12 things to avoid using diffusion pump

Diffusion pump is one of the main tools to obtain high vacuum. They are easy to operate, have no moving parts, are relatively cheap, and have little and easy maintenance.

But even so, there are some points to pay attention to when using diffusion pump. Here are 12 things that vacuum furnace users should avoid when using diffusion pumps.

1. Do not use alternative pump oil.

2. If the diffusion pump is in vacuum, do not stop the cooling water or open the oil filling plug (especially when its temperature is very high).

3. In case of leakage or continuous gas production in the vacuum furnace system, the pressure is 2 μ MHG higher than that near the air inlet of the pump. Do not keep the inlet valve open.

4. Do not use heaters higher than the recommended rating.

5. Do not operate the diffusion pump when the oil level is low.

6. The thermostat usually provides protection for the pump in case of lack of pump oil or water shortage, but the control circuit may fail. Therefore, do not operate the diffusion pump if there is no cooling water circulation or proper front stage pump. For large equipment, double protection is recommended.

7. Do not remove the safety protection device.

8. When the temperature of diffusion pump is very high, do not let air into the pump.

9. Do not turn on the power supply of the diffusion pump unless there is a certain amount of oil in the diffusion pump and the gas is drained to a pressure below 0.5 μ MHG.

10. Do not use steam, powder or material that may react with the recommended pump oil to avoid contamination of the pump.

11. If the diffusion pump fails, do not use the quick cooling water pipe, otherwise harmful condensed water will accumulate at the end of the heater.

12. When the diffusion pump stops running and is exposed to the atmosphere, drain the cooling water of the diffusion pump completely, otherwise it will cause water condensation in the pump.