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Additional equipment required to complete installation for a
CONTINUOUS
sample method of control:
1.
Fully ported shut off valve for blowdown line
. Allows for the removal of the electrode while the
boiler is on.
2.
Adjustable flow control valves or orifice unions with various sized plates
. Controls sampling rate,
blowdown rate, and ensures back pressure at the electrode to prevent flashing.
3.
Motorized or solenoid operated valve, normally closed
. Controls the opening and closing of the
auxiliary blowdown line.
4.
One quarter (1/4) turn mechanical ball valve
. For flushing the probe line.
4.8 Boiler Start-Up
Determine if the application requires timed or continuous sampling as per the sizing information in this manual.
4.9 Timed Sample Start-Up
1. Check that the unit is installed as shown in Figure 7 Timed Sample on page 30.
2. Complete the Pre-Start-Up Work Sheet on page 26.
3. Supply power to the DC4000 controller.
4. Place the unit in the Manual Output mode and activate the control relay. This will test the motorized
blowdown valve.
5. Take a boiler water sample and calibrate as needed.
Wait until the reading stabilizes before adjusting the calibration.
The interval should be frequent enough to ensure that conductivity levels don’t rise too high between samples
.
The sample duration should be long enough to allow the reading on the display to stabilize before the sample period
ends. A good starting point is a sample interval of 30 minutes and a duration of 60 seconds. Make any other needed
changes in
Set-Up
.
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