172-65188M-08 (
M-COS 3,16,21
Pressure Reducing Valve) 24 Jun 2015
20
Operation Procedures
1. Turn ON the power to the controller. (Thereupon, LEDs for power ON and for the
pressure indicator are lighted.)
Make sure that the pressure lock switch is turned OFF.
2. Set the maximum allowable pressure.
With the selector switch set at the maximum allowable pressure side, operate the
maximum allowable pressure setting knob to set the desired maximum allowable
pressure. When no setting is made for the upper limit, set at a value equivalent to
the maximum set pressure plus 100 kPa.
When the setting has been completed, shift the selector switch to the measured
pressure side.
3. Set the pressure with the pressure setting lever switch.
While reading the measured value given on the pressure indicator, adjust the
pressure setting by pushing the lever switch either toward the UP side (if the
pressure is to be raised), or toward the DOWN side (if it is to be lowered). In
order to avoid possible overshooting the desired set value if the switch is pressed
continuously, retract the switch temporarily to a point 20 to 50 kPa before the
target pressure, and thereafter, set by fine adjustment to the exact desired
pressure. As long as the pressure setting lever switch is depressed, the pressure
setting value continues changing at a rate of about 20 to 40 kPa per second. Use
this as the guideline in case there is a delay in the change of the pressure
indication due to a large volume of steam space, for example.
Where the maximum allowable pressure has been set, if the pressure rises to that
maximum allowable pressure, the internal pressure switch is activated (the
allowable maximum pressure LED is lighted). The UP side of the lever switch
becomes inactive, inhibiting further adjustment for the UP side until the measured
pressure has fallen below the maximum allowable pressure setting by at least 30
kPa (whereupon the maximum allowable pressure LED light goes out).
4. If the set value is to be fixed, upon completion of the setting, turn ON the
pressure lock switch and keep it at the ON condition. Then, the set value will not
change even if the pressure set lever switch is operated by mistake. If it is
desired to change the set value, first turn OFF the lock switch and then operate
the pressure setting lever switch.
Manual Operation
If automatic controlled operation via the
controller becomes impossible, due to a power
failure or otherwise, switch over to manual
operation by the following method:
Using a wrench, turn the hexagon portion of
the pressure-adjustment screw below the
actuator (distance across flats: 24 mm).
(Required tightening torque: Max. 5 N
⋅
m)
Pressure increases by turning clockwise (from top view).
Pressure falls by turning counterclockwise.
Hexagon part of
pressure-adjustment
screw distance
across flats: 24mm
