Pulsafeeder OMNI Series DC7 - Manual (Page 8)

8
5.4 Discharge Pressure Requirements
All OMNI
®
metering pumps are designed for continuous service at the rated discharge pressure.
If system suction pressure exceeds discharge pressure (a condition sometimes described as
“pumping downhill”), flow would be generated (siphoning) in addition to that caused by the
pump. This results in a reduction in accuracy and loss of control over the metering process. To
prevent this flow-through condition, the discharge pressure must exceed suction pressure by at
least 0.35 Bar (5 psi). This can be achieved where necessary by the installation of a
backpressure valve in the discharge line. Conditions where the actual discharge pressure
exceeds the pump’s rating are to be avoided as they will cause damage to the pump
components.
Figure 3, sample system configuration