Lennox XC25-024-230-01 Installation And Service Procedure page 18

WRAP SERVICE VALVES
4
To help protect service valve seals during brazing, wrap water-saturated cloths around service valve bodies and copper tube
stubs. Use additional water-saturated cloths underneath the valve body to protect the base paint.
5 FLOW NITROGEN
Flow regulated nitrogen (at 1 to 2 psig) through the
refrigeration gauge set into the valve stem port connection
on the liquid service valve and out of the suction / vapor
valve stem port. See steps 3A, 3B and 3C on previous page
and below for manifold gauge setup.
6
BRAZE LINE SET
Cloths must remain water-saturated throughout the
brazing and cool-down process.
Braze liquid line to liquid line service valve.
A.
Braze suction / vapor line to suction / vapor
B.
service valve.
IMPORTANT !
Use silver alloy brazing rods with 5%
minimum silver alloy for copper-to-copper
brazing and 45% alloy for copper-to-brass
or copper-to-steel brazing.
SUCTION / VAPOR LINE
IMPORTANT !
Allow braze joint to cool. Apply additional
water-saturated cloths to help cool brazed
joints. Do not remove water-saturated cloths
until piping has cooled. Temperatures above
250ºF will damage valve seals.
7
PREPARATION FOR NEXT STEP
After all connections have been brazed, disconnect manifold gauge set from service ports. Apply additional water-saturated
cloths to both services valves to cool piping. Once piping is cool, remove all water-saturated cloths. Refer to the unit installation
instructions for the next step in preparing the unit.
XC25
6B
WATER-SATURATED CLOTHS
LIQUID LINE
WATER-SATURATED
CLOTHS
Figure 9. Brazing Procedures (Continued)
1. FIRE, PERSONAL INJURY, OR PROPERTY
DAMAGE will result if you do not wrap a water-
saturated cloth around both liquid and suction line
service valve bodies and copper tube stub while
brazing in the line set! The braze, when complete,
must be quenched with water to absorb any
residual heat.
2. Do not open service valves until refrigerant lines
and indoor coil have been leak-tested and
evacuated. Refer to procedures provided in this
supplement.
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
6A
18
WARNING
SUCTION / VAPOR SERVICE PORT
MUST BE OPEN AND SERVICE PORT
CORE REMOVED TO ALLOW EXIT
POINT FOR NITROGEN FLOW