Lennox XC21 Series Unit Information page 16

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
Water saturated cloths must remain water saturated
throughout the brazing and cool−down process.
A Braze liquid line to liquid line service valve.
B Braze suction / vapor line to suction / vapor service
valve.
SUCTION / VAPOR LINE
Allow braze joint to cool. Apply
IMPORTANT
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.
XC21
6B
WATER SATURATED CLOTHS
6A
LIQUID LINE
WATER SATURATED
CLOTHS
Figure 9. Brazing Procedures (Continued)
Page 16
WARNING
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.
SUCTION / VAPOR SERVICE PORT
MUST BE OPEN AND SERVICE PORT
CORE REMOVED TO ALLOW EXIT
POINT FOR NITROGEN FLOW