Multi Display
when an automatic balancing valve is selected
The ProComm unit has the ability to display variables associated with automatic balancing valves. The
valve shown is an externally adjustable type.
If a valve is selected that is not adjustable (either internally or externally), the setting tab is not shown on
the valve image.
The design flow for any automatic flow controller will be achieved if the differential pressure across the
valve reaches the design value. Each automatic balancing valve (and each setting for the valve) will possibly
have a different design DP and the ProComm unit has the ability to hold the design DP for each
valve/setting.
Many of the automatic balancing valves programmed into the ProComm have their actual characteristic in
the database. The level of differential pressure across the valve will determine which data is used.
Generally, with automatic valves there is a slight fall in flow when the DP reaches high values. This fact is
true for most automatic valves but, normally, the fall in flow is within the stated tolerance for the valve.
When the ProComm is adjusted to select the correct valve/setting, the design flow is displayed within the
valve image. If the DP is not sufficient to create correct flow conditions, the box above the inlet pipe to
the valve will display an
up
arrow and a value indicating that the DP will need to be increased to achieve
the design flow. The value displayed is the design DP less the actual DP.
In the event of the actual DP being higher than the design DP, the box will display a
down
arrow and a
DP value that suggests a reduction in actual DP. On an index circuit this would suggest that the pump
speed could be decreased to achieve the correct DP value.
If the design flow is not met, the message LOW FLOW will be displayed. If the design flow is met then the
message displayed is FLOW OK.
10
Crane XXXX
