Lennox Dave Signature XP21 Installation Instructions Manual page 16

CAUTION
Brazing alloys and flux contain materials which are
hazardous to your health.
Avoid breathing vapors or fumes from brazing
operations. Perform operations only in well-ventilated
areas.
Wear gloves and protective goggles or face shield to
protect against burns.
Wash hands with soap and water after handling brazing
alloys and flux.
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 under 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.
A. Braze liquid line to liquid line service valve.
B. Braze vapor line to vapor service valve.
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.
VAPOR LINE
WATER-SATURATED
LIQUID LINE
WATER SATURATED
FIGURE 15
Page 16
WARNING
Danger of fire. Bleeding the refrigerant
charge from only the high side may result
in pressurization of the low side shell and
suction tubing. Application of a brazing
torch to a pressurized system may result
in ignition of the refrigerant and oil
mixture. Check the high and low
pressures before applying heat.
FIRE, PERSONAL INJURY, OR PROPERTY DAMAGE
may 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 the line set! The braze, when
complete, must be quenched with water to absorb any
residual heat.
Do not open service valves until refrigerant lines and
indoor coil have been leak-tested and evacuated. Refer
to Installation and Service Procedures manual found on
DAVENET.
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
6B
CLOTHS
6A
CLOTHS
WARNING
VAPOR SERVICE PORT MUST
BE OPEN AND SERVICE PORT
CORE REMOVED TO ALLOW
EXIT POINT FOR NITROGEN
FLOW