Introduction
This manual is for the Vetus (rigid) plastic waste water tanks (for 'gray water' and 'black water'). See the drawings on page 28 for
dimensions. Tolerances of + or - 2% apply to all dimensions!
These tanks are made from low pressure polythene and therefore have the following properties: they are algae resistant, hardly any
condensation is formed, the material is insulating, the surface is very smooth, the plastic is indestructible and very environmentally friendly
and there are no electrolysis problems.
Use
Emptying
The longer polluted water has been in the tank the greater the
risk of nuisance from smell. Therefore, never leave a waste water
tank filled unnecessarily long, but pump the tank empty or have
it pumped empty once a week, or whenever possible. Pumping
empty can be done in two ways:
- by connecting a shore pump-out system to the deck cap to
pump the tank empty.
- by using a pump present on the ship to pump out the waste
water through the deck cap and a hose connected to this.
This pump must have internal diameter of minimum dia. 38 mm
(1½ inch).
If the tank is pumped empty by a high capacity pump there is
a risk of the tank collapsing due to the reduced pressure caused.
This problem occurs particularly when using the pump-out
systems. The following measures can be taken to prevent collapsing
from occurring:
- open the inspection cover on the tank
- open a shut-off valve fitted to the tank for this purpose
- install an automatically working blow valve.
During your absence
The water in the siphons can evaporate when no use is made of
washbasins, showers etc. for a long time (siphons act as smell
traps in the pipes). This causes smell nuisance. Therefore, place
plugs in all drains when the ship is not to be manned for a longer
period.
Disinfect the tank and pipes at least once a year preferably at the
end of the sailing season.
Cleaning
'Gray water' tank
Clean the inside of the tank with water and a good degreasing
household cleaner; use a brush or a sponge for a rigid tank.
Rinse the tank with clean tap water.
'Black water' tank
Clean the inside of the tank with water and a good toilet cleaner;
add cleaning vinegar if there are lime deposits; use a brush or a
sponge for a rigid tank. Rinse the tank with clean tap water.
Disinfecting
Disinfect the tank by filling it with a solution of bleach in water
(1: 1000). Circulate this disinfecting mixture through the waste
water system. Remove the solution and rinse the tank with clean
tap water.
'Gray water' tank
A 'gray' water tank is only to be used for collecting water
from a sink, shower, washbasin, air conditioning, etc. and not for
toilet waste. The capacity of a waste water tank can never be
too large. Choose the capacity of the tank to suit the quantity of
fresh water, that is the capacity of the water tank(s). Fit a drain
with a sieve to the sink, shower, washbasin etc, so that as little
as possible coarse waste such as hairs and similar can collect
in the tank.
'Black water' tank
A 'black' water tank is to be used exclusively for the temporary
collection of toilet waste. In order to comply with the European
Recreational Craft Directive it must be possible to see the quantity
of "black water" in the tank from outside of this or a float
must be fitted that is connected to an indicator positioned in an
easily accessible place. A "black water" tank must be installed
in accordance with the European Recreational Craft Directive
(ERCD), standard ISO 8099.
The capacity of a waste water tank can never be too large, and
must be geared to the quantity of water used (external water)
to flush the toilet. Allow for 7 to 14 liters (2 to 4 Gallon) of black
water per person per day.
Only use toilet paper that will dissolve in water in order to prevent
unnecessary blockages from occurring. N.B. Sanitary towels in
the toilet or "black water" tank will inevitably result in blockages!
Solving blockages is an unpleasant task. Make sure that you
have a pair of rubber work gloves or surgeon's gloves on
board.
Smell
'Gray water' tank
Unpleasant smells are produced in all 'gray water' tanks. Fit the
sink, shower, washbasin etc. with a siphon (smell trap) and a
plug.
'Black water' tank
Unpleasant smells are produced from the feces in all 'black water'
tanks. The amount of smell produced is increased by the use
of salt water for flushing (because of the algae present in salt
water). Special substances, so-called tank deodorants, can be
added to a waste water tank if necessary to reduce the smell. A
simple way of reducing the smell is to use soda that both cleans
and disinfects. Leaking hoses, hose fittings, tanks, tank cover
etc. can also be the cause of smell nuisance. Therefore, carry
out regular checks of the complete system.
Installation
General
Take the following into account when choosing a position for the
tank and the deck filler cap: the filler hose must be as short as
possible, must slope down continuously from the deck cap to
the tank and must be as straight as possible. There must be
sufficient ventilation in the space in which the tank is positioned.
The height difference between the tank and the filler cap may
a maximum of 2 metres (6'8") (the maximum excess pressure
in the tank is 0.2 bar (3 psi) !)
Positioning
Position the tank in such a
way that it is readily accessible
for inspection. Also make
sure that there is sufficient
free space above the tank
for the hose connections.
These must be easily accessible
during fitting. There
must be free space with no
bulkheads or other tanks of
about 1 cm ( 3/8" ) all round
the tank to allow ventilation.
Ensure that there is a sufficiently
solid foundation for
placing and fixing the tank
firmly.
The size of a tank increases
slightly when it is full.
Take this into account when
fixing the tank in place.
Fitting in sailing ships
When fitting remember that the filler
hose must always be positioned
on the same side of the ship as the
tank.
This prevents too high a pressure
from possibly occurring in the tank
when sailing at an angle.
Connecting the tank
Use good quality hose to connect the tank. Avoid sharp kinks or
sagging in the hose when doing this.
Support the hose with brackets at regular distances not too far
apart. Sediment will collect where the hose sags and can lead to
blockages after a time.
The reinforced hose must be a smell-proof waste water hose and
at least resistant to a small increased or reduced pressure of 0.3
bar (0.3 kgf/cm2) (4,2 psi).
Vetus supplies a hose that is suitable for waste water. Use a good quality stainless steel hose
clamp for all hose connections.
Install the pump '13' and the hull lead-through with shut-off
valve '15'.
Install the suction hose(s) '21' and/or '22' dia. ( 38 mm) (1½") in
such a way that neither the tank, the pump nor the deck cap is
mechanically stressed.
Fit the vent nipple '18' as high as possible, above the level of
the top of the tank. Choose a suitable place for the vent nipple
so that rain or water from outside cannot penetrate. If desired fit
a smell filter '19' between the vent pipe and the vent nipple.
Fit the vent pipe '23' internal diameter 19 mm (¾"), between
the vent nipple and the tank.
The vent pipe must be fitted so that it is continuously sloping
upwards as seen from the tank.
Suction pump
A non-self-priming waste water pump must be positioned lower
than or at the same height as the bottom of the tank. A self-priming
waste water tank may be positioned at any height relative
to the tank.
Install the bend aerator '14', in the discharge pipe between
the pump and the hull lead-through, if the waste water tank is
positioned below the waterline and the hull lead-through is also
below the waterline.
Rinsing pipe
In order to be able to rinse out the tank easily with clean water
an extra fitting can be made in the top of the tank that can be
connected to an extra deck cap through which clean water can
be added.
Fit a discharge hose A, internal diameter 38 mm ( 1½" ), between
the deck cap (5) and the tank. Install this hose so that
neither the tank nor the deck cap is mechanically stressed. Take
the maximum excess pressure of 0.2 bar (3 psi) into account;
i.e. the filler cap may not be fitted more than 2 meters
(6' 8") higher than the tank.
Fit the vent nipple 1 as high as possible above the level of the top
of the tank. Choose a suitable place for the vent nipple so that
rain or water from outside cannot penetrate.
Fit the vent pipe B, internal diameter 19 mm, between the vent
nipple (1) and the tank connection (2). It is very advisable to fit
a smell filter type NSF19 in the pipe. This prevents unpleasant
smells from the vent nipple.
The vent pipe must be fitted so that it is continuously sloping
upwards as seen from the tank.
Making ready for winter
The tank, pipes, pump etc. must always be drained completely.
Never put anti-freeze in the tank or other parts of the drinking
water system to protect it against freezing, anti-freeze is very
poisonous!
Maintenance
Check the vent nipple regularly and clean the sieve of the vent
nipple if necessary. Check the hoses and hose connections for
possible leaks annually and fit new hoses and/or hose clamps
as necessary.
Also check the tank for damage as a result of chafing. Replace a
damaged tank immediately.
Carry out the disinfection procedures described under 'Use' at
the beginning of the sailing season; see page 6. A tank and installation
that is strongly contaminated by algae can be cleaned
by rinsing the tank, the pump and pipes with chlorine water.
It is advisable to grease the seal with Vaseline on both sides at
every service.
Scope of delivery
- 1 rigid waste water tank (40, 60 or 80 l)
- fitting connection dia. 19 mm ( ¾ ") for vent hose
- suction pipe with fitting connection for dia. 38 mm (1½") hose
- inspection cover with counter ring
- 2 fixing belts
- fitting spanner
Technical details
Material of suction pipe: |
Pa 6 |
Right-angled fittings: |
360° rotating |
Capacity: |
40 l (8,8 Imp.gal, 10,6 US.gal), |
|
60 l (13,2 Imp. gal,15,9 US gal), |
|
88 l (19,4 Imp. gal, 23,2 US gal) |
Wall thickness of tanks: |
7 mm ± 1.5 mm (¼ " ± 1/16") |
Material of tanks: |
LLDPE |
(Linear Low Density Polyethylene) foodstuffs quality
Maximum permitted pressure: 1.2 bar (17 psi)
Properties of LLDPE:
algae resistant
hardly any condensation (important for fuel tanks)
insulating material, very smooth surface
indestructible plastic
most environmentally-friendly plastic
has no electrolysis problems unlike stainless steel
Dimensions of fittings:
Suction hose: dia. 12 mm ( ½ ")
Vent hose: dia. 19 mm ( ¾ ")
Filler hose: dia. to be determined by user
(i.e. dia.16 (5/8 ") , 19 ( ¾ ") , 25 (1 "), 35 (1 3/8") or 38 mm (1½")
|