CHOICE OF DESCALING CHEMICAL
AND QUANTITY REQUIRED:
SCALEBREAKER HD may be
used with mild steel, or copper
equipment. If galvanised steel is
present, then SCALEBREAKER SR,
together with ZnI booster inhibitor,
should be used.
If stainless steel is present, use
either SCALEBREAKER FX or
SCALEBREAKER SR. Do not use
SCALEBREAKER HD with stainless
steel equipment.
1. Calculate the amount of
descaling chemical required. As
a guide, for 30 litres of descaling
solution, use 3 kg SCALEBREAKER
SR crystals, (ie. a 10% solution by
weight). A weaker solution may
be used, but will take longer to
remove a given amount of scale.
Use of warm water will speed up
descaling.
2. In the case of most humidifier
bottles, with a water capacity
of up to 15 litres, use of a C40
descaling pump, which has a 39
litre tank capacity, will allow 30
litres of descaling solution to be
placed directly in the pump tank.
Upon switching on the pump, it
will first fill the capacity of the
humidifier bottle before any
descaling solution commences
returning to the tank of the
descaling pump.
3. If a C20 descaling pump, with
20 litre tank, is used, it wil
be necessary to add further
descaling solution to the pump
tank after switching on, in order
to ensure that enough descaling
solution is present to completely
fill the humidifier bottle, and
also to ensure that the minimum
liquid level in the tank is
achieved.
Caution
When descaling with any
acid, some hydrogen gas may
be evolved. Hydrogen is
flammable, and the working
area should be well ventilated.
Avoid smoking nearby, or any
other means of ignition.
PROCEDURE
1. Remove humidifier bottle
from humidifier and place in
controlled area, away from
other personnel. It is preferable
to ensure that the humidifier
bottle is maintained in an
upright position, in order that
the carbon dioxide gas evolved
during descaling will rise to the
top of the bottle and be vented
through the return pipe of the
descaling pump.
4. Connect one pump hose to water
inlet connection of bottle, and
the other to the water outlet.
Many humidifier bottles have
large diameter tubular inlet and
outlets, and suitable adaptors
terminating in a BSP thread will
have to be fabricated.
5. Hose connections should be
made so that there is a closed
circuit between the pump flow
hose, through the humidifier
bottle, to the return hose.
Venting of the carbon dioxide
gas evolved is achieved through
the tank filling aperture. The
descaling pump filler cap should
be screwed on by no more than
one quarter of a turn. This is
sufficient to vent the gas, but
will reduce fumes and prevent
splashes.
6. Connect the pump to a suitable
earthed power supply. As the
pump will be used in a damp
location, a residual current circuit
Guidance notes on descaling humidifier bottles
