Hydrotech PURA ABuv 6_8_12 - Manual (Page 7)

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Figure 1C
flow restrictor
Countdown Timer Assembly
Clamps
Disinfection Procedure
UV disinfection is a physical disinfection process and does not add any potentially harmful chemicals to the water. As UV
does not provide a disinfection residual, it is imperative that the entire distribution system located after the UV be chemically
disinfected to ensure that the water is free from any bacteriological contaminants. The disinfection process must be per-
formed immediately after the UV unit is installed and repeated thereafter whenever the UV is shut down for service, without
power, or inoperative for any reason. The procedure for sanitizing the plumbing system is readily accomplished as follows:
1. Shut off the upstream water supply that feeds water into the reactor chamber and depressurize water system. Remove
the pre-filter cartridge and fill the sump with 1-2 cups of household (5.25%) bleach (chlorine) - Do NOT use hydrogen
peroxide. At all times during the process, make sure the UV unit (and lamp) is turned on and operational!
2. Repressurize water system, open each faucet and allow cold water to run until you smell chlorine, shut the faucet off and
then repeat the process for each faucet, including hot water. You must ensure that all taps, including outside faucets,
dishwashers, shower heads, washing machines, connections to refrigerators, toilets, etc., pass chlorinated water.
3. Once all the locations have passed the chlorine disinfection solution, you will need to leave the solution sit for a period
of 20 - 30 minutes. Reinstall the pre-filter cartridge into the filter and then flush the chlorine solution from the system until
no chlorine smell is detectable. Make sure that each fixture that was disinfected in step 2 is completely flushed of the
chlorine solution as the consumption of this water is not advised due to the extremely high concentration of chlorine. It is
important to remember that in the event that a UV is briefly shut down for routine cleaning or during power interruptions
where water could have passed through the system, the aforementioned procedure must also be followed.
Note A: The addition of chlorine (bleach) to a hot water tank that has in the past been fed with untreated raw water with
high levels of other contaminants (iron, manganese, hydrogen sulphide, organics, etc.) will result in oxidation of these
contaminants and may require repeated flushing of the hot water tank. This contingency must be dealt with indepen-
dently under the startup procedure for any other conditioners that may form a part of the pre-treatment for the UV unit.
Note B: The above procedure (Steps 1 to 3) will result in a massive chlorine residual far in excess of the 0.5 to 1.0 mg/L
typically present in municipally chlorinated water and of a magnitude consistent with the minimum 50 mg/L chlorine
solution recommended for the disinfection of distribution systems known to be contaminated. Do not consume water
until complete system has been flushed.
Figure 1D
Drip Loop