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Building to Suit: Custom Solutions for Construction Equipment
One of the top construction equipment manufacturers worldwide, with a plant in the Southeastern United States, came to us several years ago looking to improve its pre-evacuation and refrigerant charging process.
The goal was increased equipment reliability and shorter process time. Taking into account the ever-present budget constraints, we recommended a VTech 101 Automatic Evacuation and Refrigerant Charging System. The 100 Series offers a wide variety of options with a charging speed of 1.5 oz/second.
Charging time is seldom the bottleneck, however, evacuation is. To perform a thorough evacuation the system had to be pumped to 1 x 10-2 mbar or better during a period of at least 15 minutes for proper out-gassing of the circuit. VTech’s double side evacuation pumping helped to achieve this goal. Lastly, a vacuum decay test had to be performed as an additional leak-test and quality measure.
An additional requirement was a 24 ft filler hose to reach from the machine to the large earthmover! The length of the filler hose affects cycle time and refrigerant charge accuracy as well. We were able to work around this effectively by calibrating each charge size independently and storing them in the PLC memory. All the operator had to do was to recall the model number and the machine would automatically select the proper working cycle (recipe).
The refrigerant supply was set up with a transfer pump, which drew the gas from a 100 lb. tank into a 5 gallon accumulator. The accumulator keeps liquid refrigerant available and softens pressure oscillations from the transfer pump.
This first job resulted in a long-term relationship with the customer leading to additional equipment installations.
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