Aquatec DD 500 User manual

Technical Manual
for installation, operation and maintenance of
Modular DD 500, 12 or 24 Volt
Version 68 - 02.2023
Download latest manual at:
www.aquatec-watermaker.de/downloads_E.html
In case of doubt, the German ori
g
inal manual applies.
AQUATEC- Water maker,
Manufacture and distribution b
y
North-Marine Handels GmbH
Papenre
y
e 61, D 22453 Hambur
g
.
Contac
t
sup
@
aquatec-watermaker.de, Tel: +49
(
0
)
40-36850306
Web www.aquatec-watermaker.de
All contents of this manual, in particular texts, photographs and graphics are subject to German copyright law.
Copyright held by North Marine Handels GmbH. Duplication, editing, distribution and any kind of use outside
the limits of copyright law require the written approval of the author.

2
Thank you to choose an AQUATEC Watermaker for the provisioning of fresh water on your boat.
AQUATEC equipment is made from high-quality components exclusively and has proven its reliability on long cruising-
yachts. We are convinced that our product will serve you for many years without interferences.
Recommendation for using your Aquatec reverse osmosis system.
Daily use is preferable to a one-time weekly use.
The system produces water with a neutral taste and very good quality.
Important: The drinking water must be bottled from the test outlet of the system during operation, ideally after filling the
on-board water tank. Only fill the required amount until the next operation of the plant. Clean the drinking water bottle
regularly.
If the product water from the on-board water tank is used as drinking water, follow-up-treatment is recommended. No
further treatment is usually necessary as service water.
Scope of delivery Seawater R.O. AQUATEC DD 500:
• Pump head duplex stainless steel 1.4462
• Pressure regulation-valve duplex stainless steel 1.4462
• Stainless-steel High-pressure gauge
• Stainless-steel Low-pressure gauge for feed flow
• Efficient feed pump
• Control panel cpl. mounted
• 2 pieces stainless-steel high-pressure fittings for self- assembly
• Detailed manual in German or English
• 10-liter tank for preservation and cleaning
Connection cable, through-hull fittings and sea cock must be provided on-board.
See last page for complete part list.
Option: Cruising kit DD 500
4 filter-cartridges 5 Micron, 2 filter- cartridges charcoal.
Detergents: Acid, Alkaline, Biocide (500, 400, 600 Gr.) for preservation and cleaning.
1 set low- and high-pressure gasket for hp pump,
1 set of hp pump valves (6 pc.).
O-ring spare part kit for hp pump and membrane.
This option eliminates the smaller amount of biocides included in the standard delivery.

3
This instruction includes important safety information and instructions for commissioning,
operation and maintenance of the Aquatec Watermaker components. It is essential therefore, that the
responsible specialist refers to it before starting any work on the machinery as well as prior to commissioning.
Furthermore, this instruction must always be available on site.
To ensure total satisfaction, please read this user manual carefully. Warranty will be void if the installation does not
meet this requirement. Disregarding the warnings / instructions in the User Guide and incorrect installation can lead to
serious health damage or possibly the loss of the vessel.
The following symbols and their meaning must be observed throughout the manual. Please follow the instructions and
take appropriate measures.
EXPLANATION OF SYMBOLS
Warning!
Immediate danger that
can lead to serious injury
to persons or damage to
the machine or the loss of
the vessel.
Warning!
Warnings regarding electric
power equipment. Non-
observance of safety
instructions could lead to
danger of life or limb:
Attention!
Indicates an
instruction that
requires special
attention.
Please note the following information.
Wa
r
nin
g
!
Damage to pumps and system parts due to dry running or insufficient water supply are
not covered by warranty.
Wa
r
nin
g
!
Aquatec Watermaker are designed for permanent installation on ships. Operation of
the system is only permitted with clean seawater.
Warning!
Never operate your Aquatec Watermaker unsupervised and leave the operation only
to trained persons.
Please note: If there are any leaks, the boat can fill up with water and sink, thereby
endan
g
erin
g
the life of the people on board.
Warning!
The maximum working pressure of 55 bar (800 psi) must not be exceeded.
When exceeding the specified product water quantity (seawater with lower salt content,
brackish water
)
, the workin
g
pressure must be reduced.
Warning!
Install the high-pressure pump on a stable substrate . Install the high-pressure pump in
a dry area which allows an exchange of air necessary for cooling the motor-pump unit.
The pumps may not be operated if explosive or flammable Materials are present.
Please note: The motors and pumps develop high temperatures during operation.
Touchin
g
it can cause burns.
Wa
r
nin
g
!
The installation of the hoses to the components of the system must be carried out in
compliance with the bending radii without stress and vibration (risk of breakage).
Attention!
Like any piece of mechanical equipment, the system will require inspection and service
from time to time. For easy access to enable a simple regular monitoring and proper
maintenance do not place the components in inaccessible areas.
It should be easily accessible roundly to make service and inspection work as
comfortable as possible.
Attention!
The already assembled membranes can be stored for approx. 5 months in the sealed
pressure tube, preferably cool, but preferably not above 20 ° ambient temperature.
However, we recommend installin
g
and usin
g
the Watermaker as soon as possible.

4
Table of contents
2 Scope of delivery
3 Warnings / Hints
5 Introduction reverse osmosis
6 - 7 Operation
8 - 9 Shutdown, fresh water flush.
10 - 11 Long term preservation (mothballing), antifreeze
11 - 12 Membrane cleaning
13 Memos
14 - 18 Installation
19 Electrical connection
20 Important: Inspection - maintenance - oil change
21 Change of membranes
22 – 23 Troubleshooting
24 – 27 Exploring diagram high-pressure-pump
28 Exploring diagram regulation-valve / HP-pump motor
29 - 30 Specification Dimensions
31 Part Lis
t

5
Introduction
The principle of reverse osmosis (RO)
In natural sciences and technology, osmosis is perceived as the directed migration of molecules through a
semi permeable membrane. The chemical and physical structure of the membrane determines which
molecules are able to pass and which are not. For this reason, it is called semi-permeable, which means as
much as halfway or partial permeability.
RO Membrane
If one mixes different liquids, like in this case water with different salinities, they aim to equalize their
concentration. That way, the seawater would be thinned out and the drinking water would be enriched with
salts. The effect would be a less concentrated, homogeneous dissolution. Pouring sea- and fresh water in
equal amounts into a container where both liquids are separated by an adequate semi-permeable membrane,
there would be one side with seawater that is highly loaded with salts, on the other side more or less “clean”
water without or with little dissolved components.
The natural tendency of both liquids to equalize their salinity leads to the migration of water molecules from
the fresh water side towards the seawater side. As a result, the volume of water on the fresh water side
decreases while it increases on the seawater side. This process of osmosis takes place until the pressure on
the seawater side is in accordance with the osmotic pressure. Then it stops. In this case, the osmotic pressure
is around 30 bar.
The described process however is reversible by exposing the liquid on the seawater side to mechanical
pressure. At a pressure of 30 bar, the osmotic process cannot take place or would rather be reversed. When
pressure is increased beyond 30 bar, for instance 60 bar, water molecules from the seawater side migrate to
the fresh water side. All other components of the seawater dissolution are not able to pass the membrane. As
a result, the dissolution on the seawater side remains highly-concentrated while there is a gain of fresh water
on the other side of the membrane. This process is referred to as reverse osmosis (R.O.)
The seawater is delivered to the pressure pipe’s entry side of a RO-system by a high-pressure pump. The
osmotic membrane is located in the pressure pipe and is merely permeable for the vehicle “water “(solvent)
and detaining the soluted substances. When the pressure difference is more than leveling out the osmotic
head, the water molecules are able to pass the membrane that works like a filter, while the “unpurified”
molecules are detained. In opposite to a classic membrane-filter, osmosis membranes do not have continuous
pores. In fact, the ions and molecules are migrating through the membrane by diffusing through the membrane
material. Inside of the membrane, the permeate-tube is located which transports the fresh water through one
of the two end caps of the pressure pipe towards the fresh water tank. The excess seawater, now referred to
as concentrate (brine), is drained off overboard through the outlet of the pressure pipe by a pressure control
valve.

6
Operating instructions
Attention!
Do not operate your water maker with unpurified seawater (oil, chlorine or other chemicals).
Warning!
The R.O. membranes are conserved with a dissolution that, when ingested, can cause irritations
of the gastrointestinal tract. For that reason, the product water must not be consumed within the
first 30 minutes of operating time, beforehand it has to be drained over the test-outlet. This
applies accordingly after temporary shutdown or cleaning of the membranes with the cleaning
chemicals.
Placing into operation
Attention!
Important: Check the oil level and condition of the high-pressure pump oil daily. In the
event of condensation in the oil (whitish/greyish discoloration due to continuous
operation, warm environment
)
, chan
g
e the oil immediatel
y
.
1) Open the seawater intake valve (no.10).
2) The pressure control valve (no.5) in the control panel has to be fully
opened by turning counter clockwise.
Warning! Never start your Aquatec with closed pressure control
valve!
Starting with a closed valve destroys the pressure reading and
possibly essential parts of the equipment.
An open pressure control valve can be seen when the first two
threads of the valve body becoming visible by turning the pressure
control wheel.(see picture left)
3) Turn three-way valve (no. 4) according to the flow diagram to position fresh water production. Turn three-
way valve (no. 2) to position test-outlet.
4) Switch on the feed pump. The gauge (no.9, “pressure feed water”) must show positive pressure. De-
aerate the pre-filter system if necessary and control the drain water. To prefill the system, a short fresh
water flush via the onboard pressure water pump can be useful.
5) Switch on the high-pressure pump.
6) Increase the pressure at the pressure control valve (no.5) by slowly turning it clockwise to about 30 bars.
Let the system work for about 30 seconds. There should not be any air pockets visible in the system.
7) Increase the pressure stepwise up to the maximum working pressure (55 bar, 800 psi). Test the
product water by tasting from the test outlet (at daily operation, the product water should be salt-free after
about 60 seconds). By shifting the three-way valve no. 2, the product water is fed into the fresh water
tank.
8) Important: During operation, check the entire system for leaks and smooth running. Operation is not
permitted if the s
y
stem is in a fault
y
condition.
Wa
r
nin
g
!
Never turn the pressure regulation knob completely out while the system is running. The pressure
pushes out the parts inside, which can result in injury and loss.
Attention!
If the system is operated in brackish water, seawater with a lower salt content or higher water
temperature the fresh water production must not exceed the displayed value! In this case,
regulate the pressure under continuous observation of the produced amount of water until the
normal level of fresh water production is reached. (e.g. Baltic Sea about 35 bar or 490 psi)

7
Flow diagram water production.
Hose dimensions (inner diameter) see specification
(
5
)
Pressure re
g
ulation valve
(
6
)
Flowmeter product water
(
7
)
ships fresh water pump
(
8
)
Feed pump
(
9
)
Gau
g
e feed pressure
(
10
)
Seacock
Attention!
The drinking water production changes according to the salinity, the temperature of the
seawater and the age of the R.O. membrane. The data regarding the fresh water production
apply to a salinity of 35 grams/ litre at a temperature of 25º Celsius (77° Fahrenheit) at the new
membrane.
A discrepancy up to +/- 10% also in the power consumption, especially in the
first 50 hours of operation, are usual.
At seawater temperatures below 25° C, the product water quantity is reduced by the following values. Data (approx.) In
%.
Water temperature 15° C - 20% Water temperature 5° C - 35%
Note: Hose connections for high pressure pump can
be made on the left, right or diagonally (as shown).
Inlet seawater at the bottom, high pressure at the top.

8
Switch off the system, fresh water flush
1) Open the pressure control valve until the plant runs without pressure.
2) Run the Aquatec several minutes to remove the concentrated salt from the membranes.
3) Turn three-way valve (no. 2) to position test-outlet.
4) Switch off the high-pressure pump first and then the feed pump.
5) Close the sea water intake valve.
6) Open valve (no. 3). The fresh water pressure pump of the boat should turn on now flush the system.
Duration of flushing time see “flushing time”.
7
)
Close valve
(
no. 3
)
to finish the fresh water flush.
Description fresh water flush
The fresh water rinse is activated by opening valve (no.3). For this, the seacock must be closed. When that
valve is open, fresh water could drain to the sea.
At least 10-15 liters of fresh water is required per membrane A charcoal filter removes any existing chlorine
inside the fresh water tank which destroys the membrane.
Attention!
The carbon filter ensures a chlorine separation up to 4 litres/minute. If necessary, the
performance of the on-board pressurized water system must be reduced to avoid
damaging the membranes by prevent chlorine. This note only applies when chlorine is
used in the drinking water tank.
Membrane and HP pump reduce the flushin
g
rate b
y
their internal resistance.
Flushing time:
The time needed for the fresh water rinse depends on the board-side performance of the fresh water pump
and the condition of the membranes and therefore cannot be stated on factory side.
Please find out the required amount of flushing water by discharging the rinsing water into a bucket once after
a normal operation (take off the hose at the thru-hull fitting) and check the salinity constantly by tasting. During
the process, stop the time to find out the time requirement of future flushes. By collecting it in a bucket, you
also find out the needed amount of flushing water.
Hint:
If there is no chlorine present in the fresh water tank, running the feed pump and HP-pump can accelerate the
fresh water flushing. Thanks to the well-known pump performance of the HP-pump, the necessary flushing
time can be precisely adjusted. Note: the onboard fresh water pump must provide sufficient flow. Performance
flow DD 500 ca. 3,3 litre/ minute.
Attention!
Fresh water flushing of the Aquatec is recommended after each operation. It reduced
biological growth in the membrane and preserves the life span and the reliability of the
entire system.
After each operation, the Aquatec should be rinsed with fresh water. After fresh water
flushing, the system may remain unused for 7-14 days. This process can be repeated
as desired to avoid the use of chemicals.
Attention!
Prior to a longer period of shutdown (without flushing), the Aquatec has to be preserved
with the chemical no. 3 (Biocide). For instructions, see “Long term preservation
(
mothballin
g)
of the plant”.

9
Flow diagram fresh water flush
Note!
HP- Pump always pressureless!!! (Pressure control valve (5) open).
The only application with working pressure is the production of product water.
Hose dimensions (inner diameter) see specification
(
5
)
Pressure re
g
ulation valve
(
6
)
Flowmeter product water
(
7
)
ships fresh water pump
(
8
)
Feed pump
(
9
)
Gau
g
e feed pressure
(
10
)
Seacock
Note: Hose connections for high pressure pump can
be made on the left, right or diagonally (as shown).
Inlet seawater at the bottom, high pressure at the top.

10
Long term preservation (mothballing) of the plant (Page 1 of 2)
Description:
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.
Attention!
Before preservation and longer downtime. The oil of the high-pressure pump must be
changed in order to remove any possibly existing condensation water from the oil. This
prevents corrosion of the bearin
g
s and surface of the crankshaft
Warning!
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
g
loves for
y
our own safet
y
.
Note!
If there any risk of frost, the entire pressure pipe with internal membrane in the pipe
should be dismounted (after preservation) and be stored frost-proof with closed hose
connections. The liquid present in the pressure pipe can be drained. Can the
membrane not be removed alternatively 20%- 50% glycerin in food quality can be
added as an antifreeze to the biocide at preservation (glycol is not permitted as
antifreeze). The plant has to be drained (filter housings, pumps, hoses). Remove filter
cartrid
g
es.
Instruction for mothballing.
Wa
r
nin
g
!
Make sure that you follow the following instructions carefully so that no cleaning
chemical gets into your fresh water tank.
Note!
HP- Pump always pressureless!!! (Pressure control valve (5) open).
The only application with working pressure is the production of product water.
1) Close the sea water intake valve.
2) The pressure control valve must be open. Turn the product water three-way valve (no. 2) to position test-
outlet to avoid that chemicals get into the drinking water tank.
3) Rinse the system with fresh water as described in “Fresh water flushing”.
4) Turn the three-way valve (no. 4) according to the flow diagram “Long term preservation (mothballing) of
the plant”. Open valve (no.1).
5) Dissolve the stated amount of biocide (no. 3) completely in 10 litres of water and pour it into the tank for
conservation. (To avoid negative pressure, do not close the cap tightly) As a result of the water already
in the system, (each pre-filter= 1 litre, each membrane= 1.5 litres) together with these 10 litres, the result
will now be the maximum permitted concentration of 0.5% by weight. A level teaspoon corresponds
to 5 grams Biocide (Natriummetabisulfit).
6) Switch on the feed pump and the high-pressure pump. Let the Biocide circulate through the system for
about 2-3 minutes. Perform possibly exiting the test outlet liquid back into the preservative tank.
7) The Biocide in the tank can be discharged overboard after turning the three-way valve (no. 4). It should
be noted that the s
y
stem
g
ets no air. Switch pumps off.
Amount of biocide DD 500 max. 37 gr. Biocide
Note!
For preservation times of approx. 2 months, half of the chemical is sufficient.