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HDK-MT350_EN_06
► With the aid of special tool (Item 4), fit valve seat (11) in the hole and push in
as far as it will go.
► Using special tool (Item 3), fit piston (13), compression spring (14) and bush
(15) together in the hole.
► Insert the ring (16).
► Screw in screw plug (17) and tighten (tightening torque 66 Nm).
► Check that all screw connections are tight.
► If no other maintenance work is to be carried out: Restart the dryer (see
page 36).
Replacing pilot control units
The pilot control units are wear parts and should be replaced every 24 months.
Take care not to damage the valve block!
Valve seats and installation holes should be cleaned prior to assembly to
ensure they are free of dust and particles.
The valve seats of the pilot control unit are prone to misalignment.
To ensure you do not damage the valve seat, the end sleeve must always
be removed with the solenoids energised.
Note!
In addition to the required safe working procedures, the following
criteria must be observed when disassembling and assembling the valves
and pilot control units of the dryer.
The arrangement of the pilot
control units is shown in the figure
opposite:
Y1, Y2
Pilot control unit of the main valves
Y3, Y4, Y4
Pilot control unit of the expansion
and pressure build-up valves
Pilot control units, solenoid valve block
