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Daikin R-410A Installation Manual: Stop Valve Operation Procedure

Edus 39-605a-n.
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EDUS39-605
6-4 Leak test and vacuum drying
Ensure units were checked for leaks by the manufactur-
erand confirm that the valves are firmly closed before
pressure test or vacuuming.
To prevent entry of any impurities and to ensure sufficient
pressure resistance, always use the special specific tools for
R-410A.
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 at right.
[Service precautions]
1.
Label location
Electric box lid
2.
[Caution]
3.
Label location
Pressurize the liquid and gas pipes to
551 psi. Do not pressurize more than 551 psi. If the pres-
sure 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 that can evacuate to
–14.6 psi.
Evacuate the system from the liquid and gas pipes by
1.
using a vacuum pump for more than 2 hours and bring
the system to –14.6 psi. 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 con-
tain moisture inside or have leaks.
If piping work is carried out during the raining season or
2.
over a long period of time, rainwater may enter the pipe
during work. Take the following steps if there is a possi-
bility of moisture remaining inside the pipe: After evacu-
ating the system for 2 hours, pressurize the system to
7.25psi (vacuum break) with nitrogen gas and evacuate
the system again using the vacuum pump for 1 hour to –
14.6 psi (vacuum drying). If the system cannot be evac-
uated to –14.6 psi within 2 hours, repeat the operation of
vacuum 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 stop valve shown in the
table on the below
.
One outdoor unit installed:
Multiple outdoor units installed:

Stop valve operation procedure

Introduction
Confirm the sizes of the stop valves connected to the system
referring to the table on the below.
Q72 type
φ 3/8"
Liquid line stop valve
φ 7/8"
Gas line stop valve
Installation of Outdoor Units
1
3
Liquid line stop valve
Gas line stop valve
Liquid line stop valve
Gas line stop valve
Oil-equalizing line stop valve
Q96 type
φ 3/8"
φ 7/8"
Opening the stop valve:
1. Remove the cap and turn the valve counterclockwise with
the hexagon wrench.
2. Turn it until the shaft stops.
Do not apply excessive force to the stop 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 stop valve
1. Remove the cap and turn the valve clockwise with the
hexagon wrench.
2
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 below.
Tightening torque
Tightening torque ft.-Ibf (Turn clockwise to close)
Stop
valve
Shaft (valve body)
size
Hexagonal
1/4"
3.98-4.87
3/8"
Hexagonal
7/8"
19.91-24.34
(Refer to figure 24.)
Service port
1.
Cap
2.
Hexagon hole
3.
Shaft
4.
Seal
5.
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
combination. 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 ether oil or ester oil and hand-
tighten the nut 3 to 4 turns as the
initial tightening.
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 ester oil or ether oil.
See the following table for tightening torque.
Applying too much torque may cause the flares to crack.
Cap
Service
Flare nut
(valve lid)
port
10.3-12.5
wrench
9.96-12.17
24.1-29.4
4mm
8.48-10.25
wrench
26.55-32.45
10mm
Torque wrench
Spanner
Piping union
Flare nut
Installation
Gas line
piping
attached
to unit (1)
_
16.23-
_
20.65
28

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