General information
15
Intrinsic safety operation for increasing pressure
The figure shows a section of the intrinsic safety bellows for increasing pressure.
When pressure increases, the contact lever interrupts the connection between terminals 1
and 2. Should the internal bellows pierce, the pressure will be sent to the external bellows.
The external bellows surface is three times higher than the one of the internal bellows. The
connection between terminals 1 and 2 is interrupted. Should the external bellows pierce,
atmospheric pressure will be present between the two bellows.
The contact system interrupts the connection between terminals 1 and 2. Thanks to the dou-
ble bellows structure, in case of breakage, fluid will not leak into the environment.
OPERATING PRESSURE SWITCH (2 for EXP version; 1 for IT version)
Device that controls the generator pressure and keeps it within the preset value.
Instructions for calibration
The electric switch has three screws (1-2-4 from left to right). Upon reaching the set pressure the contact 1-2 is switched into
contact 1-4.
Pressure switch calibration
–
Rotate the knob (1) until setting the index of the scale (2) to the pressure value at which you wish the burner to restart.
–
Remove the cover of the pressure switch and set the drum (3) to the value selected for the differential (burner stop) based on
the “Scale of the differential regulation disc”.
1
2
3
Scale of the differential regulation disc
Example
Pressure switch type:
RT 5
Scale index:
9 bar
Drum index:
4 corresponding to 2.1 bar
Burner start:
9 bar
Burner stop:
11.1 bar
LEVEL
LEVEL INDICATOR
The level indicator consists of a pair of valves connected to a reflecting box containing a prismatic glass.
This appliance is connected to the generator above and below the normal water level, while at the lower end it is equipped with
a purge valve to evacuate the sludge and keep the glass clean.
Cooke Industries - Phone: +64 9 579 2185 Email: [email protected] Web: www.cookeindustries.co.nz
