EBARA EFQT3 - Manual (Page 34)

EBARA Fluid Handling 34
Install the bearing housing and seal plate O-
rings (27 and 28) and lubricate them with
light grease. Ease the rotating assembly into
the pump casing using the installation tool.
Be careful not to damage the O-rings.
Install the four screw sets of rotating
assembly adjusting screw (15) using the
same thickness as previously removed.
Secure the rotating assembly to the pump
casing with the hardware (13 and 14). Do
not fully tighten the cap screw until the back
cover has been set.
A clearance of .010 to .020 inch (0.25 to
0.51mm) between the impeller and the wear
plate is also recommended for maximum
pump efficiency. This clearance can be
obtained by adjust an equal of screw from
each rotating assembly screw set until the
impeller scrapes against the wear plate
when the shaft is turned. After the impeller
scrapes, adjust approximately .015 inch
(0.4mm) of clearance with the screw set.
NOTE
An alternate method of adjusting this
clearance is to reach through the suction
port with a feeler gauge and measure the
gap. Adjust rotating assembly screw
accordingly.
Suction Check Valve Installation
(Figure 1)
Inspect the check valve assembly (11), and
replace it if badly worn.
NOTE
The check valve assembly must be
replaced as a complete unit. Individual
parts are not sold separately.
Reach through the back cover opening with
the check valve (11), and position the check
valve adaptor in the mounting slot in the
suction flange (3). Align the adaptor with the
flange hole, and secure the assembly with
the check valve pin (32).
NOTE
If the suction or discharge flanges were
removed, replace the respective gaskets,
apply ‘Permatex Aviation No 3 Form-A-
Gasket or equivalent compound to the
mating surfaces, and secure them to the
pump casing with the attaching
hardware.
Back cover Installation
(Figure 1)
If the wear plate (16) was removed for
replacement, carefully center it on the back cover
and secure it with the hardware (19 and 20). The
wear plate must be concentric to prevent binding
when the back cover is installed.
Replace the back cover O-ring (18), and
lubricate it with a generous amount of No.2
grease. Clean any scale or debris from the
contacting surfaces in the pump casing that
might interfere or prevent a good seal with
the back cover. Slide the back cover
assembly into the pump casing. Be sure the
wear plate does not bind against the
impeller.
NOTE
To ease future disassembly, apply a film
of grease or Never-Seez on the back
cover shoulder, or any surface which
contacts the pump casing. This action
will reduce rust and scale build-up.
Secure the back cover assembly by
tightening the hand nuts (21) evenly. Do not
over-tighten the hand nuts; they should be
just tight enough to ensure a good seal at
the back cover shoulder. Be sure the wear
plate does not bind against the casing.
PRESSURE RELIEF VALVE MAINTENANCE
(Figure 1)
The back cover is equipped with a pressure
relief valve (27) to provide additional safety for
the pump and operator (refer to Liquid
Temperature And Overheating in OPERATION).
It is recommended that the pressure relief valve
assembly be replaced at each overhaul, or any
time the pump overheats and activates the valve.
Never replace this valve with a substitute which
has not been specified or provided by EBARA.