Condensate Drainage And Neutralizing - Viessmann Vitocrossal 300 CT3 Technical Manual

2.10 Condensate drainage and neutralizing

2.10 Condensate drainage and neutralizing
The acid condensate formed both in the
condensing boiler and in the flue pipe
must be discharged into the public drain
age system in accordance with the regula
tions. A condensate is produced with pH
values between 3 and 4 with gas-fired sys
tems.
Neutralization of the condensate dis
charged into the public drainage system
is generally not required in the case of
gas-fired condensing boilers up to
200 kW rated output.
Planning notes on condensate drainage
The condensate discharge outlet to the
drainage system connection should be
clearly visible. It must be installed with a
suitable gradient, provided with a stench
trap and equipped with suitable devices
for taking samples. The bottom drain
must be below the reflux level of the flue
gas collector.
Only corrosion-resistant materials should
be used for condensate drainage pur
poses (e.g. braided hose). Furthermore,
galvanized materials or materials contain
ing copper must not be used for pipes,
couplings etc.
The condensate drain must be provided
with a trap to prevent the flue gases from
escaping.
Neutralizing equipment
Suitably matched neutralizing units are
available for Vitocrossal 300 condensing
boilers:
26
Gas-fired systems over 200 kW
Neutralization of the condensate from
these systems is generally required. On
leaving the Vitocrossal 300, this conden
sate is neutralized by means of a neutra
lizing agent in the neutralizing unit/sys
tem. This treatment raises the pH value to
between 6.5 and 9.
The composition of the treated conden
sate is suitable for disposal via the public
sewage system. The neutralizing agent is
gradually consumed by the condensate.
It must be noted that domestic drainage
systems must be constructed from ma
terials which are resistant to acid conden
sate:
These materials are as follows:
H Stoneware pipes
H Rigid PVC pipes
H PVC pipes
H Polyethylene (PE-HD) pipes
H Polypropylene (PP) pipes
H Acrylonitrile (ABS/ASA) pipes
H Stainless steel pipes
H Borosilicate glass pipes
H Granulate neutralizing unit for boilers
up to 460 kW
H Granulate neutralizing system with lifting
pump and granulate refill indicator for
boilers with 575 to 895 kW.
As the rate of consumption depends on
the pattern of operation of the system,
regular checks must be made during the
first year of operation to establish the
quantities of neutralizing agent and the
frequency with which these need to be
added. The actual consumption can be
established through observation over a
long period.
It is advisable to contact the department
of the local authority responsible for
waste water issues well before commenc
ing with the installation of the system in
order to establish details of local regula
tions which apply.
See technical data sheet "Boiler acces
sories" for technical data on the neutraliz
ing units and accessories.