Precautions In Servicing The Models With New-Type Refrigerant; Tools Required - Daikin VRV Plus Series General Information Manual

Si33-003.book Page 168 Monday, June 25, 2001 9:06 AM

Precautions in Servicing the Models with New-type Refrigerant

1. Precautions in Servicing the Models with New-type
Refrigerant
Compared to the conventional refrigerant R22, the brand-new refrigerant R-407C is higher in pressure.
The refrigerant oil is also different in type. With this in mind, note that the piping work procedures as well as
the related tools and piping materials are partially different than ever before.
Refrigerant
Refrigerant oil
Condensation pressure
1.1

Tools Required

Some specific tools are required for servicing the refrigerant line of the new-type refrigerant models. Select
the right tools referring to the table below.
Typical tools and materials for piping works and their interchangeability
Name
Pipe cutter Refrigerant piping
work
Flaring tool
Refrigerant oil
Torque wrench
Pipe expander
Pipe bender
Nitrogen Air-tightness test
Welder
Gauge manifold Air-tightness test thru
refrigerant recharging
Charging hose
Vacuum pump Vacuum drying
Charging cylinder Refrigerant recharging
Refrigerant charging
scale
Gas leak detector
168
Conventional type
R22 (single)
Mineral oil (Suniso)
1.84MPa
Work process and application
Cutting pipes
Flaring pipes
Applying on flared spots
Connecting flare nut
Expanding pipes at
connections
Bending pipes
Inhibiting oxidation in pipes
Brazing pipes
Vacuum refrigerant
charging and running test
Gas leak test
New type
R-407C (mixed)
Synthetic oil (ether)
2.01MPa
Interchangeability with conventional tools and materials
Interchangeable.
Specified ether oil, ester oil, alkyl benzene oil or their mixture to
be used.
Interchangeable.
Specific tools required for boosting the pressure and preventing
impurities from coming in.
Interchangeable.
(Adapter to be connected to keep the oil from flowing back to
the unit during pump shut-down. Pump with anti-backflow
function also available.)
Conventional cylinder not allowed because of different
refrigerant properties. (Need to weigh with the scale.)
Interchangeable.
Specific detector needed. (R134a-compatible detector
allowed.)
: http://splitoff.ru/tehn-doc.html
New Refrigerant R-407C
SiE33-003