The vacuum pump should be used to remove steam and moisture from the system. The most common type is called two-stage rotary vacuum pump. Cm. Fig. 12-93. It consists of two chambers and gets a deep vacuum. This type of pump can reduce the pressure to the extremely low level of 0.01 microns. However, it is rarely used at these levels in the region. Featured manufacturer of vacuum 250 microns, 50 mm, depending on the type of system.
The removal of moisture from the system by reducing the pressure. Any moisture will boil (evaporate) and be removed using gas. System opened for any type of repair should be entirely excluded. It is necessary to remove air and moisture.
Two different evacuation methods are used;
Deep vacuum.
Triple evacuation.
In the first method, vacuum 500 microns (0.5 mm) or deep pumped until no moisture or other gas remains in the system.
Techniques often uses a thermistor vacuum gauge vacuum pump to create a vacuum. This indicator shows when the system is free from memory leaks, moisture-free and ready to be recharged.
This sensor is often used as controller of leakage in the system.. vacuum gauge sensor is often installed as part of the pump vacuum collector line. This is easily done with the help of the T-fit ting.
In the second triple evacuation) method:
Vacuum 28" Hg (49 mm) - a draw,
System charged with psig 0 (14.7 psi 103 kPa) with refrigerant vapor.
Vacuum 28" Hg is drawn again.
System charged with psig 0 refrigerant vapor.
Vacuum 28" Hg drawn.
The system is ready for charging.
R-22 has a higher level, pressure and temperature, than of R-12. Mud, silt, moisture and air should be removed from the system. This prevents possible burnouts, where R-22 is used. Full (high) evacuation is one of the best ways to clean the system...
Industrial