De Nora Capital Controls 71V3B Series, Instruction Manual

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4 MAINTENANCE

It is mandatory that the Vaporizer be shut down at least once a year for cleaning and inspection of the vaporizing  

chamber. This requirement is based on the recommendation of the Chlorine Institute, Inc. for Chlorine service. 

However, State and Local Regulatory Agencies should be consulted to make certain this recommendation conforms 

to their minimum requirements. In all cases, it is recommended that the Vaporizer be disassembled, cleaned and 

inspected when the heater Duty Cycle reaches 90%. This situation indicates a loss of evaporation ability possibly due 

to deposit build-up in the evaporating chamber or the water jacket.

A preventative maintenance kit, P/N 22257, is available from the factory. The kit contains 2-Immersion Heater  

Gaskets, 4-Magnesium Anodes, 4-Anode Grommets, 1-Chamber Gasket and a Service Record Tag.

The heater on/off cycle times may be determined using a stopwatch or equivalent and the heater Duty Cycle is  

calculated as follows:

    On Time + Off Time   =   Total Time

    Duty Cycle   =   On Time 

   Total Time

The low water level switch should be checked for proper operation at least once a year by lowering the water level in 

the Vaporizer. Be certain to turn on the make-up water and that the Vaporizer is operating normally after performing 

this test.

NOTE

During disassembly and cleaning, inspect all parts thoroughly and replace any worn or damaged parts.  

When a part which comes into contact with either the liquid or gaseous chemical needs replacement,  

it is mandatory that the new part be made of materials which will withstand the corrosive action  

of the chemical being handled. 

Therefore, only De Nora Water Technologies parts, manufactured from materials selected for their  

proper corrosion-resistant properties, must be used. When ordering parts, always furnish the  

complete model and serial number of the Vaporizer, and the chemical being used. 

Refer to Figure 3 and the exploded views shown in Section 6 to supplement the following text. Additionally, if the 

Vaporizer is located indoors, turn on the exhaust fan and open the doors and windows to provide the maximum 

ventilation possible. This is especially necessary during the steam cleaning portion of this procedure since the fumes 

emitted from the non-volatile residue are noxious and may at times be nauseous.
  1) Shut down the Vaporizer as described in Section 3.11.

  2) Lift and remove front and back covers.

  3) Remove eight screws and the reinforcing strip located at the back top edge of the cabinet.

  4) Remove the four top panel screws and top panel attached to the side panels.

  5) Remove four screws securing side panels to mounting brackets and remove side panels. (Two screws per panel.)

  6) Disconnect the removable pipe section which interconnects the liquid chemical supply line to the Vaporizer  

    inlet connections.

CAUTION

Chlorine or Sulfur Dioxide will combine with water (even the moisture in air) to form a  

very corrosive acid. When any piping section is opened or disconnected for servicing, the opening  

must be sealed immediately. This also applies when changing chemical containers.

7) 

Connect a supply of compressed air to the Vaporizer inlet connection, unlock and open the vent blow-off valve, 

and turn on the air to purge the vaporizing chamber free of all residual vapors emitted from the accumulated 

deposits of non-volatile residue. Then turn off and disconnect the air supply, close the vent blow-off valve, 

and disconnect the removable pipe section which interconnects the Vaporizer outlet connection to the gas 

discharge line.