Gorman-Rupp Pumps SFV4C 1474143 and up - Manual (Page 43)

SF SERIES OM-06403
MAINTENANCE AND REPAIR PAGE E - 18
the upper seal stationary seat, resulting in
seal leakage.
Seal and Motor Cavity Testing
Connect the vacuum pump or compressor/venturi
system to the pump as shown in Figure E-4.
If the compressor/venturi cannot draw the higher
vacuum level shown in Table E-1, draw the motor
cavity vacuum down as far as the system will allow,
then draw the seal cavity down so the differential
between the two cavities is the same as the differ­
ential between the vacuum readings shown in the
table.
To vacuum test the motor cavity, the terminal hous­
ing assembly must be replaced with a test plate.
Make the test plate as shown in Figure E-5 below,
install the terminal housing O‐ring under the test
plate, then proceed with vacuum testing.
.438” (11,1 mm) dia. drill
thru. Tap .250‐18 NPT.
12 mm dia. drill thru (4) holes
equally spaced on a 4.72 (120 mm)
diameter bolt circle.
Install terminal
housing O‐ring
for test.
3.749 - 3.750 in
(95,22 - 95,25 mm)
1.5 in.
(38,1 mm)
.75 in.
(19,1 mm)
5.5 in.
(139,7 mm)
Make from commercially available steel plate.
45 _ x 1/8” (3,1 mm)
Chamfer
Figure E-5. Motor Vacuum Test Plate
Install full‐closing ball‐type shutoff valves with
quick‐disconnect fittings in the pipe plug holes in
both the motor and seal cavities. Test the motor
cavity for its full duration first, then use the shutoff
valve to maintain the motor cavity vacuum while
testing the seal cavity. The motor cavity vacuum
must be higher than the vacuum in the seal cavity
to prevent separation of the seal faces or unseating
the stationary seal seat between the seal and mo­
tor cavities. Figure E-4 shows a simple schematic for setting
up either a vacuum pump or a venturi/compressor
test system.
Table E-1 shows the vacuum to be drawn on each
cavity, and the duration to maintain each vacuum
reading. Any change in vacuum reading during
the test indicates a leak which must be identified
and corrected before putting the pump back into
service.
Table E-1. Vacuum Test Data
Seal Cavity
Vacuum
(In. Hg.)
Motor Cavity
Vacuum
(In. Hg.)
Duration
(Minutes)
Duration
(Minutes)
20 3 30 1
LUBRICATION
Seal Cavity
Check the oil level in the seal cavity before initial
startup, after the first two weeks of operation, and
every month thereafter.
Check the oil level only when the pump
is cool. If the oil level plug is removed
when the pump is hot, pressure in the
seal cavity can cause hot oil to be
ejected as the plug is removed.