Page 10
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.
IMPORTANT
Only use Allen wrenches of sufficient hardness (50Rc -
Rockwell Harness Scale minimum). Fully insert the
wrench into the valve stem recess.
Service valve stems are factory-torqued (from 9 ft-lbs for
small valves, to 25 ft-lbs for large valves) to prevent
refrigerant loss during shipping and handling. Using an
Allen wrench rated at less than 50Rc risks rounding or
breaking off the wrench, or stripping the valve stem
recess.
See the Lennox Service and Application Notes #C-08-1
for further details and information.
IMPORTANT
To prevent stripping of the various caps used, the
appropriately sized wrench should be used and fitted
snugly over the cap before tightening.
When servicing or repairing HVAC components, ensure the
fasteners are appropriately tightened. Table 3 provides
torque values for fasteners.
Table 3. Torque Requirements
Parts Recommended Torque
Service valve cap 8 ft.- lb. 11 NM
Sheet metal screws 16 in.- lb. 2 NM
Machine screws #10 28 in.- lb. 3 NM
Compressor bolts 90 in.- lb. 10 NM
Gauge port seal cap 8 ft.- lb. 11 NM
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 SERVICE VALVES
The liquid and vapor line service valves are used for
removing refrigerant, flushing, leak testing, evacuating,
checking charge and charging.
Each valve is equipped with a service port which has a
factory-installed valve stem. Figure 3 provides information
on how to access and operating both angle and ball service
valves.
To Next Page
Loading...
Need help?
General