Intent 1:
To exempt non-metallic materials from the application
of Sentence 4.5.2.1.(2) if:
- such materials are required for reasons of corrosion,
contamination, or sanitation or standards of purity, and
- certain standards are met.
This is to limit the probability
that:
- internal stress or mechanical damage will lead to failure
of the piping, or
- a chemical reaction with the liquid will lead to premature
corrosion of the piping, which could lead to failure of the piping.
This is to limit the probability of the escape of liquid,
which could lead to the ignition of vapour from a nearby ignition
source, which could lead to harm to persons.