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            Leak 
              Test Application from TQC 
            High 
              Speed Leak Testing of Welded Pipe Fittings 
            Systems 
              using Air & Helium as Test Mediums 
            
            TQC have supplied a suite of 3 automatic leak testing 
              machines that are conveyor fed.  
            The first two machines were designed to 100% leak 
              test numerous variants of welded metal T-pieces, elbows, reducers 
              and adapters used in the water, gas and construction industries. 
              The leak test specification meant that the parts needed to be water 
              tight.  
            The customer then asked TQC to develop a machine to 
              meet the more stringent requirements of testing parts to ensure 
              they are gas tight, and still meet the high production throughputs. 
              TQC met these objectives by integrating helium leak testing technology 
              into the same handling concept of the first two machines.  
            The main 
              features of each leak test machine are : 
            
              -  Rotary indexing machine
 
              - Automated load / unload
 
              - Twin chamber with interchangable tooling for multiple variants
 
              - Combination leak test using high pressure internally and high 
                vacuum externally 
 
              - High speed leak test
 
              - Water and Gas tight leak specification met using air or helium 
                as test medium
 
              - Testing to leak test threshold of 1mm3/sec (1x10-6 mbar.l.sec-1)
 
             
            Handling 
              System 
                
            A twin gripper pick and place system was used to load 
              parts from a conveyor pallet to the test fixture and then remove 
              the parts after testing. Twin chamber test fixtures mounted on a 
              rotating table were used to allow automated load and unload whilst 
              meeting the high throughput.  
            Air 
              Test Medium   
            Leak test instruments tested each component. Both 
              internal high pressure and external vacuum was used to stress the 
              part under test correctly and to provide a short cycle time leak 
              test 
            
               
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                | Leak 
                  Test Machine  | 
                Close 
                  up of tooling, leak test chambers etc. | 
               
             
            Helium 
              Test Medium  
            The test process required the part to be evacuated, 
              low pressure helium inserted for a gross leak test, then high pressure 
              helium for a fine leak. On completion, the helium was removed from 
              the part and the part stabilised with air. 
             The system included monitoring of any leaking helium 
              this allows fast testing and minimises helium loss by part leakage. 
             
            Varian mass spectrometers have been integrated to 
              monitor the helium gas, with a trigger point used to indicate a 
              leaking part. The leak test threshold that was set by the customer 
              was 1mm3/sec (1 x 10-6 mbar.l.sec-1).  
            A helium reuse system was integrated into the test 
              machine, this automatically monitored the gas quality and purged 
              the system once the helium was below a set concentration. By including 
              the recovery system typically 50 -100 parts (depending on internal 
              volume) can be tested before the helium needs to be replaced.  
            
               
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                | Helium 
                  Leak Test Machine | 
                Mass 
                  Spectrometer | 
               
             
            If you are currently considering a high speed 
              or complex leak test application, or production automation call 
              us and we will be happy to offer our professional advice & visit 
              you at your site. 
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