Aquatec DC 500, User Manual, Page: 8 / 25

8
Long term preservation (mothballing) of the plant
Prior to a longer period of shutdown, the Aquatec has to be preserved with chemical
no. 3 (Biocide). After mothballing, the plant can be shut down for 6 months,
depending on the environmental conditions. For a longer period of shutdown, the
long term preservation has to be repeated every 6 months.
If there is the risk of frost, the entire pressure pipe with internal membrane in the pipe
should be dismounted (after necessary preservation) and be stored frost-proof with
closed hose connections. Water in the filters, feed pump and in the high-pressure
pump has to be drained. Can the membrane not be removed alternatively 20%
glycerin in food quality can be added as an antifreeze to the biocide at preservation.
Attention : The conservation chemical no. 3 is a Biocide. Please consider the hazard
notes on the canisters. Working with chemicals, please wear protective glasses,
breathing protection and rubber gloves for your own safety.
Instruction for mothballing of the Aquatec. Working pressure 0 bar!!!
1) Close the seawater intake valve.
2) Open the pressure control valve entirely, turn the product water three-way valve
(no. 2) to position test-outlet.
3) Rinse the system with fresh water as described in “Fresh water flushing”.
4)
Turn the three-way valve (4) according to the flow diagram “Long term
preservation (mothballing) of the plant”. Open valve (1).
5) Mix the required amount of Biocide corresponding to the instructions on the
package (chemical no. 3) with 1 to 2 litres chlorine-free freshwater, until the
powder is fully dissolved. Since there are about 1,5 liters of water already in each
membrane and 1 liter of water in each filter, please add the according amount of
chemical to the water that has to be blended in every membrane and filter.
6) Fill the solution into the tank for conservation.
7) Switch on the feed pump and the high-pressure pump. Let the Biocide circulate
through the system for about 10 minutes.
8) The Biocide in the tank can be discharged overboard after turning the three-way
valve (4). It should be noted that the system gets no air. Switch off the system
immediately before the tank has been completely emptied.
9) Possibly turn the valves in a position that prevents leakage of conservation liquid
from the membranes. The Biocide should stay in the system to prevent that the
membranes dry out.
Attention:
At every recommissioning after cleaning or mothballing, divert the product water over
the test-outlet for the first 30 minutes to rinse the chemical completely out of the
system.