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Step 2
(5)
Once the pressure reading of PIA has stabilized, close the air supply valve for leak testing
(AV-11).
(6)
Hold the pressure for 3 minutes and check for pressure decay.
(7)
Pressure decrease of 15 kPa (5 kPa/min) or more: leak present
Pressure decrease of less than 15 kPa (5 kPa/min): no leak
(8)
If there is a leak, an air leak test is conducted to identify the modules that have a leak.
Figure 17 Step 2 for PDT
No.
Parts
No.
Parts
AV-1
Raw water feed valve
AV-7
Air supply valve
AV-2
Filtrate valve
AV-8
Chemical supply valve
AV-3
Backwash valve
AV-9
Return valve on chemical drain side
AV-4
Return valve
AV-10
Return valve for chemical drain on
permeate side
AV-5
Drain valve
AV-11
Air supply valve for leak testing
AV-6
Drain valve
AV-12
Air-bleeding valve for leak testing
AV-5
AV-4
AV-10
AV-2
AV-3
AV-12
AV-8
AV-7
AV-1
AV-6
PI
I
PIA
I
FI
I
TI
I
PICA
PI
Drain
Air
Air
Filtration Pump
AV-11
AV-9
Feed Tank
Chemical Tank
Permeate Tank
BW Pump
Air Vent
Chemical Pump
Compressor
Receiver tank
Regulator
Flowmeter
Adjusting pressure