therefore, the pump's operating point should be selected within this range, rather than allowing it to operate long-term at 25 to 30 mmHg.

3、The vacuum pump should be able to exhaust all the gas generated during the vacuum equipment process under its working pressure.

4、Properly combine vacuum pumps. Since vacuum pumps have selective pumping capabilities, sometimes using one type of pump may not meet the pumping requirements, and several pumps need to be combined to complement each other to meet the pumping requirements. For example, a titanium sublimation pump has a high pumping speed for hydrogen but cannot pump helium. In contrast, a triode sputtering ion pump (or bipolar asymmetrical cathode sputtering ion pump) has a certain pumping speed for argon. Combining the two will improve the vacuum degree of the vacuum device.

5、Consider the vacuum equipment's requirements for oil pollution. If the equipment strictly requires no oil, various oil-free pumps should be selected, such as water ring pumps, molecular sieve adsorption pumps, sputtering ion pumps, and cryogenic pumps. If the requirements are not strict, oil pumps can be selected, supplemented with measures to prevent oil pollution, such as adding cold traps, baffles, and oil traps, to meet the cleanliness requirements of the vacuum.

6、Understand the composition of the pumped gas, whether it contains condensable vapor, particulate dust, corrosiveness, etc. When selecting a vacuum pump, it is necessary to know the gas composition and choose the appropriate pump accordingly. If the gas contains vapor, particles, and corrosive gases, auxiliary equipment should be installed on the pump's intake pipeline, such as condensers and dust collectors.

7、Consider the impact of the oil vapor discharged by the vacuum pump on the environment. If the environment does not allow pollution, oil-free vacuum pumps can be selected, or the oil vapor can be discharged outdoors.

8、Consider whether the vibration generated by the vacuum pump during operation affects the process and the environment. If the process does not allow it, select a pump without vibration or take anti-vibration measures.

9、Consider the price, operation, and maintenance costs of the vacuum pump.