27
“At the end of the disinfection of drinking water installations, the used disinfection
solution must be cleared so that no damage to the environment is caused. The
oxidising effect of the disinfectant can be rendered ineffective by adding reducers.
The pH value must also be observed and corrected if necessary.”
An application concentration for the dosing solution for hydrogen peroxide H
/ l and an exposure time of 24 hours are recommended.
15)
n leafl et “Flushing, disinfection and commissioning of drinking
water installations” (August 2014) of the German Central Association for
Sanitary, Heating and Air Conditioning (ZVSHK)
The following must be observed for
: “At the end of disinfection, the entire
system must be fl ushed at all tapping points until the concentration of the disinfectant
at all tapping points measured at the transition point (usually the water meter) is
reached or dropped below again.
To be observed for disposal: “If the water used for disinfection of an installation is to
be drained into a drain pipe or sewer, the responsible department must be informed
and the water may only be drained when the responsible department has granted its
permission.” “Because of the rapid decomposition, the disposal of hydrogen peroxide
by draining into the sewer system is unproblematical.”
A maximum line length of 100 m is specifi ed for fl ushing sections in the European
standard EN 806-4:2010 and in the information leafl et “Flushing, Disinfection and
Commissioning of Drinking Water Installations” (August 2014) of the German Central
Association for Sanitary, Heating and Air Conditioning (ZVSHK). For this length a
volume of approx. 20 l is required for a ½” galvanised steel pipe and a volume of
approx. 100 l disinfectant for a 1 ¼” pipe (see Fig. 6: Volume in l/m of different pipes).
16)
the information leafl et “Leak Tests of Drinking Water Installations
with Compressed Air, Inert Gas or Water” (January 2011) of the German Central
Association for Sanitary, Heating and Air Conditioning (ZVSHK) defi nes the following
for the national regulations under “3.1 General”:
“Due to the compressibility of gases, the rules for the prevention of accidents
“Working on Gas Systems” and the “Technical Rules for Gas Installations DVGW-
TRGI” must be observed for physical and safety reasons when conducting pressure
tests with air Therefore, the test pressures have been defi ned as maximum 0.3
MPa/3 bar/43.5 psi, the same as for load and leak tests for gas pipes, in agreement
with the responsible industrial liability insurance association and based on these
rules. The national regulations are thereby fulfi lled.”
17)
, the information leafl et “Leak Tests of Drinking Water Installations with
Compressed Air, Inert Gas or Water” (January 2011) of the German Central Association
for Sanitary, Heating and Air Conditioning (ZVSHK), the following is defi ned with regard
to the test methods A, B, C for pressure testing with water offered in section 6.1 of EN
806-4:2010: “For reasons of practicability on the building site, a modifi ed method based
on practical tests which can be used for all materials and combinations of materials was
chosen. The test time has been extended in relation to the time specifi ed in the standard
to allow even the slightest leaks to be detected. Test method B in accordance with DIN
EN 806-4 is the basis for conducting the leak test with water for all materials.” The
Leak testing with water can be conducted when
changing of the water can be ensured at regular intervals, after seven days at
the latest, from the time of the leak test to commissioning of the drinking water
installation. Additionally when
it is ensured that the house or building water connection is fl ushed and therefore
released for connection and operation,
the pipe system is fi lled using totally hygienic components,
the system remains full from the leak test to commissioning and partial fi lling can
18)
This rule of the legal German accident insurance must be observed for Germany.
“Operation of work equipment”, BGR 500, April 2008, chap. 2.31, Work on gas
industrial liability insurance association rule.
In addition, for Germany, the technical rule for gas installations
Worksheet G 600 April 2018 DVGW-TRGI 2018”
of the DVGW German Gas and
Water Association defi nes the following among other things:
“5.6.2 Safety measures during the tests”: Safety measures may need to be taken
during the tests when carrying out the load test due to the compressibility of gases.
“The max. test pressure may not exceed the value of 3 bar. Every sudden rise in
pressure in the pipe system to be tested must be avoided.”
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