Mitsubishi Heavy Industries FDC112KXEN6 Technical Manual page 250

Fix both liquid and gas service valves at the valve main bodies as illustrated on the right, and then fasten them, applying
appropriate fastening torque.
ervice valve size Tightening torque
(mm) (N-m)
¿6.35 (1/4") 14 ~ 18
¿9.52 (3/8") 34 ~ 42
¿12.7 (1/2") 49 ~ 61
¿15.88(5/8") 68 ~ 82
● 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).
Operation procedure
q During the pipe installation at site, keep the service valves shut all the time.
w 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.
e Give sufficient protections (compressed and brazed or with an adhesive tape) so that water or foreign matters
may not enter the piping.
r 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).
Tightening angle Recommended length
of a tool handle (mm)
(¡ )
45 ~ 60 150
30 ~ 45 200
30 ~ 45 250
15 ~ 20 300
material, and fill the pipe with nitrogen gas.
Taping
Only use nitrogen gas (N
Nitrogen
Flatten
razing
Primary side econdary side
tation valve
Nitrogen Relief valve
gas
246
-
Do not hold the valve cap area
with a spanner.
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.
lug the end of the pipe with tape, or other
N
2
)
2
Brazing
0.02MPa
Hand
-
Adhesive tape