Haier 2U18MS2VHB Installation Manual - page 8
INSTALLATION
PAGE 8
ENGLISH
Leak Test
3.1
Step - 3.1
Refrigerant piping connections for the mini-split system are
made utilizing flare connections. Follow standard practices
for creating pipe flares. When cutting and reaming the tubing,
use caution to prevent dirt or debris from entering the tubing.
Remember to place the nut on the pipe before creating the
flare.
3.2
Step - 3.2
To join the lineset piping together, directly align the piping
flare to the fitting on the other pipe, then slide the nut onto
the fitting and tighten. Misalignment may result in a leaking
connection.
3.3
Step - 3.3
Two wrenches are required to join the flare connections, one
standard wrench, and one torque wrench. See Table 1 for the
specific torque per piping diameter.
Step 3.1
Half union
Flare nut
Torque wrench
Spanner
Forced fastening without careful centering may
damage the threads and cause a leakage of gas.
Pipe Diameter(ǿ)
Fastening torque
Liquid side6.35mm(1/4")
18N.m/13.3Ft.lbs
Liquid/Gas side9.52mm(3/8") 42 N.m/30.1Ft.lbs
Gas side 12.7mm(1/2")
55N.m/40.6Ft.lbs
Gas side 15.88mm(5/8")
60 N.m/44.3Ft.lbs
Table 1
Step 3.2
Step 3.3
Hazard of Explosion! Never use an open flame to detect
gas leaks. Explosive conditions may occur. Use a leak test
solution or other approved methods for leak testing. Failure
to follow recommended safe leak test procedures could
result In death or serious injury or equipment or property
damage.
Use only dry nitrogen with a pressure regulator for
pressurizing unit. Do not use acetylene, oxygen or
compressed air or mixtures containing them for pressure
testing. Do not use mixtures of a hydrogen containing
refrigerant and air above atmospheric pressure for pressure
testing as they may become flammable and could result in
an explosion. Refrigerant, when used as a trace gas should
only be mixed with dry nitrogen for pressurizing units. Failure
to follow these recommendations could result in death or
serious injury or equipment or property damage.
Step 4.1
Piping Connection
Step 3 - Refrigerant Line Connections
Step 4 - Leak Test and Evacuation
4.1
Step - 4.1
Using a tank of nitrogen with attached regulator, charge
the system with 150 PSIG of dry nitrogen. Use adapter AD-
87 (field supplied) to connect to the valve. Check for leaks
at the flare fittings using soap bubbles or other detection
methods. If a leak is detected, repair and recheck. If no leaks
are detected, proceed to evacuate the system.