Toshiba MMY-MAP0806HT8P-E Installation Manual page 67

Airtightness test
After the refrigerant piping has been finished, execute an airtight test.
For an airtight test, connect a nitrogen gas canister as shown in the figure on this page and apply pressure.
• Be sure to apply pressure from the service ports of the packed valves (or ball valves) at the liquid side, gas side
and balance pipe side.
• An airtight test can only be performed at the service ports at the liquid side, gas side and balance pipe side on
header unit.
• Close the valves fully at the gas side, liquid side and balance pipe side. As there is a possibility that the nitrogen
gas will enter into the cycle of outdoor units, re-tighten the valve rods at the liquid side and balance pipe side
before applying pressure.
(When using MAP140, MAP160, MAP180, MAP200 or MAP220, you do not have to re-tighten the liquid side
valve rod as their valves at the liquid side are ball valves.)
• For each refrigerant line, apply pressure gradually in steps at the liquid side, gas side and balance pipe side.
Be sure to apply pressure at the gas side, liquid side, and balance pipe side.
WARNING
Never use oxygen, flammable gases, or noxious gases in an airtight test.
Connected to indoor unit
Main piping
Packed valve details
To outdoor unit
To gauge manifold
Liquid-side service port
Gas-side valve
Liquid-side valve
To
Balance
outdoor
To
service port
unit
outdoor Gas-side
unit service port
Balance valve
Piping at site
Piping at site
Piping at site
Connected to other follower units
131-EN
1117101201-3 EN.indd 66 1117101201-3 EN.indd 66
Low pressure High pressure
gauge gauge
Gas side valve fully closed
Gauge
V V
L H
manifold
Header outdoor unit
Service port
Brazed
Reducing
valve
Copper pipe
Fully
closed
Copper
pipe
Service port
Liquid valve fully closed
Fully Nitrogen
closed
gas
Service port
Balanced pipe side valve
fully closed
Able to detect a serious leakage
1. Apply pressure 0.3MPa (3.0kg/cm 2 G) for 5 minutes or more.
2. Apply pressure 1.5MPa (15kg/cm 2 G) for 5 minutes or more.
Available to detect slow leakage
3. Apply pressure 4.15MPa (42.3kg/cm G) for approx. 24 hours.
2
• If there is no pressure decrease after 24 hours, the test is passed.
NOTE
However, if the environmental temperature changes from the moment of applying pressure to 24 hours after that,
the pressure will change by about 0.01MPa (0.1kg/cm
the test result.
REQUIREMENT
When pressure decrease is detected in steps 1-3, check the leakage at the connecting points.
Check the leakage using a foaming agent or other measures and seal the leak with re-brazing, flare retightening
or other methods. After sealing, execute an airtight test again.
– 66 –
2 G) per 1°C. Consider the pressure change when checking
8/8/2559 BE 3:49 PM 8/8/2559 BE 3:49 PM
132-EN