MHS Boilers Ultramax 115, Operating & Maintenance Manual, Page: 30 / 46

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The chloride concentration must not exceed 200 mg/l
. If this level is exceeded, the cause must be
located. Compare the chloride concentration of the additional water with that of the system water.
If this concentration is higher, this indicates evaporation if no chloride containing materials have
been added. If chloride is present in high concentrations the water will be more aggressive (due
to, among other things, incorrectly regeneration of the water softener). The system must then be
flushed out and re-filled with low chloride content water.
To reduce the effects of unnecessary wear and blockages resulting from any pollution present we
advise the use of a filter system with a mesh opening of 100 microns. Always fit this in the return
pipe of the secondary part of the system.
In order to guarantee a well functioning system and a long life, any suspended and corrosion
producing particles must be removed with the aid of a well chosen and fitted filter system.
The analysis of system water and the cleaning of filters must form part of the periodic inspection
procedure.
It is imperative that the system is treated with suitable corrosion and scale inhibitors. The
concentration of the dosage must be monitored and maintained on a regular basis. Failure to comply
with these requirements will render the appliance warranty null and void.
5.4.6 Examples of hydraulic systems
The hydraulic systems shown are only examples. They must not be employed in practice without
professional analysis.
Low velocity header
The low velocity header must be dimensioned such that at full capacity the pressure difference
between the supply to the flow and the return collector does not exceed 50 mmwg (approximately
0.5 m/s). The diameter of the low velocity header can be determined using the formula:
Where:
= the diameter of the low velocity header in mm
Q = the water flow rate in m
3
/h of the boiler circuit or the secondary circuit, whichever is the greater
v = the s peed in m/s.