American Standard 4A7A5 Installer's Manual page 3

4
GAS LINE BALL SERVICE VALVE
CAP
UNIT SIDE
OF VALVE
PRESSURE TAP PORT
5
GAS LINE SERVICE VALVE
BRASS GAS LINE BALL SERVICE VALVE
The Brass Gas Line Ball Service Valve is shipped in the closed
position to hold the factory refrigerant charge. The pressure tap
service port (when depressed) opens only to the field brazing side
when the valve is in the closed position.
The Gas Line Service Valve is full open with a 1/4 turn. See
Figure 4.
BRAZING REFRIGERANT LINES
1. Remove lower access cover to access service valves.
2. Before brazing, remove plugs from external copper stub
tubes. Clean internal and external surfaces of stub tubes prior
to brazing.
3. Cut and fit tubing, minimizing the use of sharp 90° bends.
4. Insulate the entire gas line and its fittings.
5. Do NOT allow uninsulated liquid line to come in direct
contact with bare gas line.
6. Precautions should be taken to avoid heat damage to
the pressure tap valve core during brazing. It is recom-
mended that the pressure tap port valve core be removed
and a wet rag wrapped around the valve body.
NOTICE: Use care to make sure that no moisture enters pressure
tap port, while wet rag is being used.
Pub. No. 11-AC24D1-1
1/4 TURN ONLY
COUNTERCLOCKWISE
FOR FULL OPEN
POSITION
VALVE STEM
GAS LINE CONNECTION
INSTALLER'S GUIDE
NOTICE: Precautions should be taken to avoid heat damage to
basepan during brazing. It is recommended to keep the flame
directly off of the basepan.
7. Use a Dry Nitrogen Purge and Brazing Alloy without flux when
brazing the field line to the copper factory connection. Flow dry
nitrogen into either valve pressure tap port, thru the tubing and
out the other port while brazing.
8. Braze using accepted good brazing techniques.
LEAK CHECK
IMPORTANT: Replace pressure tap port valve core before
attaching hoses for evacuation.
After the brazing operation of refrigerant lines to both the
outdoor and indoor units is completed, the field brazed connec-
tions must be checked for leaks. Pressurize through the service
valve ports, the indoor unit and field refrigerant lines with dry
nitrogen to 350-400 psi. Use soap bubbles or other leak-checking
methods to see that all field joints are leak-free! If not, release
pressure; then repair!
SYSTEM EVACUATION
NOTE: Since the outdoor unit has a refrigerant charge, the gas
and liquid line valves must remain closed.
1. Upon completion of leak check, evacuate the refrigerant lines
and indoor coil before opening the gas and liquid line valves.
2. Attach appropriate hoses from manifold gauge to gas and
liquid line pressure taps.
NOTE: Unnecessary switching of hoses can be avoided and
complete evacuation of all lines leading to sealed system can be
accomplished with manifold center hose and connecting branch
hose to a cylinder of R-410A and vacuum pump.
3. Attach center hose of manifold gauges to vacuum pump.
4. Evacuate until the micron gauge reads no higher than
350 microns.
5. Close off valve to vacuum pump and observe the micron
gauge. If gauge pressure rises above 500 microns in one (1)
minute, then evacuation is incomplete or system has a leak.
6. If vacuum gauge does not rise above 500 microns in one (1)
minute, the evacuation should be complete.
7. Blank off vacuum pump and micron gauge, close valves on
manifold gauge set.
NOTE: DO NOT VENT REFRIGERANT INTO THE
ATMOSPHERE.
8. The liquid line shut-off valve can now be opened. Remove
shut-off valve cap. Fully insert hex wrench into the stem and
back out counterclockwise until valve stem just touches rolled
edge (approximately five [5] turns) observing WARNING
statement on page 2. See Figure 3.
NOTE: A 3/16" Allen wrench is required to open liquid line
service valve. A 1/4" Open End or Adjustable wrench is required
to open gas line valve. A 3/4" Open End wrench is required to take
off the valve stem cap.
9. Replace liquid service pressure tap port cap and valve stem
cap. These caps MUST BE REPLACED to prevent leaks.
Replace valve stem and pressure tap cap finger tight, then tighten
an additional 1/6 turn.
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