1. Vacuum components, such as valves, air inlet pipe and a vacuum pump connected to each other, as far as possible should be pumping short pipeline, pipe diameter to not less than the main pump entrance diameter, and pipe to minimize the use of elbow especially elbow. This is an important principle for the vacuum system.
2. Vacuum system structure materials should try to use the national standard seamless steel tube and plate, and minimize the number of welds, welding steel is generally 20 steel or Q235-A.F steel (A3 steel). Of particular note is: access pipeline vacuum system should be cleaned, and the thickness of pipe wall access should not be too thin, too thin for the pipeline pumping operation under rough vacuum conditions will produce strong resonance.
3. Operating rules of vacuum system:
A. When the starts the mechanical pump, it is necessary to ensure the correct direction of the rotor movement and the oil level is in line with the requirements.
B. After stopping the oil seal mechanical pump, the mechanical pump inlet is immediately passed through the atmosphere. The pump oil enters the system because of the vacuum in the pump.
C. Try not to pump the high vacuum chamber directly to below 10Pa (0.1Torr) pressure by mechanical pump, otherwise the oil vapor of the mechanical pump will enter the high vacuum chamber. Because when the pressure below 10Pa, there will be molecular air flow, oil molecules will flow back to the vacuum chamber and cause pollution. If the oil must be less than 10Pa, the oil molecular trap should be installed.
D. Should not make the mechanical pump work at atmospheric pressure or under high pressure for a long time, otherwise the motor will overheat, and the pump will spray oil mist.
E. Before the diffusion pump (or oil booster pump) through the atmosphere, the pump oil should be cooled to a safe temperature, to prevent the oxidation of pump oil at high temperature.
F. When uses ionization timing, the ionization vacuum gauge should be restarted when the pressure is below 0.1 Pa to prevent the burnout of the ionization meter.
G. When the high vacuum system needs to be stopped, vacuum chamber and main pump can be sealed in vacuum to shorten the pumping time under the next use.
H. The system of cooling water pressure is generally greater than 1 kg and less than 2.5 kg, low pressure will cause the cooling water circulation, excessive pressure will lead to Water Leakage or pump the water sleeve to be crushed and fault. The 1# oil must be used when adding oil into the pump.