Lennox Merit Series 13HPX Units Installation Instructions Manual page 13

Torque Requirements
When servicing or repairing heating, ventilating, and air
conditioning components, ensure the fasteners are
appropriately tightened. Table 3 lists torque values for
fasteners.
TORQUE REQUIREMENTS
Parts Recommended Torque
Service valve cap 8 ft.- lb.
Sheet metal screws 16 in.- lb.
Machine screws #10 28 in.- lb.
Compressor bolts 90 in.- lb.
Gauge port seal cap 8 ft.- lb.
IMPORTANT
To prevent stripping of the various caps used, the
appropriately sized wrench should be used and fitted
snugly over the cap before tightening.
Using Manifold Gauge Set
When checking the system charge, only use a manifold
gauge set that features low loss anti-blow back fittings.
Manifold gauge set used with HFC-410A refrigerant
systems must be capable of handling the higher system
operating pressures. The gauges should be rated for use
with pressures of 0 - 800 psig on the high side and a low side
of 30" vacuum to 250 psig with dampened speed to 500 psi.
Gauge hoses must be rated for use at up to 800 psig of
pressure with a 4000 psig burst rating.
OPERATING BALL TYPE SERVICE VALVE:
1. Remove stem cap with an appropriately sized wrench.
2. Use an appropriately sized wrenched to open. To open valve,
rotate stem counterclockwise 90°. To close rotate stem
clockwise 90°.
TO OPEN ROTATE STEM
COUNTERCLOCKWISE 90°.
TO CLOSE ROTATE STEM
CLOCKWISE 90°.
SERVICE PORT
SERVICE PORT
CORE
SERVICE PORT
CAP
FIGURE 14
TABLE 3
11 NM
2 NM
3 NM
10 NM
11 NM
BALL (SHOWN
CLOSED)
STEM CAP
OPERATING ANGLE TYPE SERVICE VALVE:
1. Remove stem cap with an appropriately sized wrench.
2. Use a service wrench with a hex-head extension (3/16" for liquid
line valve sizes and 5/16" for vapor line valve sizes) to back the
stem out counterclockwise as far as it will go.
When service valve is OPEN, the service port is
open to line set, indoor and outdoor unit.
When service valve is CLOSED, the service port is
NOTE — A label with specific torque requirements may be affixed to the
stem cap. If the label is present, use the specified torque.
A service port cap protects the service port core from contamination and
serves as the primary leak seal.
1. Remove service port cap with an appropriately sized wrench.
2. Connect gauge set to service port.
3. When testing is completed, replace service port cap and tighten as
follows:
•
With torque wrench: Finger tighten and
torque cap per table 3.
•
Without torque wrench: Finger tighten and
use an appropriately sized wrench to turn
an additional 1/6 turn clockwise.
VALVE
Reinstall Stem Cap:
STEM
Stem cap protects the valve stem from damage and serves as the
primary seal. Replace the stem cap and tighten as follows:
•
With Torque Wrench: Finger tighten
and then torque cap per table 3.
•
Without Torque Wrench: Finger
tighten and use an appropriately
sized wrench to turn an addition­
al 1/12 turn clockwise.
Page 13
SERVICE PORT CAP
SERVICE PORT CORE
(VALVE STEM SHOWN OPEN)
INSERT HEX WRENCH HERE
STEM CAP
ANGLE-TYPE SERVICE VALVE
(BACK-SEATED OPENED)
(VALVE STEM SHOWN CLOSED)
INSERT HEX WRENCH HERE
ANGLE-TYPE SERVICE VALVE
(FRONT-SEATED CLOSED)
open to the line set and indoor unit.
FIGURE 15
TO ACCESS SERVICE PORT:
FIGURE 16
1/6 TURN
11 12
1
2
10
9 3
4
8
5
7
6
1/12 TURN
11 12
1
2
10
9 3
4
8
5
7
6
13HPX SERIES