Leak Test And Vacuum Drying - Daikin VRV II RX5MY1 Installation Manual

6-4 Leak test and vacuum drying

The units were checked for leaks by the manufacturer.
Confirm that the valves are firmly closed before pressure test or vac-
uuming.
To prevent entry of any impurities and insure sufficient pressure
resistance, always use the special tools dedicated for R22.
Air tight test and vacuum drying
• Air tight test: Make sure to use nitrogen gas.
(For the service port location, refer to the
"Caution" label attached on the front panel
[right] of the outdoor unit.)
(Refer to figure)
1. [Service precautions]
Label location
2. Electric box lid
3. [Caution]
Label location
Pressurize the liquid and gas pipes to
2.8MPa (28bar) (do not pressurize more
than 2.8MPa (28bar)). If the pressure does not drop within 24
hours, the system passes the test. If the pressure drops, check
where the nitrogen leaks from.
• Vacuum drying: Use a vacuum pump which can evacuate to
–100.7kPa (5Torr, –755mmHg).
1. Evacuate the system from the liquid and gas pipes by using a
vacuum pump for more than 2 hours and bring the system to
–100.7kPa. After keeping the system under that condition for
more than 1 hour, check if the vacuum gauge rises or not. If it
rises, the system may either contain moisture inside or have
leaks.
2. Following should be executed if there is a possibility of mois-
ture remaining inside the pipe (if piping work is carried out dur-
ing the raining season or over a long period of time rainwater
may enter the pipe during work).
After evacuating the system for 2 hours, pressurize the system
to 0.05MPa (vacuum break) with nitrogen gas and evacuate
the system again using the vacuum pump for 1 hour to
–100.7kPa (vacuum drying). If the system cannot be evacu-
ated to –100.7kPa within 2 hours, repeat the operation of vac-
uum break and vacuum drying.
Then, after leaving the system in vacuum for 1 hour, confirm
that the vacuum gauge does not rise.
Note
Make sure to perform airtightness test and vacuum drying using the
service ports of the shutoff valve shown in the table on the bellow.
One outdoor unit installed: In
case of
RX5-16 type
When multiple outdoor units
installed: In case of
RX18-48 type
Shutoff valve operation procedure
Introduction
Confirm the sizes of the shutoff valves connected to the system refer-
ring to the table on the below.
RX5 RX8
type type
φ 9.5
(The model RX8·10 supports
Liquid line
onsite piping of φ12.7 by the
shutoff valve
accessory pipes)
φ 15.9 φ 22.2
(The model (The model RX8· 10
RX5 sup- supports onsite piping
of φ28.6 by the
Gas line ports onsite
shutoff valve piping of accessory pipes)
φ19.1 by the
accessory
pipes)
Opening shutoff valve
1.
Remove the cap and turn the valve counterclockwise with the
hexagon wrench (JISB4648).
2.
Turn it until the shaft stops.
English
1
3
Liquid line shutoff valve
Gas line shutoff valve
Liquid line shutoff valve
Gas line shutoff valve
Oil-equalizing line shutoff valve
RX10 RX12 RX14 RX16
type type type type
φ 12.7
(The model RX12·14·16
supports onsite piping of
φ15.9 by the accessory
pipes)
φ 25.4
(The model RX12·14·16
supports onsite piping of
φ34.9 by the accessory pipes)
Do not apply excessive force to the shutoff valve. Doing so may
break the valve body, as the valve is not a backseat type. Always
use the special tool.
3.
Make sure to tighten the cap securely.
Closing shutoff valve
1.
Remove the cap and turn the valve clockwise with the hexagon
wrench (JISB4648).
2.
Securely tighten the valve until the shaft contacts the main body
seal.
3.
Make sure to tighten the cap securely.
∗ For the tightening torque, refer to the table on the bellow.
2
Tightening torque
Tightening torque N-m (Turn clockwise to close)
Shutoff
valve
Shaft (valve body)
size
φ6.4
Hexagonal
5.4-6.6
φ9.5
wrench
4 mm
φ12.7
8.1-9.9
Hexagonal
φ15.9
13.5-16.5 wrench
6 mm
φ22.2
Hexagonal
27-33 wrench
φ25.4
10 mm
(Refer to figure 26)
1. Service port
2. Cap
3. Hexagon hole
4. Shaft
5. Seal
〈 〈 〈 〈 Caution〉 〉 〉 〉
• Always use a charge hose for service port connection.
• After tightening the cap, check that no refrigerant leaks are
present.
• When loosening a flare nut, always use two wrenches in combi-
nation. When connecting the piping, always use a spanner and
torque wrench in combination to tighten the flare nut.
• When connecting a flare nut, coat
the flare (inner and outer faces) with
refrigerant oil and hand-tighten the
nut 3 to 4 turns as the initial tighten-
ing.
FLARE SHAPE and FLARENUT TIGHTENING TORQUE
〈 〈 〈 〈 Precautions when connecting pipes
• See the following table for flare part machining dimensions.
• When connecting the flare nuts, apply refrigerant oil to the inside
and outside of the flares and turn them three or four times at first.
(Use refrigerant oil.)
• See the following table for tightening torque.
(Applying too much torque may cause the flares to crack.)
• After all the piping has been connected, use nitrogen to perform a
gas leak check.
tightening
pipe size
torque (Ncm)
φ
3270 - 3990
9.5
φ
12.7 4950 - 6030
φ
6180 - 7540
15.9
Gas line
Cap Service piping
Flare nut
(valve lid) port attached
to unit (1)
14-17
13.5-16.5
33-39
18-22 50-60
11.5-13.9
23-27 62-75
36-44 _ 22-28
Torque wrench
Spanner
Piping union
Flare nut
〉 〉 〉 〉
A (mm) flare shape
12.8 - 13.2
90 ±2
A
16.2 - 16.6
R=0.4~0.8
19.3 - 19.7
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