Lennox XC20-036-230-01 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 manifold gauge set connections.
6
BRAZE LINE SET
Wrap both service valves with water-saturated cloths as illustrated here and as mentioned in step 4, before brazing to line set. Cloths
must remain water-saturated throughout the brazing and cool-down process.
- Allow braze joint to cool. Apply additional
IMPORTANT
water-saturated cloths to help cool brazed joint. Do not
remove water-saturated cloths until piping has cooled.
Temperatures above 250ºF will damage valve seals.
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.
7
PREPARATION FOR NEXT STEP
Disconnect manifold gauge set from service ports after all connections have been brazed. Apply additional water-saturated cloths to both
service valves to cool piping. Once piping is cool, remove all water-saturated cloths.
XC20
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
WARNING
SUCTION LINE
Figure 9. Brazing Procedures (Continued)
LIQUID LINE SERVICE VALVE
SUCTION LINE SERVICE
18
WATER-SATURATED
CLOTH
LIQUID LINE
VALVE
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
WATER-SATURATED
CLOTH