In order to achieve the best configuration, when selecting the vacuum system, the vacuum pump selection shall consider the following points:

1. The limit pressure of the vacuum pump shall fully meet the working pressure of the production process. Generally, the limit pressure of the selected pump is about an order of magnitude lower than the production process requirements.

2. Each pump has a certain working pressure range. Therefore, the working point of the pump should be selected within this range, rather than allowing it to work at the allowable working pressure for a long time.

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

4. Select vacuum unit:

(1) When the use of one pump can not fully meet the requirements of air extraction and vacuum, several pumps must be combined and supplemented to meet the production process requirements.

(2) Some vacuum pumps can not work under atmospheric pressure and must be pre vacuum; The outlet pressure of some vacuum pumps is lower than the atmospheric pressure, so the front stage pump must be used, so the pumps must be matched and combined. The vacuum pump used in combination is called vacuum pump unit, which can make the vacuum system obtain better vacuum degree and exhaust volume. We should correctly and reasonably select the combined vacuum pump, because different vacuum pumps have different requirements for the extracted gas. For example, roots rotary vane unit is not suitable for the system containing more condensable gas in general.

5. When you choose an oil sealed pump, you should first understand whether your vacuum system has requirements for oil and air pollution. If the equipment is strictly required to be free of oil, various non oil pumps shall be selected, such as water ring pump, cryogenic pump, etc. If the requirements are not strict, the oil pump can be selected, and some oil and air pollution prevention measures, such as adding cold trap, oil retaining trap, baffle, etc., can also meet the requirements of clean vacuum.

6. Understand the composition of the extracted gas, whether the gas contains condensable steam, whether there is particulate dust, whether it is corrosive, etc. When selecting a vacuum pump, you must know the gas composition and select the corresponding pump for the pumped gas. If the gas contains steam, particles and corrosive gases, it shall be considered to install auxiliary equipment on the air inlet pipeline of the pump, such as condenser, dust collector, etc.

7. When selecting an oil sealed vacuum pump, consider the impact of the oil vapor (oil fume) discharged by the vacuum pump on the environment. If air pollution is not allowed in the environment, an oil-free vacuum pump shall be selected, or the oil steam shall be discharged outdoors.

8. Whether the vibration generated during the operation of the vacuum pump has any impact on the production process and environment. If the production process is not allowed, the pump without vibration shall be selected or anti vibration measures shall be taken.

9. Price, operation and maintenance cost of vacuum pump.

After considering various situations, you can finally determine a solution suitable for you:

(1) Minimum investment cost.

(2) Minimum production and operation cost.

(3) It is a feasible scheme to distribute the first two cases reasonably and evenly.