Air-Tight Test - Hitachi RAS-8FSXN1E Manuel D'utilisation

PIPING WORK AND REFRIGERANT CHARGE
8.2 REFRIGERANT CHARGE

8.2.1 Air-Tight Test

Check to ensure that spindles of the stop valves for High/Low
pressure gas, Low pressure gas and Liquid pipes are closed
completely before air-tight test.
The refrigerant used for this outdoor unit is R410A only. Use
the manifold gauge and the charging hose for exclusive use of
R410A.
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Tightening check of stop valves
After connecting the pipe, remove the caps of stop valves for
high/low pressure gas, low pressure gas (for heat recovery
system only) and liquid. Tighten the open-close spindle in the
closing direction according to the following tightening torque.
Caution for operation of stop valves
a. Remove the stop valve caps before performing the air-
tight test after connecting the refrigerant piping. Tighten
the spindle (valve) in clockwise direction according to the
following tightening torque.
b. Perform the work after warming the spindle part with
a dryer etc. when controlling the stop valve in a cold
area. (O-ring of the spindle part will harden at the low
temperature and the refrigerant leakage may occur.)
c. Do not apply an excessive force after fully opening the
spindle. (Tightening Torque: < 5.0N.m) (The back seat is
not provided.)
d. When each valve is opened, remove tags "Close"
(Accessories) and attach tags "Open" instead.
e. Tighten securely the caps according to the following
tightening torque after each spindle valve is opened.
Stop valve for low
pressure gas
Stop valve
for liquid
22 PMML0392B rev.1 - 07/2016
Stop valve for high/low
pressure gas
Flare nut
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Air-tight test method
Connect the manifold gauge to the check joints of the liquid
line and the gas line stop valves using charging hoses with a
vacuum pump or a nitrogen cylinder. Perform the air-tight test.
Do not open the stop valves. Apply nitrogen gas pressure of
4.15MPa for FSXN1E and FSXNHE series. For checking gas
leakage, use the leak detector or forming agent. If there is any
leakage, fix the leaking part.
For checking gas leakage, do not use a forming agent which
generates ammonia. Additionally, do NOT use a household
detergent as forming agent whose components are not clear.
The recommended foaming agent for checking gas leakage is
shown below.
Procedure
Completion
Applying
of refrigerant
nitrogen gas
piping
Recommended forming agent
Guproflex
!
D A N G E R
Be sure to use Nitrogen Gas for air-tight test. If other gases such
as oxygen gas, acetylene gas or fluorocarbon gas are accidentally
used, it may cause an explosion or gas intoxication.
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Insulation work
1 Securely insulate high/low pressure and low pressure (for
heat recovery system only) gas piping side and liquid piping
side individually. Make sure to insulate the union flare nut for
the piping connection as well.
2 Mount the piping cover equipped with the outdoor unit after
connecting the pipe. Completely seal the penetration part
at the bottom of the pipes with insulation in order to prevent
rain water from entering the conduit.
3 Cover the gap between the piping cover and pipes with
a packing (field-supplied) after the insulation work is
completed.
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N O T E
If the gap is not covered, the unit may be damaged if snow, rain water or
animals enter the unit.
Check of pressure
decrease
Repairing of
leakage part
Manufacturer
Yokogawa & CO.,Ltd
Pass