Liquid Line Service Valve - Lennox HP23 Series Manual

A – Service Valves
The liquid line and vapor line service valves and gauge
ports are accessible from outside of the unit. Full
service liquid and vapor line valves are used. See
figures 20 and 21. The service ports are used for leak
testing, evacuating, charging and checking charge.
1 – Liquid Line Service Valve
A full-service liquid line valve made by one of several
manufacturers may be used. All liquid line service
valves function the same way, differences are in
construction. Valves manufactured by Parker are
forged assemblies. Valves manufactured by Primore
are brazed together. Valves are not rebuildable. If a
valve has failed it must be replaced. The liquid line
service valve is illustrated in figure 20.

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)
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 20
The valve is equipped with a service port. There is no
schrader valve installed in the liquid line service port. A
service port cap is supplied to seal off the port.
SERVICE PORT
CLOSED TO LINE SET
AND UNIT
(NO PRESSURE)
INLET
(FROM OUTDOOR COIL)
SERVICE PORT CAP
TO OUTDOOR UNIT
(COIL)
SERVICE PORT
OPEN TO
LINE SET
AND CLOSED
TO UNIT
TO OUTDOOR
UNIT (COIL)
VALVE FRONT
SEATED
The liquid line service valve is a front and back seating
valve. When the valve is backseated the service port is
not pressurized. The service port cap can be removed
and gauge connections can be made.
The service port cap is used to seal the liquid line
service valve. Access to service port requires
backseating the service valve to isolate the
service port from the system. Failure to do so
will cause refrigerant leakage.
IMPORTANT
A schrader valve is not provided on the liquid line
service port. Valve must be backseated to turn off
pressure to service port.
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.
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
A full service non-backseating vapor line service valve is
used on all HP23 series units. Different manufacturers of
valves may be used. All vapor line service valves function
the same way, differences are in construction.
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CAUTION