Flowserve MPT - Manual (Page 22)

MPT USER INSTRUCTIONS ENGLISH 85392699 06-09
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6.5.5 Bearings
Bearings generally MUST NOT BE reused after
removal from any shaft; however, due to the small
interference fit of the bearings in these pumps, if
they are removed carefully by pulling on the inner
ring only without the use of heat and if thorough
cleaning and inspection shows them fit for further
service, they may be reused. It is strongly
recommended, however, that they be replaced as a
matter of course. Thoroughly clean the inside of
the bearing housing, bearing cover, and seal
housing, removing any sign of contamination or
rust and dry out with lint-free cloths or dry air.
6.5.6 Suction flange and flap valve
Check the valve seating on the suction flange for
erosion damage and the flap valve for deterioration
of the neoprene sealing surface and replace if
necessary.
6.5.7 Mechanical seal
Carefully inspect seal faces for cracks, chips, or
scoring and O-rings for any obvious damage. If in
doubt either replace or return seal to Flowserve
service center for inspection.
6.6 Assembly
6.6.1 To assemble the pump consult the
sectional drawings.
6.6.2 Prepare
Ensure all parts are on hand; clean and fit for
further service. Pay particular attention to threads
and gasket and O-ring sealing faces. Lightly apply
anti-seize compound to all threads and close fitting
surfaces. Do not unwrap bearings and seals or
expose the bearing housing and seal chamber
inner surfaces until time to fit. Immediately prior to
assembly, wipe clean with lint-free cloth.
6.6.3 Bearings
•
Carefully press the bearings onto the shaft,
applying load to inner ring only; ensure bearings
are pushed hard up against the location
shoulder on the shaft. It is not necessary to use
heat to fit MPT bearings as only light press fits
are involved. If desired, bearings can be heated
to approx. 100 °C (212 °F) with an induction
heater, but under no circumstances use a flame
on the bearings. Fit the circlip [6544] to the shaft
at the outboard bearing [3041]. Note that a
circlip is fitted on all pump sizes except the
MODEL 80
•
Support shaft/bearing assembly on clean vee
blocks under the bearings and check shaft
runout at coupling end and mechanical seal
area. Runout is not to exceed 0.05 mm (0.002
in.) TIR
•
Push shaft/bearing assembly into bearing
housing from drive end, ensuring that thrust
bearing bottoms against shoulder in bearing
housing and that shaft rotates freely
•
Fit new lip seal [4300] into bearing cover [3260].
Note orientation of lip seal (spring loaded lip
faces toward coupling)
•
Fit new gasket at bearing housing face and refit
cover; ensure that seal lip is lightly oiled and
care is taken easing it over shaft shoulder. Refit
and tighten cover fasteners. Check that shaft
rotates freely
6.6.4 Mechanical seal
•
Fit mechanical stationary face holder in recess
at inboard end of bearing cover and fit
stationary face. Take extreme care to keep face
clean and prevent damage. Lightly oil seal
rotating assembly and carefully slide over shaft
to seat against stationary
•
Fit inboard stationary face holder in recess in
seal chamber and carefully fit stationary face
•
Fit new O-ring to recess in bearing housing
joint, fit seal chamber over end of shaft, and
locate on bearing housing spigot. Refit and
tighten fasteners
6.6.5 Impeller
•
Lightly coat shaft and impeller threads with anti-
seize. Preventing shaft from rotating, screw
impeller onto shaft and bottom firmly against
shaft shoulder. Fit and tighten impeller setscrew
[2913] complete with washer [2905-0]
•
Check impeller to seal housing axial clearance,
which should be within the range 0.05/1.35 mm
(0.002/ 0.053 in.) on a new assembly
6.6.6 Suction flange
•
Refit valve flap to suction flange with check
valve pin [6570-4] and nylon washer [2905-1]
•
Fit suction flange to casing with new gasket
[4510-1]
6.6.7 Coverplate/wear plate
•
Refit new, re-machined, or reversed wear plate
[1915] to the cover plate [1223-0]
•
Fit new O-ring [4610-2] to cover and lightly oil
•
Fit cover into casing and retain with hand nuts
[6580-1]