Cashco 3700 - Manual (Page 4)

4 IOM-3700
Tank or system protection is the primary function
of the weight loaded Pressure and/or Vacuum
Relief Vents. As a safety device it is very important
that maintenance/inspection be done on a
regular interval, this includes Emergency Vents.
Maintenance should only be done by a qualifi ed
technician. Valve Concepts recommends that all
service be performed at the factory or a factory
authorized repair center. For information on repair
centers in your area, please contact factory.
Any maintenance requires that the ERV be removed
to a work area for dissassembly. Use an overhead
hoist and cables to lift unit and place on a fl at work
surface.
Rotate nut (7) counter clock wise to remove nut and
strap (29). Use over head hoist and cables - attach
to lift eye (43) and carefully lift pallet assembly and
weights off seat ring (3) and place on a fl at work
surface.
Diaphragm Inspection / Replacement: -
Rotate lift eye (43) counter clockwise and remove.
Rotate upper nut (23) counter clockwise to remove
nut and strap (29). Remove lower nut (23) and
washer (24). (May need to use wrench to hold
center bolt (10) from underneath the retaining plate.)
NOTE: When lower nut is removed, the center bolt
(10) may fall out of the retaining plate (6).
Remove loading weights (18) that may be stacked
on the pallet (4). NOTE: Maintain stack orientation,
do not remove or add any weight that will change the
factory calibrated pressure setpoint.
Lift the weather hood (17) up and remove.
Remove stiffener plate (42), pallet (4) and
diaphragm(s) (5). NOTE: Pressure set point
will dictate the quantity and stack orientation of
diaphragms. Record diaphragm’s stack orientation
for re-assembly. _________________________
Clean and inspect pallet (4) and diaphragm retaining
plate (6).
Position diaphragm retainer plate (6) on a fl at work
surface and lay new diaphragm(s) (5) onto the top of
the diaphragm retaining plate.
Apply TFE paste around hole in the center of the
pallet (4) and lay the pallet onto the diaphragm (5),
aligning the center center holes.
Place the stiffener plate (42) and weather hood (17)
onto the pallet aligning the center holes.
Position the stack of loading weights (18) on top of
the weather hood, again align the center holes.
Slide fl at washer (24) onto centerbolt (10). Apply
TFE paste around fl at washer and insert cap screw/
washer up through the hole in the diaphragm retainer
plate, diaphragms, pallet, stiffener plate and loading
weight(s).
Thread lower nut (23) onto threads of center bolt and
tighten with wrench. Place one end of cable strap
(29) onto nut. Thread another nut (23) followed by
the lift eye onto the threads of the center bolt and
tighten with wrench.
Inspect and clean seat ring (3). Use a Scotch-Brite
pad fi rst and then a clean cloth with Easy Clean
sprayed on it. Check seat surface for any nicks,
corrosion, pitting or product build up. Seat surfaces
must be clean and smooth for vent to perform
properly.
Use an overhead hoist and cables to lift the pallet
assembly (4) onto seat ring (3) with eye lift (43)
upwards.
Place other end of strap (29) over stud (30) and
secure with nut (7).
Return to Section IV for installation.
SECTION V
V. MAINTENANCE: