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3. Pneumatic Control Panel
The pneumatic control panel of a 2-Way Tilt dryer has two (2) tilting solenoid valves, one to control the front
set of tilting pistons and a second to control the rear set of tilting pistons. A 1-Way Tilt dryer has only one (1)
tilting solenoid valve.
Each valve has five (5) 1/2-inch F.P.T. ports and two (2) electric solenoids, one on each side of the valve.
To tilt the dryer back, a 120 volt signal is applied to the front pistons solenoid connector #S5, and no voltage
is applied to the solenoid connector #S8. The internal spool in the valve will move and 80 PSI of air will enter
the bottom port of the front tilting pistons, extending the front tilting piston rods and tilting the dryer back for
loading. The top piston ports are bled to the atmosphere. To level the dryer after loading, the voltage signals
are reversed. No voltage is applied to the “S5” solenoid, and 120 volts are applied to the “S8” solenoid. The
valve spool will now move so that 80 PSI of air is applied at the top piston ports, while the bottom piston ports
are bled to the atmosphere. The piston rods will now retract, leveling the dryer. On 2-Way Tilt dryers, the
rear tilting piston solenoid valve acts in the same manner.
The tilting piston valves are 3-position valves. This means that, if no voltage is applied to both positions
“S5” and “S8”
ALL
five (5) valve ports are blocked. If the dryer is tilting or leveling and power to the dryer
is shut off, the pistons will lock in position, holding the dryer in a partially tilted position.
The dryer can be made to tilt faster or slower by adjusting the pistons 3/8” flow control valves which are
located on the pneumatic control panel.