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9. MAINTAINING THE DSP [How to Service the DSP Air Compressor]
■
Strainer element cleaning
The strainers for both the intercooler and after cooler
must be cleaned.
①
Stop the DSP air compressor and shut off the main
power supply. Shut the gate valve of the discharge
piping.
②
Make sure no air is coming out of the drain open-
ing (pressure is not applied to the strainer).
③
Remove the screws from the rear-left lower cover
with a screwdriver (see part No. 908, page 101).
④
Remove the cover of the strainer.
⑤
Remove the element from inside the strainer and
wash with water, etc.
⑥
Return the clean element to its former position in
the strainer.
■
Cleaning the strainer element while the
compressor is running
If the strainer needs to be cleaned while the compres-
sor is running, consult with your dealer or Hitachi
Service Station. Under ordinary circumstances, pres-
sure is applied to the strainer while the compressor is
running. You should therefore exercise maximum cau-
tion when removing the strainer.
(1) Intercooler side
①
Switch 3-way changeover valve I on the intercool-
er side from the “A” side to the “B” side.
②
Remove the element. Pressure is applied to the
strainer, so be extremely careful when opening the
cover of the strainer.
③
Clean the element and mount it by performing the
procedure in reverse order.
④
Switch 3-way changeover valve I on the intercool-
er side from the “B” side to the “A” side.
(2) After cooler side
①
Switch 2-way valve A on the after cooler side from
the “C” side to the “D” side.
②
Make sure 2-way valve B is fully closed (“E” side).
In this state, strainer side pressure is drained.
③
Remove the strainer element. If 2-way valves A
and/or B are opened even the slightest amount,
pressure is applied to the strainer. You should
therefore make certain that the valves are fully
closed.
④
If 2-way valve B is opened to the “F” side in this
state, condensate can be drained while cleaning
the strainer element.
⑤
Place the cleaned element in its former position in
the strainer and mount by performing the proce-
dure in reverse order.
⑥
Switch 2-way valve A on the after cooler side from
the “D” side to the “C” side. Also make sure
2-way valve B is fully closed.
Strainer
Element
O-ring
Cover
Loosen
Tighten
[
Strainer cleaning]
[Valve condition during conventional operation]
Ⓒ
Ⓐ
Ⓔ
2-way valve B
Strauner
Strauner
Bypass Valve pipe
Bypass Valve pipe
Aftercooler side
Intercooler side
Orifice
Orifice
Solenoid valve for drain
Solenoid valve for drain
2-way valve A
3-way changeover
valve
I
Ⓒ
Ⓐ
Ⓔ
Ⓓ
Ⓕ
Ⓑ
2-way valve B
Intercooler side
Aftercooler side
2-way valve A
3-way changeover
valve
I
[ Procedure for disassembling the strainer
element during operation]