4.1 Tools and Refrigerant
4.1.1 Tools Required for
Installing and Servicing
– Up to 800 PSIG [5,516 kPa] High-Side
– Up to 250 PSIG [1,724 kPa] Low-Side
– 550 PSIG [3,792 kPa] Low-Side Retard
– Service Pressure Rating of 800 PSIG [5,516 kPa]
– 400 PSIG [2,758 kPa] Pressure Rating
– Dept. of Transportation 4BA400 or BW400
Ambient and Tube
at higher pressures than R-22 systems. Do not use
R-22 service equipment or components on R-410A
4.1.2 Specifications of R-410A
Application: R-410A is not a drop-in
replacement for R-22. Equipment designs must
accommodate its higher pressures. It cannot be
retrofitted into R-22 heat pumps.
Physical Properties: R-410A has an atmospheric
boiling point of -62.9°F [-52.7°C] and its saturation
pressure at 77°F [25°C] is 224.5 psig [1,548 kPa].
Composition: R-410A is a near-azeotropic
mixture of 50% by weight difluoromethane (HFC-
32) and 50% by weight pentafluoroethane (HFC-
R-410A systems operate
Pressure: The pressure of R-410A is
approximately 60% (1.6 times) greater than
R-22. Recovery and recycle equipment, pumps,
hoses, and the like must have design pressure
ratings appropriate for R-410A. Manifold sets need
to range up to 800 psig [5,516 kPa] high-side and
250 psig [1,724 kPa] low-side with a 550 psig
[3,792 kPa] low-side retard. Hoses need to have
a service pressure rating of 800 psig [5,516 kPa].
Recovery cylinders need to have a 400 psig [2,758
kPa] service pressure rating, DOT 4BA400 or DOT
Combustibility: At pressures above 1
atmosphere, a mixture of R-410A and air can
become combustible. R-410A and air should
never be mixed in tanks or supply lines or
be allowed to accumulate in storage tanks.
Leak checking should never be done with a
mixture of R-410A and air. Leak-checking can
be performed safely with nitrogen or a mixture of
R-410A and nitrogen.
4.1.3 Quick-Reference Guide
• R-410A refrigerant operates at approximately
60% higher pressure (1.6 times) than R-22.
Ensure that servicing equipment is designed to
operate with R-410A.
• R-410A refrigerant cylinders are light rose in
• R-410A, as with other HFCs, is only compatible
with POE oils.
• Vacuum pumps will not remove moisture from
POE oil used in R-410A systems.
• R-410A systems are to be charged with liquid
refrigerants. Prior to March 1999, R-410A
refrigerant cylinders had a dip tube. These
cylinders should be kept upright for equipment
charging. Post-March 1999 cylinders do not have
a dip tube and should be inverted to ensure liquid
charging of the equipment.
• Do not install a suction line filter drier in the liquid
• A factory-approved bi-flow liquid line filter drier
is shipped with every unit and must be installed
in the liquid line at the time of installation. Only
manufacturer-approved liquid line filter driers
should be used. Filter driers must have a working
pressure rating of at least 600 psig [4,137 kPa].
The filter drier will only have adequate moisture-
holding capacity if the system is properly evacuated.
• Desiccant (drying agent) must be compatible for
POE oils and R-410A refrigerant.