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HVACR316 - Piping

Piping ApplicationsBrazing

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Piping Applications

• One of the most important tasks the installation crew can perform to ensure the long term satisfactory operation of the refrigeration system is the proper installation of the refrigeration lines.

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Piping Applications

• Poorly installed refrigerant lines can result in premature compressor failure, as well as an inefficient system.

• The technician installing these lines should keep a number of things in mind, including:– The run should be as short as possible.– No excessive piping should be used.– The number of fittings should kept to a

minimum.

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Piping Applications

• Technician reminders, cont’d.– When needed, long radius elbows

should be used.– All braze joints should be perfect.– The suction line should be pitched back

toward the compressor.– The suction line should always be

insulated.

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Piping Applications

• Although the preceding list seems to be quite long, following those guidelines will give you a satisfactory piping job. If any one of the items is neglected, system operation will be affected in a negative way.

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Piping Applications

• The indoor and outdoor units should be as close to each other as possible. To ensure maximum efficiency, the piping run should be as direct as possible, with no excessive braze joints or pipe sections.

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Piping Applications

• During the piping process, a number of pipe fittings will need to be installed, such as 90 degree elbows and couplings. When choosing 90 degree elbows, select those with a wide or long radius.

• Wide radius elbows provide less resistance to refrigerant flow than those with tighter radius. This helps maintain constant refrigerant velocity.

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Piping Applications

• Each fitting that is added to the refrigerant piping circuit adds to the resistance encountered by the refrigerant; therefore, the number of fittings should be kept to a minimum.

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Piping Applications

• Reducing the number of fittings will also reduce the number of braze joints required to connect the evaporator unit and condenser unit.

• The smaller the number of braze joints, the smaller the chance of a refrigerant leak occurring.

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Brazing

• The following procedure may be used to set up an oxygen acetylene torch system for use.– With the regulator assembly now fastened

to the tank, the t-handles on the regulators should be turned counterclockwise to assure the regulator is closed and no pressure will go into the hoses on the assembly.

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• Setup for oxyacetylene torch, cont’d.– Turn on the acetylene cylinder valve one-

half turn, so that pressure is introduced to the regulator. You will see the pressure register on the acetylene cylinder gauge.

– Slowly turn on the oxygen cylinder valve to the oxygen regulator. You should see pressure register on the oxygen cylinder pressure gauge.

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• Setup for oxyacetylene torch, cont’d.– Slightly open the valve on the torch handle

that controls the acetylene, (the red hose). With this valve slightly open, adjust the T-handle on the acetylene regulator until the gauge on the red hose reads 5 psig.

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• Setup of oxyacetylene torch, cont’d.– Next, slightly open the valve on the torch

handle that controls the oxygen (the green hose). With the valve slightly open, adjust the T-handle on the oxygen regulator until the gauge reads 10 psig.

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• The following procedure may be used to light the torch for use.– Slightly open the valve on the torch handle

on the acetylene side and allow it to flow a moment to get any air out of the line.

– Using an approved flint style striker, lighting only the acetylene gas; you will have a large yellow-orange flame, which will smoke.

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• Slightly open the valve on the torch handle on the oxygen side; the flame will begin to clear up and turn blue. You will have to adjust the valves until you get the flame that you want. The flame should be blue and be setting firmly on the torch tip, not blowing away from it.

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• To shut down the system, follow these procedures:– Shut off the fuel gas value at the torch first.– Shut off the oxygen valve at the torch.– Turn off the cylinder value for the acetylene

gas.– Open the valve on the torch handle on the

fuel gas side to relieve the pressure on the hose. Both regulators will lose their pressure to 0 psig.

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Brazing

• To shut down the system, cont’d.– Turn the T-handle on the fuel gas regulator

counterclockwise until it appears to be loose. This side of the system has now been bled of pressure. Shut off the valve to the torch handle.

– Turn off the cylinder valve on the oxygen cylinder.

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Brazing• To shut down the system, cont’d.

– Open the value on the torch handle on the oxygen side to relieve the pressure on the hose. Both regulators will lose their pressure to 0 psig. This side of the system has been bled of pressure. Turn off the torch handle valve on the torch handle.

– Turn the T-handle on the oxygen regulator counterclockwise until it feels loose.

– The system is now ready for storage.