How To Install Automatic Discharge Valve; Air Receiver Tank; Reciprocating Compressor And Parallel Piping - Hitachi NEXT Series Instruction Manual

5.4.3 How to Install Automatic
Discharge Valve
Discharge
Air Stop Valve
Pressure
detecting

Air Receiver Tank

piping
The air compressor is equipped with AUTO restart/
stop function as a standard function. The pressure for
capacity control is detected at the secondary side of the
motorized isolation valve. Install the motorized
isolation valve and pressure detecting piping (standard
accessor y). Connect the pressure detecting piping
from upper side of main piping to pressure detecting
port of the air compressor as above.
Install the pressure detecting piping as close as
motorized isolation valve. The operation with NOT
installed pressure detecting piping results in the air
relief valve action.
IMPORTANT
The motorized isolation valve is closed when the air
compressor is stop. The operation WITHOUT the
motorized isolation valve results in the backflow of
condensate from the plant compressed air system. Then
it results in the early damage of check valve, aftercooler
and etc by rusting
5.4.5 Reciprocating Compressor and
Parallel Piping
Stop Valve
Discharge Air
Stop Valve
Piping to air receiver
tank outlet
5. INSTALLING AND PIPING [Piping the Air Compressor]
Motorized isolation
Flange
Check Valve
5.4.4 Air Receiver Tank
Discharge
Air Stop Valve
Motorized
isolation valve
Air Receiver Tank
CAUTION
Failure to install an adequately sized air
receiver tank may cause the air compressor to
frequently load/unload. This may shorten the
mechanical life of the air compressor.
① Install the air receiver tank because this air
compressor is equipped with 2-step capacity control
system. To prevent the pressure fluctuation and to
maximize the energy saving feature, the minimum size
of the air receiver tank is indicated in the table blow.
Dis.Pressure
Model
psi [MPa]
DSP-90A6N
DSP-90W6N
DSP-90VA6N
100/125
DSP-90VW6N
DSP-110A6N [0.69/0.86]
DSP-110W6N
DSP-110VA6N
DSP-110VW6N
② Install the air receiver tank of 620 USgal (2.26m
for the AUTO operation, multi-unit control or lead/lag
operation in order to achieve the better energy saving effect.
③ Install the air receiver tank of 620 USgal (2.26m
more for using ECOMODE in order to achieve the
better energy saving effect on all load ratio.
IMPORTANT
・ This is to prevent the reciprocating compressor's air
pulsation from affecting this air compressor.
・ Typical operation is to run this air compressor as long
as possible as the primary and start, and stop the
reciprocating air compressor in parallel as a floating
trim air compressor, as required by the compressed air
demand.
CAUTION
Do not install a check valve between this air
compressor and the air receiver tank. This
could result in short cycling (frequent loading
and unloading) and operating problems to the
capacity control system.
Pressure detecting piping
Flange
Minimum Capacity of
Air Receiver Tank US gallon [m ]
3
620
[2.26]
) of more
3
) of
3
43