-
27
-
'11 • KX-T-166
For operation valves both at the fluid and gas sides, fix the valve body and tighten to adequate torque as shown at right.
Operation valve size
(mm)
Tightening angle
(° )
Tightening torque
(N
・
m)
Recommended length of tool handle
(mm)
ø
6.35
（
1/4"
）
14
〜
18
45
〜
60
150
ø
9.52
（
3/8"
）
34
〜
42
30
〜
45
200
ø
12.7
（
1/2"
）
49
〜
61
30
〜
45
250
ø
15.8 8
（
5/8"
）
68
〜
82
15
〜
20
300
ø
19.05 (3/4"
）
100
〜
120
15
〜
20
450
4-3. Air tightness test and air purge
(1) Air tightness test
Use a torque wrench. If a torque wrench is not available,
fasten the flare nut manually first and then tighten it
further, using the left table as a guide.
Do not hold the valve cap area with a spanner.
●
Do not apply any oil on a flare joint.
●
Blazing must be performed under a nitrogen gas flow
. Without nitrogen gas, a large quantity of foreign matters (oxidized film) are created, causing a critical failure
from capillary tube or expansion valve clogging.
●
Brazing of the service valve and the pipes should be performed while cooling the valve body with a wet towel.
●
Perform flushing. To flush the piping, charge nitrogen gas at about 0.02MPa with a pipe end closed with a hand. When pressure inside builds up to a sufficient level,
remove the hand to flush. (in flushing a pipe, close the other end of the pipe with a plug).
Plug the end of the pipe with tape, or other
material, and fill the pipe with nitrogen gas.
Only use nitrogen gas (N
２
)
Taping
＜
N
２
＞
Nitrogen
Brazing
Brazing
Flatten
Adhesive tape
Station valve
0.02MPa
Hand
Relief valve
Nitrogen
gas
Operation procedure
①
During the pipe installation at site, keep the service valves shut all the time
.
②
Blazing must be performed under a nitrogen gas flow
. Without nitrogen gas, a large
quantity of foreign matters (oxidized film) are created, causing a critical failure from capillary
tube or expansion valve clogging.
③
Give
sufficient protections
(compressed and brazed or with an adhesive tape)
so that water or foreign matters may not enter the piping
.
④
Perform flushing. To flush the piping, charge nitrogen gas at about 0.02MPa with a pipe end
closed with a hand. When pressure inside builds up to a sufficient level, remove the hand to
flush. (in flushing a pipe, close the other end of the pipe with a plug).
①
Although an outdoor unit itself has been tested for air tightness at the factory, please check the connected pipes and indoor units for air tightness from the check joint of
the service valve on the outdoor unit side. While conducting a test,
keep the service valve shut all the time
.
②
Since refrigerant piping is pressurized to the design pressure of a unit with nitrogen gas for testing air tightness, please connect instruments according the drawing below.
Under no circumstances should chlorine-based refrigerant, oxygen or any other combustible gas be used to pressurize a system
Keep the service valve shut all the time
. Do not open it under any circumstances.
Be sure to pressurize all of the liquid, gas pipes
.
③
In pressurizing the piping, do not apply the specified level of pressure all at once, but gradually raise pressure.
a)
Raise the pressure to 0.5 MPa, and then stop. Leave it for five minutes or more
to see if the pressure drops.
b)
Then raise the pressure to 1.5 MPa, and stop. Leave it for five more minutes
to see if the pressure drops.
c) Then raise the pressure to the specified level (3.24 MPa), and record the ambient temperature and the pressure.
d)
If no pressure drop is observed with an installation pressurized to
the specified level
and left for about one day
,
it is acceptable
. When the ambient temperature
changes 1
℃
, the pressure also changes approximately 0.01 MPa. The pressure, if changed, should be compensated for.
e) If a pressure drop is observed in checking e) and a) – d), a leak exists somewhere. Find a leak by applying bubble test liquid to welded parts and flare joints and repair
it. After repair, conduct an air-tightness test again.
④
Always pull air from the pipes after the airtightness test.
CAUTION
Applying excessive pressure can cause an
inflow of nitrogen gas into an outdoor unit.
Primary side
Secondary side
Securely tighten the cap and the blind nut after the adjustment.
Avoid applying any excessive force when operating the shaft or when
tightening the cap or blind nut. Otherwise, it could cause malfunction or
leakage from the shaft, cap or blind nut.
Operation valve size
(mm)
Cap tightening torque
(N·m)
Shaft tightening torque
(N·m)
Check joint blind nut
tightening torque
(N·m)
ø
9.52 (3/8")
6~8
20~30
10~12
ø
12.7 (1/2")
14~16
25~35
10~12
ø
19.05 (3/4")
3
30~35
12~14
Standard torque at sections on operation valve
・
Open the valve stem till it hits the stopper. No need to apply
force more than that.
・
After the adjustment, replace the blind nut as it was.
・
After the adjustment, replace the cap as it
was.
Remove the cap and adjust as shown below
State at shipping (closed)
State of open
Pin type
Stopper
Pin
To indoor unit
Gauge manifold
Lo
Lo knob
Hi
Hi knob
Service point
(check joint)
Operation valve
Liquid pipe
Gas pipe
Outdoor unit
Allen wrench
(M4)
Fluid/gas operation valve
Open
Allen wrench type
Nitrogen
gas
▲
▲
