SANDPIPER M02 Metallic - Manual (Page 8)

520-263-000 5/03 Model M02 Metallic Design Level 1 Page 7
SERVICE
NOTE: Before commencing any
service or maintenance work on the
pump, ensure that the air supply has
been disconnected or isolated.
AIR VALVE SYSTEMS
PNEUMATIC TYPE
Remove the 4 screws securing the valve
body to the intermediate bracket, together
with any associated gaskets or seals.
Remove slide valve plate & slide valve
from the valve body assembly. Clean all
parts thoroughly and inspect for excessive
wear, replacing where necessary.
The slide valve and valve plate contact
faces should be flat and free from
scratches. a light polishing on a flat
surface with a fine abrasive paper will
remove most scratches.
If excessive wear is suspected in the valve
body bore or valve carrier, remove the end
caps and withdraw the valve carrier.
Check valve block plug o-rings for wear or
attack & replace where required.
Clean the valve carrier & valve body bore
with white spirits to remove any oil films.
NOTE: The nominal diametrical
clearance between the valve carrier
and the valve body bore should be
0.05 - 0.09mm. A clearance in excess
of this will cause the valve system to
run erratically.
Apply a light grease to the end cap o-rings
when re-assemblling into the valve body
bore. any damage to the o-ring may cause
the valve system to malfunction.
Re-assemble the valve body asembly &
re-torque in accordance to the settings
shown in the parts list.
In the event of a complete air-side over-
haul, the pump should be disassembled
down to the center section assembly
as described later in the "Wet-Side
Overhaul" section.
With the valve body assembly dis-
mantled, remove the inner covers where
appropriate.
A careful note of the position of all
related seals and gaskets should be
made to facilitate re-assembly.
Remove diaphragm rod bushings where
appropriate, and check all seals and
o-rings for wear or damage. If worn,
replace immediately.
NOTE: The integrity of the diaphragm
rod seals is essential for the correct
functioning of all pneumatically
actuated valve systems.
Check the diaphragm rod for excessive
wear as this will result in premature seal
failure. Replace as required. Lubricate
all components and re-assemble as
detailed above, in reverse order. Ensure
the correct position of all components
detailed in all sectional assembly
drawings.
WET-SIDE OVERHAUL
REPLACING BALL VALVES
Remove discharge mainfold from pump
assembly together with associated valve
balls, seats and o-rings.
NOTE: The orientation of the valve
seat relative to the valve ball should
be noted as incorrect positioning
may result in a performance loss.
Turn pump through 180o and remove
the suction manifold. Clean and inspect
the components. Check for any wear
or damage and replace as required.
NOTE: Ball or valve seat wear may
result in loss of performance and
suction lift.
Re-assemble the valve balls/seat and
ensure manifolds are adequately torqued
to the settings shown in the parts list.
REPLACING DIAPHRAGMS
Remove both suction and discharge
manifolds as detailed in the previous
section, removing all ball valves, seats
and o-rings.
Loosen and remove both outer chambers
from the pump assembly. The orientation
of the covers should be noted so as to
facilitate re-assembly.
Holding one of the other diaphragm
plates in a vice, ("soft jaws" should be
fitted), or with an adjustable spanner,
loosen and remove the outer diaphragm
plate from the opposite end. Remove
the inner diaphragm plate and bumpstop
from diaphragm rod.
Carefully withdraw the diaphragm rod
from the intermediate bracket and hold
the free end in a vice, holding between
the flats machined on the end. Loosen
and remove the outer diaphragm and
remove the diaphragm together with
inner diaphragm plate and bumpstop.
NOTE: Care should be taken with all
plastic, coated and hygienic pumps,
so that the surface of the outer
diaphragm plate is not damaged.
Thoroughly clean all parts and check
for wear, damage, swelling, cracking,
delamination and chemical attack.
Replace components where required.
NOTE: Rubber diaphragms should
be replaced if they are worn to such
an extent that the fabric re-enforcing
is evident on the surface of the
diaphragm.
For pumps fitted with PTFE diaphragms,
a light coating of grease should be
applied to the back-up diaphragm prior
to re-assembly.
Before re-assemblly, it is advisable to
check the condition of the diaphragm
rod seal/o-rings for wear or attack. If
either is evident, it is recommended
that they be replaced.
Assemble the diaphragms onto the rod
in a reverse sequence to their removal.
Care should be taken as to the orienta-
tion of the diaphragm relative to the
front and back plates. All diaphragms
have "AIR SIDE" moulded onto one
side. The inner diaphragm plate must be
fitted adjacent to the "AIR SIDE" of the
diaphragm.
WARNING
For repairs, use only genuine
Marathon spare parts.
Failure to do so may immediately
invalidate any warranty claims.