Service Valves - Lennox HP21 Series Installation Instructions Manual

CHARGE
COMPENSATOR
HIGH
PRESSURE
SWITCH
DISCHARGE
MUFFLER
COMPRESSOR
CHECK AND
EXPANSION
VALVE

Service Valves

The liquid line and vapor line service valves (figure 7) and
and gauge ports are used for leak testing, evacuating,
charging and checking charge. See table 2 for torque re-
quirements.
Each valve is equipped with a service port which has a fac-
tory−installed Schrader valve. A service port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.
Table 2
Torque Requirements
Part
Service valve cap
Sheet metal screws
Machine screws #10
Compressor bolts
Gauge port seal cap
HP21 Cooling Cycle
(Shows Gauge Manifold Connections)
REVERSING
ACCUMULATOR
LOW
PRESSURE
CONNECTION
HEATING
CYCLE
LOW
PRESSURE
CONNECTION
COOLING
CYCLE
FILTER/DRIER
(BI−FLOW)
Outdoor Unit
Recommended Torque
8 ft.− lb. 11 NM
16 in.− lb. 2 NM
28 in.− lb. 3 NM
90 in.− lb. 10 NM
8 ft.− lb. 11 NM
LOW
PRESSURE
VALVE
VAPOR LINE
VALVE
LIQUID LINE
VALVE
Figure 13
Service valves are closed to the outdoor unit unit and
open to line set connections. Do not open until refrig-
erant lines have been leak tested and evacuated. All
precautions should be exercised in keeping the sys-
tem free from dirt, moisture and air.
Accessing the Schrader Port:
1 − Remove the service port cap with an adjustable wrench.
2 − Connect the gauge to the service port.
3 − When testing is complete, replace the service port cap.
Tighten finger tight, then tighten an additional 1/6 turn.
Opening Liquid or Vapor Line Service Valve:
1 − Remove the stem cap with an adjustable wrench.
2 − Use a service wrench with a hex head extension to back
the stem out counterclockwise as far as it will go.
NOTE − Use a 3/16" hex head extension for liquid line
sizes or a 5/16" extension for vapor line sizes.
3 − Replace the stem cap. Tighten finger tight, then tighten
an additional 1/6 turn.
Page 12
HIGH
PRESSURE
CHECK AND
EXPANSION
VALVE
Indoor Unit
IMPORTANT