Connections To The External Unit; Creating A Vacuum And Checking The Seal - Ariston ALYS 25 MC8 User And Installation Manual

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4. Connect the pipes using two spanners, taking care not to damage the
piping. If the tightening force is insuffi cient, then there may well be
leaks. And if the tightening force is excessive, then there may also be
leaks as the fl ange could be damaged. The safest system is constructed
by tightening the connection using a fi xed spanner and a dynamometric
spanner: in this case, use the table "tightening torques for fl ange con-
nections".
5. We recommend you leave an extra 50 cm of pipe for any subsequent
work carried out in the vicinity of the cocks.

2.8 Connections to the external unit

Screw the pipe unions onto the external unit connections with the same
tightness as for the internal unit.
To avoid leaks, pay particular attention to the following points:
- Tighten the pipe unions, taking care not to damage the piping.
- If the tightening force is insuffi cient, then there may well be leaks. And
if the tightening force is excessive, then there may also be leaks as the
fl ange could be damaged.
- The safest system is constructed by tightening the connection using a
dynamometric spanner: in this case, use the tables below (for copper
piping).
TIGHTENING TORQUES FOR FLANGE CONNECTIONS
Pipe Tightening torque
[kgf x cm]
6.35 mm (1/4") 160 - 200
9.52 mm (3/8") 300 - 350
12.70 mm (1/2") 500 - 550
15.88 mm (5/8") 630 - 770
TIGHTENING TORQUE FOR PROTECTION CAPS
Service connection
Protection caps
LENGTH OF THE PIPING
The maximum length for the connection piping varies depending on the
model. When the length is over 5 m, take care to add the right amount of
refrigerant per metre.
If you need to install the external and internal units with a height difference
over 5 m (fi g. B and fi g. C), use siphons on the gas piping in order to allow
oil to return to the compressor properly.
NOTE:
We recommend making a loop in the piping near the external unit, so as to
reduce the vibrations transmitted from that point.
IMPORTANT: CHECK FOR REFRIGERANT LEAKS
Once you have created the connections and a vacuum, open the cocks so
that the gas fi lls the piping and always check for leaks using a leak detec-
tor (risk of personal injury from cold burns).

2.9 Creating a vacuum and checking the seal

A vacuum pump suitable for use with R410A must be used to bleed the
circuit.
Make sure the vacuum pump is fi lled with oil to the level indicated by the
oil indicator light, and that the two cocks on the external unit are shut off:
42
Corresponding effort
(using a 20 cm spanner)
wrist force
arm force
arm force
arm force
Tightening torque [kgf x cm]
70-90
250-300
CONNECTION PIPING
PIPE UNIONS
LIQUID COCK
fi g. B
max 8 (10) m
fi g. C
max 8 (10) m
GAS COCK
5 m
5 m