EBARA EFQU4 - Manual (Page 34)

EBARA Fluid Handling 33
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 (24) was removed for
replacement, carefully center it on the back cover
and secure it with the hardware (27 and 28). The
wear plate must be concentric to prevent binding
when the back cover is installed.
Replace the back cover O-ring (29), 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 (36) 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 (30) 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
Fluid Handling.
Install the bearing housing and seal plate O-rings
and lubricate them with light grease. Ease the
rotating assembly into the pump casing using the
installation tool. Be careful no to damage the O-
rings.
Install the four screw sets of rotating assembly
adjusting screw (22) using the same thickness as
previously removed. Secure the rotating assembly
to the pump casing with the hardware (20 and 21).
Do not fully tighten the capscrew 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 (43), 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 (43), and position the check valve
adaptor in the mounting slot in the suction flange
(44). Align the adaptor with the flange hole, and
secure the assembly with the check valve pin (03).