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OPERATING PRESSURE AND BACK PRESSURE
Operating pressure is a combination of back pressure plus all of
the other resistances to flow present in your system.
BlackStone Pumps are designed to dose their rated output at the
operating (
rated) pressure.
Therefore,
rated pressure of the pump you install should be close
to operating pressure present in the system.
Too little back pressure can cause the pump to overdose.
To prevent this from happening on a low back pressure installation,
a spring has been added to the discharge/anti-siphon valve
assembly (
HI 721004
).
When pumping into a high back pressure, the spring should be
removed.
ACTUAL FLOW RATE
The actual flow rate depends upon the operating pressure which
includes resistance at the injection fittings, hose and piping, the
chemical viscosity and suction lift. The Flow Rate Control adjusts
the flow up to 100% of the
rated output. Less back pressure will
increase the output, more will decrease it. To determine the correct
setting for your application, use the following procedure.
1. Be sure that the pump is primed and that the output connections
are completed at the injection point.
2. Place the foot valve assembly
(
HI 721005
) in a graduated
container with 500 mL of the
solution to be dosed.
3. Switch the pump from OFF to the
100% setting and run until the
system has been fully reprimed.
Switch OFF and refill the
container to the 500 mL level.
Summary of Contents for BL1.5
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