Evacuation System
When the system has been checked for refrigerant leakage must be corrected using EPA approved procedures. After the source of the leak repair, you must evacuate the system to remove all residual air and moisture from the system. Most change/return the units include a built-in vacuum pump. To ensure that all moisture has been removed from the system, digital vacuum gauge is used. Digital sensor vacuum is more accurate than the manifold. This gives the opportunity to discover the perfect vacuum up to 30 kPa (760 mm Hg, 760,000 microns). Connect the manifold. Open both the unloading valve, and the intake valve. Then vacuum pump on the whole system. Remove air will be discharged via a vacuum pump.
In 3ft3/min (0.085 m /min) vacuum pump is large enough for networks up to 10 PS (7.46 kW). Pressure drop is very important! Service lines should be as large and as short as possible. Evacuation takes eight times longer with 1/4" (6.35 mm) line than 1/2" (12,7 mm) line. It will take twice as long and 6' (1.83 m) line, but after 3' (0.91 m) line.
Use heat lamps, electric heaters and blowers to provide heat. Avoid using a torch flame. This may cause local high temperatures, which can decompose oil, insulation, and refrigerant. When the pump is shut off (valve closed), the pressure will rise slightly due to pressure drop alignment. Take a reading one minute after the closing of the valve and another 30 minutes later. If not, increase the pressure, the sealing system and free of moisture...
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Industrial