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INSTALLATION
CENTRAL HEATING
Automatic Bypass Valve
Some low water content boilers require greater flow rates than the heating load
of the property requires. Please check your boiler manufacturer’s instructions for
requirements.
The system bypass will enable this minimum flow rate to be achieved. The 22mm
straight bypass fitted to the SP-PP version has a maximum rating of 30kW. It is
adjustable between 0.05 Bar and 0.5 Bar. Has a maximum working pressure of 16 Bar
and intermittent working temperature of 120°C.
The valve manufacturer recommends that most domestic situations will be set
between 0.2>0.3 Bar. If the flow is too high increase the pressure setting and conversely
if too low decrease the pressure setting.
The bypass valve must be set by the installer to suit the system i.e. to provide minimum
flow required for the boiler when all TRVs are closed, and/or when all the zone valves
are closed. Benefits include reduced system noise, reduced pump impeller wear and
enhanced boiler heat exchanger life.
Using the Pump curves in the previous section and the minimum flow from the boiler
manufacturer’s instructions determine the available pump head at the selected pump
speed. Project these values on the chart below to get the valve set point.
e.g For minimum flow 500 l/h and differential Pressure 200 mbar, set the valve at 0.25
Summary of Contents for BOILERMATE OV PP
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