Control Tests

In order to minimise scaling and/or corrosion of these systems, the following control tests must be performed, and all water test results must be documented on a dedicated record sheet (see typical record sheet overleaf):

(a) Log the quantity of water softened/dealkalised between regenerations;

(b) Log the make-up water meter reading at least once per month;

(c) At least once per day on large systems and 3 times per week on small systems, perform the following tests on boiler water samples and log these test results:

(i) neutralised total dissolved solids.... must be 1500-3000 ppm (2000-4000 micromhos/cm);

(ii) phosphate ......................must be 40-80 ppm PO4;

(iii) hydroxide alkalinity.........must be 150-300 ppm CaCO3;

(iv) total alkalinity .................must be less than 700 ppm CaCO3;

(v) sulphite...........................must be 30-60 ppm SO3; (50 ppm Na2 SO3)

(vi) pH ..............................must be 10.5-11.5.

(d) At least once per day on large systems and 3 times per week on small systems, determine and log the pH level of the condensate return—it must be 8.5-9.5 pH for systems that are not used for humidity control and 8.0-8.5 pH for systems that are used for humidity control;

(e) At least once per day on large systems and 3 times per week on small systems, determine and log the TDS concentration of the condensate return—it must be less than 40 ppm (50 micromhos/cm);

(f) At least once per day on large systems and 3 times per week on small systems, determine and log the total hardness concentration of the condensate return & softener effluent—they both must be less than 2 ppm CaCO3;

(g) While performing the above tests, note the general appearance of the water samples—the boiler water samples may be colourless or amber & contain either no sediment or a small amount of sediment, whereas the condensate & softener samples must be clear & colourless with no sediment.

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