World Leaders in Ultra-Pure Heating
Revision 10
www.heateflex.com
01/17/13
405 E. Santa Clara St.
Arcadia, CA 91006-7218
Tel: (626) 599-8566 Fax: (626) 599-9567
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4.3.5. Hot Valve Over-Temperature
Hot valve over temperature protection is provided by a thermocouple, which senses the D.I.
temperature on the hot-side mixing valve. This thermocouple acts as an input to the Auto-
Shutdown System, which will close the pneumatic ball valve on the steam supply inlet to the
exchanger if the D.I. water temperature at the hot-side manifold valve exceeds a factory default
setting. The default Hot Valve Over-Temperature Alarm and Hot Valve Over-Temperature
Alarm Delay set points are 121
o
C and 10 seconds respectively.
Note: The Hot Valve Over Temperature alarm set point and alarm delay are set by the
Factory and can not be modified.
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4.3.6. Low D.I. Flow Rate
The flow rate through the system is continuously monitored by a flow meter. If the flow meter
detects a flow rate that is below the factory set value, a Low Flow Rate alarm is triggered
which initiates an Auto-Shutdown of the steam valve. In order to clear this alarm condition the
flow rate must be greater than the factory flow rate alarm set point. There is a default alarm
delay of 20 seconds when this alarm is triggered. In addition this alarm condition needs to be
reset manually by pressing the “ALARM RESET” button. The factory flow rate alarm set
point will vary model to model. Please refer to Section 8.3.2 Fluidix PC Factory Default
Parameters for the actual set point value.
Note: The Low Flow Rate alarm set point and alarm delay are set by the Factory and can
not be modified.
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4.4 Auto-Isolation System
The Auto-Isolation System is automatically activated by any of the following conditions: open
contact on the customer interface strip, manual initiation on the System Status screen of the
main or remote panels, during the Low Process Pressure Alarm condition when in Auto Mode,
or loss of power at the main panel. When an auto-isolation occurs, the pneumatic isolation
valves at the D.I. water inlet and outlet will react by opening or closing, audio alarms on both
the main and user‟s remote panels will be energized, and the corresponding alarm will become
active. An external input is also provided so the Auto-Isolation System can be activated from a
remote location by the user or interfaced to another piece of equipment.
The Auto-Isolation System is comprised of two different types of pneumatic diaphragm air
operated valves (AOV) which are either fail-safe close or fail-safe open. These AOVs open or
close when pressurized with instrument air controlled by a solenoid valve.
