Pump Solutions Group Neptune Series 500 MODEL 481 THRU 547 - Manual (Page 19)

16
SYMPTOMS CAUSES REMEDIES
L. No foot valve strainer. L. Install one.
*3. Pump delivers erratically. A. Leaky suction line. A. Repair or replace piping.
B. Worn or dirty valves or seats, or
both. B. Clean or replace cartridges.
C. Excessive excursion of ball from
valve seats (indicated by ball
chatter).
C. Replace cartridges.
D. Liquid too close to boiling point. D. Reduce temperature or raise
suction pressure.
E. Leaky internal or external relief
valve.
E. Repair or replace relief valve.
4. Motor Overheats Thermal
Overload Activates
A. Overload caused by operating
pump beyond rated capacity.
A. Check operating pressure against
pump manufacturer’s data plate
maximum rating.
5. Noisy Operation
(1) In Pump A. Pump Valves. A. Valves must move to open and
close, and they will make a clicking
noise as they operate. These
noises are sometimes amplified by
natural resonances in piping
system. They are usually
indications of normal valve
functioning.
(2) In Gear Reducer A. Pounding noise at high discharge
pressure.
A. Fluid compressibility causes
reversal of load on gears at end of
pressure stroke. Not considered
detrimental.
6. Improper Oil Level in
Reservoir.
A. Increases and overflows. A. Flexible diaphragm punctured by
foreign material – replace
diaphragm. Clean and flush
hydraulic system at once.
7. Pump Delivery is Not
Adjustable
A. System pressure too low. A. Install back-pressure spring,
provided, into discharge cartridge.
B. Install Back-pressure valve.
8. Pump Does Not Develop
Required Pressure
A. Internal relief valve leaking. A. Check setting as per pressure
change procedure, Paragraph 4.0.
B. Internal relief valve being
actuated.
B. System pressure exceeds relief
valve set pressure.
Refer to Paragraph 4.0 for
adjustment procedure.
* Symptoms 2 and 3 ---- A Diaphragm may need replacing.