Liquid Line Service Valve - Lennox Diplomat 10HP12 Information

IMPORTANT
A schrader valve is not provided on the liquid line
service port. Valve must be backseated to turn off
pressure to service port.

LIQUID LINE SERVICE VALVE

STEM CAP
KNIFE EDGE SEAL
VALVE STEM
USE SERVICE
WRENCH
(PART #18P66,
VALVE
54B64 or 12P95)
BACKSEATED
OUTLET
(TO INDOOR COIL)
(FROM OUTDOOR COIL)
TO LINE SET
KNIFE EDGE
SEAL
STEM CAP
VALVE STEM
USE SERVICE WRENCH
(PART #18P66)
TO LINE SET
IMPORTANT
A schrader valve is not provided on the liquid line
service port. Valve must be backseated to turn off
pressure to service port.
FIGURE 18
To Access Service Port:
1 – Remove the stem cap. Use a service wrench
(part #18P66, 54B64 or 12P95) to make sure the
service valve is backseated.
2 – Remove service port cap and connect high pressure
gauge to service port.
3 – Using service wrench, open valve stem (one turn
clockwise) from backseated position.
SERVICE PORT
CLOSED TO LINE SET
AND UNIT
(NO PRESSURE)
INLET
SERVICE PORT CAP
TO OUTDOOR UNIT
(COIL)
SERVICE PORT
OPEN TO
LINE SET
AND CLOSED
TO UNIT
TO OUTDOOR
UNIT (COIL)
VALVE FRONT
SEATED
Page 9
4 – When finished using port, backseat stem with
service wrench. Tighten firmly.
5 – Replace service port and stem cap. Tighten finger
tight, then tighten an additional 1/6 turn.
To Close Off Service Port:
1 – Using service wrench, backseat valve.
a – Turn stem counterclockwise.
b – Tighten firmly.
To Open Liquid Line Service Valve:
1 – Remove the stem cap with an adjustable wrench.
2 – Using service wrench, backseat valve.
a – Turn stem counterclockwise until backseated.
b – Tighten firmly.
3 – Replace stem cap, finger tighten then tighten an
additional 1/6 turn.
To Close Liquid Line Service Valve:
1 – Remove the stem cap with an adjustable wrench.
2 – Turn the stem in clockwise with a service wrench to
front seat the valve. Tighten firmly.
3 – Replace stem cap, finger tighten then tighten an
additional 1/6 turn.
2 – Vapor Line Service Valve
WARNING
Do not attempt to backseat this valve. Attempts
to backseat this valve will cause snap ring to
explode from valve body under pressure of
refrigerant. Personal injury and unit damage will
result.
A full service non-backseating vapor line service valve
is used on all 10HP series units. Different manufacturers
of valves may be used. All vapor line service valves
function the same way, differences are in construction.
Valves manufactured by Parker are forged assemblies.
Valves manufactured by Primore and Aeroquip are
brazed together. Valves are not rebuildable. If a valve
has failed it must be replaced. The vapor line service
valve is illustrated in figure 19.
The valve is equipped with a service port. A schrader
valve is factory installed. A service port cap is supplied
to protect the schrader valve from contamination and
assure a leak free seal.
To Access Schrader Port:
1 – Remove service port cap with an adjustable wrench.
2 – Connect gauge to the service port.
3 – When testing is completed, replace service port
cap. Tighten finger tight, then tighten an additional
1/6 turn.