COMMISSIONING
The valve must be commissioned under normal
site system conditions and after establishing
supply conditions with the hot and cold water
supplies open, leave the system running to
allow temperatures and pressures to stabilise
and be checked.
Prior to commencing commissioning, the
following checks should be carried out.
• Thedesignationofthethermostaticmixing
valve matches the application.
• Thesupplypressuresandtemperaturesare
within the operating range of the valve.
• Isolatingvalvesandstrainersareprovided.
If all these conditions are met, proceed to
set the temperature as described below.
The Prestex thermostatic mixing valve is
supplied factory set at 43°C but the valve may
be simply adjusted after installation.
The mixed water temperature at the
terminal fitting must never exceed 46°C
When the valve has been installed with the
correct conditions of use it is advised that
the valve is subjected to exercise prior to the
commissioning at the application temperature.
Operate the valve from full cold to full hot at
least three times.
With the valve at the full cold position
bring the valve to the correct application
temperature by turning the spanner clockwise.
If the valve overshoots this temperature,
return the valve to the full cold condition,
and reset it to the correct temperature +0-2°C.
Do not set a valve on a lowered temperature as
this will not provide consistent operation.
When the valve is set to the required
temperature for the application carry out 5
cold water isolation tests to further exercise
the valve.
• Setthemixedwatertemperaturetothe
required value. It is advisable to use a
calibrated digital thermometer for checking
the inlet and outlet temperatures.
• Removetheplasticprotectivecapontopof
the valve with a suitable tool.
• Measureandrecordthetemperatureofthe
hot and cold water supplies at the inlets to
the valve.
• Measureandrecordthetemperatureof
the water discharging from the valve at the
greatest draw-off flow rate.
• Intheabsenceofothertemperaturesbeing
specified those detailed in Table 2 are the
desired settings
Once the required mixed outlet temperature
has been achieved, isolate the cold water
supply and monitor and record the mixed water
temperature including the maximum and final
temperatures achieved. The mixed water
temperature should never exceed 46°C.
Re-fit the cap.
Record all the equipment used during
commissioning.
• using a close fitting
spanner, reduce the
mixed outlet
temperature by
turning clockwise.
• increase the mixed
water outlet
temperature by
turning
counterclockwise.
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