1. It should be clear that whether the vibration generated by the vacuum pump has effect on the process and environment. If the process does not allow it, choose a non-vibrating pump or take anti-vibration measures.
2. Understand the components of the gas being pumped. Such as, whether the pumped gas contains condensable vapors or particles of dusts. Whether the gas corrosive or not. When selecting a vacuum pump, you need to know the gas composition and then select the appropriate pump according to the pumped gas. If the gas contains vapors, particles, and corrosive gases, additional equipment such as condensers, dust collectors, etc., should be installed on the inlet line of the pump.
3. The vacuum pump should be able to drain all the gas generated during the vacuum equipment process under its working pressure.
4. The correct combination of vacuum pumps. Due to the selective pumping of the vacuum pump, a pump may sometimes do not meet the pumping requirements. So, several types of pumps are required to be combined to meet the pumping requirements by support each other.
For example, the titanium sublimation pump has a high pumping speed for hydrogen, but it cannot pump helium, and a three-pole sputtering ion pump (or a bipolar asymmetric cathode sputtering ion pump) has a certain pumping speed for argon. The combined of these two pumps will ensure the vacuum device a better degree of vacuum.
In addition, some vacuum pumps cannot work under atmospheric pressure and they require pre-vacuum; some vacuum pumps have lower outlet pressures than atmospheric pressure and need a backing pump, so they all need to be combined.
5. Vacuum equipment requirements for oil pollution. If the equipment strictly requires no oil, various oil-free pumps should be used, such as water ring pumps, molecular sieve adsorption pumps, sputter ion pumps, cryogenic pumps, etc. If the requirements are not strict, oil pumps should be used with some oil pollution prevention measures such as cold traps, baffles, and oil traps...
6. Correctly select the working point of the vacuum pump. Each pump has a working pressure range. Therefore, the operating point of the pump should be selected within this range instead of making the pump work long-term at 25~30mmHg.
7. How the oil vapor discharged from the vacuum pump affects the environment. If the environment does not allow contamination, an oil-free vacuum pump can be selected or the oil vapor can be discharged outdoors.
8. The working pressure of the vacuum pump should meet the ultimate vacuum and working pressure requirements of the vacuum equipment.
9. Vacuum pump price, operation and maintenance costs.