Test Operation ESIE09-0874 Test Operation1.2 Air Tight Test and Vacuum Drying Air tight test: Make sure to use nitrogen gas. Do this before powering the unit. Setup:The leak test must satisfy specification EN 378-2.1. Vacuum leak test Evacuate the system from the liquid and gas piping to –100.7 kPa (5 Torr). Once reached, turn off the vacuum pump and check that the pressure does not risefor at least 1 minute. Should the pressure rise, the system may either contain moisture (see vacuum dryingbelow) or have leaks.2. Pressure leak test Break the vacuum by pressurizing with nitrogen gas to a minimum gauge pressure of0.2 MPa (2 bar).Never set the gauge pressure higher than the maximum operation pressure of theunit, i.e. 4.0 MPa (40 bar). Test for leaks by applying a bubble test solution to all piping connections.Make sure to use a recommended bubble test solution from your wholesaler.Do not use soap water, which may cause cracking of flare nuts (soap water maycontain salt, which absorbs moisture that will freeze when the piping gets cold), and/or lead to corrosion of flared joints (soap water may contain ammonia which causes acorrosive effect between the brass flare nut and the copper flare).3. Discharge all nitrogen gas. Pressurize the liquid and gas pipes to 4.0 MPa (40 bar) (do not pressurize more than 4.0MPa (40 bar)). If the pressure does not drop within 24 hours, the system passes the test. Ifthe pressure drops, check where the nitrogen leaks from. Vacuum drying: Use a vacuum pump which can evacuate to –100.7 kPa (5 Torr, –755 mmHg). Connect the vacuum pump to both service port of the gas stop valve and the liquid stopvalve to increase efficiency.1. Evacuate the system from the liquid and gas pipes by using a vacuum pump for morethan 2 hours and bring the system to –100.7 kPa. After keeping the system under thatcondition for more than 1 hour, check if the vacuum gauge rises or not. If it rises, thesystem may either contain moisture inside or have leaks.2. Following should be executed if there is a possibility of moisture remaining inside thepipe (if piping work is carried out during the raining season or over a long period of time,rainwater may enter the pipe during work).1 Pressure reducing valve2 Nitrogen3 Siphon system4 Vacuum pomp5 Valve A6 Gas line stop valve7 Liquid line stop valve8 Stop valve service port9 Charge hose12 4 9 R-410A6783 5
