13
H5-991-406A
H/G-25-SD Service (Fluid End)
3. Inspect and Replace
Diaphragms (22)
a...Lift. one. of. the. diaphragms. by. one. edge,. and. turn. the.
pump.shaft.until.the.diaphragm.pulls.up..This.will.expose.
machined.cross-holes.in.the.valve.plunger.shaft.behind.the.
diaphragm.
b...Insert.the.plunger.holder.through.the.top.hole.to.hold.the.
diaphragm.up..The.proper.size.tool.is.included.in.the.Wanner.
Tool.Kit.
c... Remove.the.screw.(19),.O-ring.(0),.and.follower.(1).in.the.
center.of.the.diaphragm.
d...Remove.the.diaphragm.and.inspect.it.carefully..A.ruptured.
diaphragm.generally.indicates.a.pumping.system.problem,.
and.replacing.only.the.diaphragm.will.not.solve.the.larger.
problem..Inspect.the.diaphragm.for.the.following:
.
•.
Half-moon marks
..Usually.caused.by.cavitation.of.the.
pump.(refer.to.“Troubleshooting”).
.
•.
Concentric circular marks
..Usually.caused.by.cavitation.
of.the.pump.(refer.to.“Troubleshooting”).
.
•.
Small puncture
.. Usually. caused. by. a. sharp. foreign.
object.in.the.fluid,.or.by.an.ice.particle.
.
•.
Diaphragm pulled away
.from.the.center.screw.or.from.
the.cylinder.sides..Usually.caused.by.fluid.being.frozen.
in.the.pump,.or.by.overpressurization.of.the.pump.
.
•.
Diaphragm becoming stiff
.and.losing.flexibility..Usually.
caused.by.pumping.a.fluid.that.is.incompatible.with.the.
diaphragm.material.
.
•.
Slice in ridge of diaphragm
..Occurs.when.a.diaphragm.
is.operated.at.temperatures.below.its.rated.capability.
.
•.
Diaphragm edge chewed away
.. Usually. caused. by.
overpressurizing.the.system.
e...Inspect.the.plunger.(3).for.any.rough.surfaces.or.edges..
Do
not
.remove.the.plunger.from.the.valve.plunger.(54)..Smooth.
the.surfaces.and.edges.as.necessary.with.emery.cloth.or.a.
fine.file.
.
Caution: If a diaphragm has ruptured and foreign
material or water has entered the oil reservoir, do not
operate the pump. Check all diaphragms, then flush the
reservoir completely (as outlined below) and refill it with
fresh oil. Never let the pump stand with foreign material
or water in the reservoir, or with the reservoir empty.
f... Install. a. new. diaphragm. (or. reinstall. the. old. one,. as.
appropriate),.ridge.side.out.
g...Clean.and.dry.the.screw.(19),.removing.any.oil.from.it..Apply.
medium-strength. threadlocker. to. the. screw.. Reinstall. the.
screw,.the.follower.(1),.and.a.new.O-ring.(0)..Tighten.to.
18.in.-lbs.(.0.N-m).
h...Repeat.the.above.inspection.procedure.(and.replacement,.
if.necessary).with.the.other.two.diaphragms.
4. Flush Contaminant from
Hydraulic End (only if a
diaphragm has ruptured)
a...Remove. the. oil. drain. cap. (34). and. allow. all. oil. and.
contaminant.to.drain.out.
b...Fill.the.reservoir.with.kerosene.or.solvent,.manually.turn.the.
pump.shaft.to.circulate.the.kerosene,.and.drain.
.
Caution: If you have EPDM diaphragms, or if food grade
oil is in the reservoir, do not use kerosene or solvents.
Instead, flush with the same lubricant that is in the
reservoir. Pumps with EPDM diaphragms have an “E”
as the 7th digit of the Model No.
c... Repeat.the.flushing.procedure.(step.b).
d...Fill.the.reservoir.with.fresh.oil,.manually.turn.the.pump.shaft.
to.circulate.the.oil,.and.drain.once.again.
e...Refill. the. reservoir.. If. the. oil. appears. milky,. there. is. still.
contaminant.in.the.reservoir..Repeat.the.flushing.procedure.
until.the.oil.appears.clean.
5A. Prime the Hydraulic Cells
a...With.the.pump.
horizontal and the fluid-end head removed
,.
fill. the. reservoir. with. the. appropriate. Hydra-Oil. for. the.
application.
b...All. air. in. the. oil. within. the. hydraulic. cell. (behind. the.
diaphragms).must.be.forced.out.by.turning.the.shaft.(and.
thus.pumping.the.piston)..A.shaft.rotator.is.included.in.the.
Wanner.Tool.Kit..Turn.the.shaft.until.a.
bubble-free
.flow.of.
oil.comes.from.behind.all.the.diaphragms..Watch.the.oil.level.
in.the.reservoir;.if.it.gets.too.low.during.priming,.air.will.be.
drawn.into.the.pistons.(inside.the.hydraulic.end).and.will.
cause.the.pump.to.run.rough.
c... Wipe.excess.oil.from.the.cylinder.casting.and.diaphragms.
5B. Priming the Hydraulic Cells
for Kel-Cell Pumps
NOTE: Providing oil prime to Kel-Cell fitted pumps requires
pressure be applied to the diaphragms. This can be
done manually, with the system head pressure, or with
pressurized air if available. Review all methods below to
determine the procedure most suitable.