13
G5-991-400A
H/G-25 Service (Fluid End)
3. Inspect and Replace
Diaphragms (22)
.
a...Lift. the. diaphragm. 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.an.Allen.wrench.through.one.of.the.holes,.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.the.“Troubleshooting”.section).
. .
•. Concentric circular marks.. Usually. caused. by.
cavitation.of.the.pump.(refer.to.the.“Troubleshooting”.
section).
. .
•. 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.
. .
•. diaphragm.is.operated.at.temperatures.below.its.rated.
capability.
. .
•. Diaphragm edge chewed away..Usually.caused.by.
overpressurizing.the.system.
.
f.. 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.
.
g.. Install. a. new. diaphragm. (or. reinstall. the. old. one,. as.
appropriate),.ridge.side.out.
.
h...Clean.the.screw.(19).and.remove.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).
.
i... 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 on
Standard Pumps
.
a...With. the. pump. horizontal,. and. the. fluid-end. head.
removed,.fill.the.reservoir.with.the.appropriate.Hydra-oil.
for.the.application..Have.a.catch.basin.for.oil.that.leaks.
from.behind.the.diaphragms.when.priming..Catch.the.oil.
and.dispose.of.it.properly;.do not reuse it.
.
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. (4). and.
diaphragms.(0).
.
d...Ensure.that.the.oil.is.1.inch.(5.mm).from.the.top.of.the.
fill.port.
.
e.. Replace.oil.fill.cap.(7).
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.
