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SYSTEMSURE WATER ANALYSIS TEST KIT
The test kit enables engineers to make an immediate
determination of the quality of water in a heating system,
enabling them to understand the causes of problems, and
to select the appropriate treatment to prevent future
system failures and call backs.
The tests will indicate whether a system has been
properly pre-commission cleaned, if corrosion is either
taking place or is likely to occur, if the system should be
power flushed, and whether it has been treated with the
correct level of inhibitor.
The kit comprises six tests:
pH (acidity / alkalinity)
The pH of the water is an indication of how acid or
alkaline it is. The scale runs from 0 (acid) through
7 (neutral) to 14 (alkaline).
Corrosion rates in ferrous metals and copper increase
rapidly with pH below 6, or above 9.5.
Aluminium heat exchangers and radiators are affected if
the pH is below 6, or above 8.5.
Dissolved iron
A test reading of just 1 mg/l above that of the mains
water is an indication that corrosion is already taking
place (even though water drawn from the top of a
radiator may appear clear).
After flushing a dissolved iron level check can ensure that
all flushing chemical has been removed. If chemical is still
present the level will be higher than the mains water.
Dissolved copper
A level of 1 mg/l or more indicates corrosion problems,
and is associated with excessive use of flux when
installing or repairing the system, indicating an
inadequate pre-commission cleanse.
Only low levels are usually recorded as the copper in
solution tends to plate out onto steel and aluminium
surfaces, causing localised wasting (at ca 0.5 to 1 mg/l),
and pinholing at higher levels (above 1.0 mg/l).
Issue: May 2023
Section F – Power Flushing Accessories
Total hardness
More than 60% of Britain, by area, has water classified as
hard, expressed as more than 200mg/l calcium
carbonate.
The harder the water, the more prone heat exchangers
are to scaling up. Whilst soft water (less than 100mg/l
calcium carbonate) tends to be more corrosive to metals
used in heating systems.
If the hardness in the system water is less than that in the
main water it is probable that scaling has already
occurred. Even if hardness levels are apparently similar
scaling may have occurred if the system has been
frequently drained and refilled, or if a leak has led to the
ingress of fresh water.
Soft water (less than 2 mg/l) produced by a water
softener should not be used in central heating as it is
more aggressive than natural soft water, particularly to
aluminium.
Chloride level
Most mains water supplies contain some chlorides
varying from 20 up to 100 mg/l. Chloride levels
significantly above the mains level (more than
25 mg/l or 50%) can cause pitting and corrosion of mild
steel, particularly in areas of high stress such as bends
and welds, and will reduce the performance of corrosion
inhibitors. High chloride levels are indicative of flux
contamination and the lack of pre-commission cleaning.
Inhibitor concentration
It is important to check the correct level of corrosion
inhibitor in a system to ensure long term protection
against internal corrosion, sludge formation, scale
deposition, and boiler noise.
The Systemsafe-DM test kit is used to check the correct
level of Kamco inhibitor. The test measures the
molybdate content within the system.
The optimum molybdate level for
Systemsafe-DM (0.5% dose) is 100ppm.
If an existing system still contains the original Kamco
Systemsafe-DM at 1% dose then it is 330ppm.
A higher value is not detrimental, but if the test indicates
under-dosing then the level should brought up to the
optimum by the further addition of Systemsafe-DM
(concentrate).
All tests come complete with full instructions.
Page F.16
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