Installing Air/Liquid Heat Exchanger Pipes

Procedure

1. Determine the position of the water pipe ports on the air/liquid heat exchanger.
2. Install water pipes for the air/liquid heat exchanger.

   Connect the water inlet and outlet pipes correctly according to the red and blue labels. The red label indicates water outlet, and the blue label indicates water inlet.

   1. Use a screwdriver to loosen the screws that secure the baffle plate and remove the baffle plate.
      Figure 8-127 Removing the baffle plate
      
   2. Loosen the clamp on the external pipe ports of the air/liquid heat exchanger counterclockwise, and remove the clamp and plug. See (1) and (2) in Figure 8-128.

      The sealing ring needs to be retained on the pipe port.

      Figure 8-128 Removing the clamp and plug
      
   3. Connect the pipe port of the primary loop of the equipment room to that of the air/liquid heat exchanger. See (1) in Figure 8-129.

      Do not move the sealing ring during the connection. Ensure that the round bulge on the sealing ring is aligned with the groove on the hose connector.

   4. Bend the pipe, use a clamp to connect the pipe port of the primary loop and that of the air/liquid heat exchanger, and use a torque wrench to tighten the clamp. See (2) in Figure 8-129.

      The recommended torque value is 9 N·m to 11 N·m.

      Figure 8-129 Install water inlet and outlet pipes.
      

3. Check the air tightness of the connection port between the air/liquid heat exchanger and the primary loop.
   1. Close the ball valve at the branch and ensure that the air/liquid heat exchanger with qualified air tightness is connected to the primary loop.
   2. Use an oil-free air compressor (or a nitrogen cylinder with a reducing valve) to increase the pressure to 600–650 kPa. For details, see Step 2.
   3. Check the air tightness of the connection port between the air/liquid heat exchanger and the primary loop.
      • Soap bubble method
        1. Cut the soap into thin slices and soak them in warm water to melt into thick soapy water so that soap bubbles can be blown out.

           If conditions permit, 5% to 10% glycerol can prolong the time for the bubble at the leak point bubble to appear.

        2. Apply soapy water to the connection port between the air/liquid heat exchanger and the primary loop, and ensure that the port is completely covered by soapy water.
        3. Observe for three to five minutes and check whether bubbles appear at the port.
           • If yes, the air tightness of the connection port is unqualified. Reconnect the air/liquid heat exchanger after releasing the pressure.
           • If no, the connection port is qualified. After the air is discharged and the pressure is released, tighten the exhaust valve and reset the baffle plate.
      • Pressure drop method
        1. Disconnect the oil-free air compressor (or the nitrogen cylinder with a reducing valve). After the pressure is stable for 10 minutes, record the pressure gauge reading.
        2. Preserve the pressure for 60 minutes, and record the data again.
        3. Calculate the pressure drop.
        4. Check whether the pressure drop is less than or equal to 5 kPa.
           • If yes, check and reconnect the connection port between the air/liquid heat exchanger and the primary loop.
           • If no, the connection port is qualified. After the air is discharged and the pressure is released, tighten the exhaust valve and reset the baffle plate.

4. Use a Phillips screwdriver to tighten the captive screws used to secure the baffle plate. See (1) in Figure 8-130. Slide the baffle plate to close it. See (2) in Figure 8-130.
   Figure 8-130 Closing the baffle plate of the exhaust valve
   

5. Shut down the air/liquid heat exchanger.
6. Perform follow-up operations.

   After the installation is complete, clean the equipment room and ensure that the operating environment is tidy:

   • Installation tools are placed in specified locations.
   • Remove the waste to keep the equipment room clean and tidy.
   • Remaining materials are handed over to the customer.