12
Geberit Drainage Systems
Characteristics and chemical resistance
2.
1
Chemical resistance – The significance of pH values
One of the most crucial factors in selecting a material
for a drainage installation is the chemical loading of the
effluent being discharged.
Effluent with a low or high pH is harmful because of its
corrosive effects, e.g. some drain cleaning fluids have a
pH value of up to 12.
Therefore in order to select the most suitable material
to handle a specific discharge it is important not only
to know the pH value of the effluent but the chemical
resistance of the pipe materials.
For full details see chemical resistance tables in the
appendix to this guide to assess the performance of
Geberit HDPE at various temperatures.
The pH value is therefore important in assessing the
chemical level as it will indicate whether the effluent is
acid, neutral or alkaline. The pH scale ranges from 0 to 14
(see table below).
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
increasingly acid
NEUTRAL
very acid
very alkaline
slightly
acid
slightly
alkaline
increasingly alkaline
HDPE
… can be used safely with pH values from 0 to 14.
… is suitable, for example, for use with effluents
containing over 30% hydrochloric acid.
pH values of some drinks and cleaning agents
pH-value
Cola drinks
2.8
Apple juice
3.5
Tartaric acid
2.2
Citric acid
2.8
Washing solutions
9 -13
Toilet cleaner
2 - 4
