Parker Hannifin Corporation
Gear Pump Division
Kings Mountain, North Carolina USA
17
Recommended
Test Procedure
Make certain that there is an adequate supply of oil
for the pump; at least one gallon of oiI for each gpm of
pump capacity.
If one section of a tandem pump is being tested,
make sure that all other sections not being tested
are adequately supplied with oil. If any of the other
sections run dry, or if plugs are left in ports, serious
and permanent damage will result.
The oil should be a good quality hydraulic oil rated
at 150 SSU at 100° F., with the oil temperature held
at 120° F. plus or minus 50° F. (Test procedures are
described in detail in SAE handbooks; see Hydraulic
Power Pump Test Procedure, SAE J745c.)
The feed line must be of adequate size with no more
than 5” mercury vacuum adjacent to the pump inlet. As
a rule, the feed line must provide a feed flow velocity
not in excess of 8 feet per second.
Feeding hot oil into a cold pump may cause the pump
to seize. Jog the pump by momentarily starting and
stopping repeatedly the driving engine or motor to
gradually equalize pump and oil temperatures.
Run the pump at least two minutes at no load and
moderate speed (not over 1500 rpm). If the pump
becomes excessively hot, shut down immediately and
locate the problem source.
Gradually increase pressure on pump, in 500 psi incre-
ments until the desired test pressure has been reached.
This should take about five minutes.
Delivery should run close to rated catalog performance
figures, which are averaged from testing several pumps.
A 5% lower reading may be used as a rated minimum
if new or relatively new parts have been used. When
rebuilding the pump with parts from the original pump,
which, while worn, appear satisfactory for reuse, a 10%
or 15% lower reading may be
permitted, depending on the performance expected
from the equipment. One’s own experience will prove
the best guide here.
At test speeds other than 1800 rpm, gpm delivery will
vary almost proportionately, but the same (drop-off)
figures should be used.
Be sure to run the pump in the direction for which it
was designed and built. Driving the pump in the wrong
direction will build up pressure behind the shaft seal,
damaging it and necessitating replacement.
After completing testing procedures, the pump is ready
for installation and immediate duty operation
on equipment. Again, it must be remembered that
to prevent seizure, hot oil must not be fed into a
cold pump.
Catalog HY09-SM500/US
Test Procedure
PGP/PGM500 Series
Service Manual
