110116.04
5
Rigid waste water tanks for black water, bulkhead mounted
Introduction
These instructions apply to the Vetus rigid plastic waste water
tanks (bulkhead mounted) for
black water
.
Black water tank
A
black water tank
is used only for temporary collecting
toilet waste.
A black water tank should be installed in accordance
with the Recreational Craft Directive (RCD), ISO 8099
Standard.
The capacity of a waste water tank can never be too great.
The capacity should be calculated using the amount of flush-
ing water (outside water) used by the toilet. Reckon on 7 to
14 litres of black water per person per day.
Use only water-soluble toilet paper to prevent unnecessary
blockages. N.B: Sanitary towels and tampons in the toilet
and black water tank will certainly cause blockages.
Clearing a blockage is an unpleasant job, make sure you have a
pair of rubber gloves on board.
Smell
Black water tank
Unpleasant smells caused by faeces will be produced in
every blackwater tank. The use of
sea
water for flushing
will increase the smell. The algae in sea water also produce
unpleasant smells.
It is possible to add special additives to waste water tanks
to reduce the smell, called tank deodorants. A simple way of
reducing the smell is by using washing soda, which cleans and
sterilizes.
Leaking hoses,hose fittings, tanks, tank covers, etc., can also
cause a smell nuisance. So carry out a regular check of the
whole system.
For dimensions, see drawing on page 20. Tolerances of +/- 2%
apply to all tank dimensions!
Use
Emptying
Always empty the tank in accordance with environ-
mental regulations.
There are some regions where direct discharges into
the outside water are forbidden.
The longer waste water remains in the tank, the greater the risk
of smell. SO do not leave a waste water tank full unnecessarily,
but empty the tank on a daily basis, or whenever it is possible.
Emptying the tank:
- A ‘pump-out’ system on the jetty is connected to the tank
cap. This will empty the tank out.
When the tank is pumped empty by a high capacity pump, there
is a risk of the tank collapsing due to the under-pressure. This
problem occurs especially with ‘pump-out systems’.In order to
prevent the tank collapsing, one of the following measures can
be taken:
- Open the tank inspection cover.
- Open a valve specially fitted in the tank for this purpose.
- Install an automatic relief valve.
Emptying the tank while sailing:
- Open the valve while sailing. Make sure the hull outlet is
below the waterline (sailing boats when heeling)
- Maintain a reasonable speed to prevent odour nuisance.
- Close the valve after emptying.
During your absence
Flush the toilet several times to ensure the hose linking the toilet
and the tank is filled with clean water to avoid smells when not
in use.
Clean and sterilize the tank and pipes at least once a year, pref-
erably at the end of the season.
Cleaning
Black water tank
Clean the inside of the tank with water and a good toilet
cleaner, use household vinegar when there are scale depos-
its. Use a brush or sponge on a rigid tank. Rinse the tank with
clean tap water.
Sterilizing
Sterilize the tank by filling with a solution of chlorine bleach
in water (1 : 1000). Allow this solution to circulate through the
waste water system. Remove the solution and rinse tank with
clean tap water.
ENGLISH
