Principle of Operation
A Q-VAC priming system operates automatically to establish and
maintain a prime on all connected pumps. This is accomplished by
piping a vacuum line from the Q-VAC system to a priming valve
installed in the suction piping and housing of each pump. The
differential pressure created by the priming system draws water up
the suction line, lifting it into each pump. As air is removed, and
the vacuum level increases, the water level will rise until the pump
is fully flooded and the float-actuated priming valve closes. Should
the water level drop at any time, the priming valve will open and
vacuum within the air receiver will immediately restore the water
level to ensure that the prime is never lost.
It is important to note that during automatic operation the priming
system operates independently from the pumps being served and will
cycle on only when needed to maintain a preset vacuum range.
To provide verification that a pump is primed and ready to run, a
proof-of-prime level switch, installed in the priming valve,
provides a signal that can be connected to the pumpís motor
controller or used to actuate a prime status indicator light.
In the unlikely event that a priming valve fails and water begins to
flood the priming system, a high water level switch, installed in
the air receiver, will active the alarm circuit and shut the priming
system off to prevent system damage. To allow remote monitoring of
certain alarm conditions, dry alarm contacts are standard within the
Q-VAC control panel.
A Q-VAC priming system will increase water pump efficiency by
removing entrained air while eliminating the possibility of a pump
becoming air bound. Automatic operation of a Q-VAC priming system
ensures that every connected pump is always primed.