Pump Solutions Group Neptune Series 500 MODEL 481 THRU 547 User Manual
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FIGURE II
IN METAL HEAD PUMP
FIGURE III
IN PVC HEAD PUMP
ANTI-SIPHON
SPRING
P/N 000257
ANTI-SIPHON
SPRING
P/N 100198
P/N 100199
3.0 DISCHARGE
PIPING
3.0.1
It is recommended that the ‘‘dia-Pump’’ operate against a minimum discharge pressure of 50 psig. A
back pressure spring is supplied loose with the pump. If 50 psig back pressure is not provided by the
application, the back pressure spring should be installed on the pin under the discharge valve cap.
Installation of the back pressure spring artificially creates a discharge head. (Refer to Figures II and
III.) Note: Spring is not provided in 500-E Series.
3.0.2
Take care to use piping suitable for the discharge pressure.
4.0
ADJUSTMENT OF INTERNAL RELIEF VALVE
4.0.1
All Neptune Series 500 dia-Pumps are supplied with an internal relief valve preset to 200 psi.
The internal relief valve is designed to protect the pump itself should a discharge pressure beyond the relief
valve setting occur.
If a customer order specifies a relief valve setting above those indicated above, the specified setting will be
set at the factory. All pumps are tagged with the relief valve setting used by the factory.