Trane 4TWX8 Installer's Manual page 10

STEP 2 - Remove the pressure tap cap and
valve cores from both service valves.
STEP 3 - Purge the refrigerant lines and indoor
coil with dry nitrogen.
STEP 4 - Wrap a wet rag around the valve body
to avoid heat damage and continue the dry nitro-
gen purge.
Braze the refrigerant lines to the service valves.
For units shipped with a field-installed external
drier, check liquid line filter drier's directional flow
arrow to confirm correct direction of refrigeration
flow (away from outdoor unit and toward evapo-
rator coil) as illustrated. Braze the filter drier to
the Liquid Line.
Continue the dry nitrogen purge. Do not remove
the wet rag until all brazing is completed.
Important: Remove the wet rag before stopping
the dry nitrogen purge.
Note: Install drier in Liquid Line.
NOTE: Precautions should be taken to avoid Precautions should be taken to avoid
NOTE:
heat damage to basepan during brazing. It is heat damage to basepan during brazing. It is
recommended to keep the flame directly off recommended to keep the flame directly off
of the basepan. of the basepan.
10
3-4" from valve
18-BC91D1-6B-EN