8. Startup
Warning
Some chemicals react with water, which can lead to
explosions. If the dosing medium can react with
water, the DSS system must be flushed with a
medium compatible with both water and the dosing
medium first, to remove remaining water in the DSS
system.
Prior to startup, flush all tanks and pipes.
Caution
An initial test can be made with water if the dosing
medium is compatible with water.
The DSS system is tested for tightness in the factory.
Note
Note
Some residual water may still be present in the
fittings and pipes.
1. Retighten all threaded joints.
2. Check the tightness of the entire DSS system and all pipes.
3. Check the electrical wiring and the power supply.
4. For dosing pumps with three-phase motors, additionally check
the direction of rotation and the setting of the motor
protection.
5. If installed in a suction lift application, install the inlet line with
a foot valve in the dosing tank.
– Install the inlet line with a continuous upward slope towards
the dosing pump.
6. Open the isolating valves for the dosing pump.
7. Vent the pump.
For details on venting the dosing pump, see installation and
operating instructions for the dosing pump.
Optional procedure for venting a dosing pump via the sample
or bleed valve:
– Add a hose to the sample or bleed valve that directs the
medium to a drain or back to the dosing tank.
– Open the sample or bleed valve.
– Start the pump and continue pumping until medium flows out
of the sample or bleed valve.
– Stop the pump and close the sample or bleed valve. The
hose can either be removed or stay.
8. Check the proper interaction of all electronic signal
accessories such as leakage detection, level switch, alarm
relay, with the controller of the installation.
9. Adjust the settings of the pressure relief valve, back pressure
valve and pulsation dampener as required for the application.
See the manufacturer's instructions.
8.1 Calibration
Calibration must be done with the dosing medium. For details on
calibration, see installation and operating instructions of the
dosing pump.
9. Operation
In normal operation, the DSS system operates independently.
•
Do not close the isolating valves on the outlet side of the pump
during normal operation.
– Otherwise the pressure relief valve will open.
•
Keep all isolating valves closed that are not in the line
between the dosing medium inlet and the injection point, e.g.
valve of the calibration column; the inlet isolating valve and
outlet isolating valve of the dosing pumps; and sample or
bleed valve. The operator decides which pump is the duty
pump and which is the standby pump.
•
Do not close or block the vent hole of the dosing tank.
•
Do not contaminate the dosing tank.
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