Connections To The External Unit; Creating A Vacuum And Checking The Seal - Ariston NEVIS PROtech Serie Manuel D'utilisation Et D'entretien

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4. Connect the pipes using two spanners, taking care not to damage the pip-
ing. 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 connections".
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 tight-
ness 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 dy-
namometric 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 mod-
el. When the length is over 5 m, take care to add the right amount of refriger-
ant per metre.
If you need to install the external and internal units with a height diff erence
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 detector
(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 :
1. unscrew the caps on the cocks of the two-way and three-way valves, and on
the service valve;
2. connect the vacuum pump to the small service valve in the external unit
three-way valve;
44 /
Corresponding eff ort
(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 (20) m
GAS COCK
5 m