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6.2 Pipe-work connection
Sweat connection:
•
Locate the suction & liquid pipe service valves in the compressor compartment by removing the service access
panel
•
Check that the service valves are tightly closed (Service Ball valves have been provided for suction and liquid
lines)
•
Wrap each valve in turn with a wet cloth prior to sweating off its associated blanking plate (Flare nut connection is
fitted on some of the indoor units to avoid brazing)
•
Braze the interconnecting liquid and suction pipes from the indoor unit
•
Pressurise the indoor unit & pipe-work again with dry nitrogen and check for any brazed joint leaks. Repair as
necessary but ensure the system is not under pressure prior to brazing
•
With the indoor unit pressure again released, evacuate to a vacuum pressure of 100 microns minimum
•
Disconnect the vacuum pump whilst retaining the system vacuum
•
Open the liquid line valve fully first, and then the suction line valve
Flare connection:
•
Cut the pipe with pipe cutter
•
Insert the flare nut into the pipe and flare the end
•
Refer to the following table for the dimension of flare nut spaces:
Table 3 – Flare Dimensions and Flare Tightening Torque
•
Connect the indoor unit first and then the outdoor unit.
•
Bend the refrigerant pipe in the correct way to prevent damage.
•
The bending angle should not exceed 90°.
•
The preference is to place any b ends in the middle of the pipe. The larger the bending radius the better, as it reduces internal
pressure drop.
•
Do not bend pipe more than is necessary.
•
When connecting the flare nut, coat the flare both inside and outs ide with approved oil and initially tighten by
hand 3 or 4 turns before tightening firmly.
