Connecting The Plunger; Packing; Plungers; Disc Valve Systems And Abrasion Resistant Valve Construction - Pentair MYERS APLEX Series Installation And Service Manual

CONNECTING THE PLUNGER

Install the metal baffle plate on the extension rod
and roll the pump slowly until the extension rod male
threads just touch the mating plunger female threads.
Applying a pipe wrench to plunger knurled area,
thoroughly tighten the connection. Do not use a
"cheater" when connecting plunger to extension rod.

PACKING

Packing life for aramid fiber packing may be improved
in some applications by regular, systematic lubrication.
An optional force feed lubricator assembly is often
recommended especially for pumps on continuous
duty. This provides regular, controlled supply of
lubricant lowering friction and heat.
Additionally, the regular application of the correct
lubricant aids dissolving of salt and gyp tending
to build up on the plungers in produced water
applications. For this service, Rock Drill Lubricant is a
popular and effective packing lubricant.
Plungers in CO , ethane, or other very cold liquid
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services may use brake fluid. This fluid does not
congeal into a solid which cannot enter the packing.
Consider the use of an air-sealed cradle into which
dry (instrument) air may be directed, excluding the
moisture which causes plunger icing especially in very
humid conditions.
Packing lubricant for pumps on light hydrocarbons,
hot water, lean oil, naphtha, or gasoline often requires
experimentation.
A good start is to use steam cylinder oil. Castor oil
is sometimes successful as a packing lubrication
for liquid propane and butane services, at ambient
temperature.
In pumps placed in arctic service, a special low pour
point oil is indicated.
Packing lubrication is not permitted on some services,
such as amine, food stuffs, etc., and other packing
styles and materials may be required.

PLUNGERS

Myers Aplex Series offers its own unique product:
the Myers Aplex Series Rokide
premier quality plunger consists of a chromium-oxide
deposition on a solid stainless steel body.
Avoid striking the coated surface (black) during
installation. Apply light forces only on the ends of the
plunger. Do not hammer or pry.
All threads on plungers must be clean and oiled
before assembly. Apply oil to the threads and the
rubbing surface.
plunger. This
®
Myers Aplex Series can supply solid ceramic plungers
on order. This plunger is very fragile, vulnerable to
thermal and mechanical shock, and must be handled
with the greatest care. Use only a rubber mallet to
insert it into the packing. Other plunger types are
available upon request.
DISC VALVE SYSTEMS AND ABRASION
RESISTANT VALVE CONSTRUCTION

GENERAL

Myers Aplex Series has developed a unique system
permitting quick, easy and safe methods of installing
and removing tapered seat valves.
The system allows servicing without distortion of the
seat, with minimum effort and no damage to fluid end
tapers or seat.

SETTING THE VALVE SEAT

Effective pressure-sealing between tapered (male) seat
and tapered (female) fluid end deck is possible only
if the tapers are absolutely clean and dry just prior to
installation.
Examine the cleaned fluid end deck tapers and remove
all deposits of gyp, salt, or other incrustation. Using
emery cloth, lightly rub out any minor imperfections
found in the deck taper.
The puller stem and puller head are provided with
tapered (locking) threads. Screw them together, then
screw the valve seat onto the puller head by hand until
it shoulders against the puller shoulder. Do not tighten.
Lower the seat and puller assembly into the fluid end,
squarely setting the seat into the deck. Then pound the
top of the stem until a sharp metallic sound is heard.
Unscrew the head and stem from the seat.
INSTALLING O-RINGS, ABRASION RESISTANT
SPRING AND CAGE
Install nitrile O-ring over the threaded section of the
seat and position it at the bottom of the threads. Install
the polyurethane insert into the valve. The insert may
be heated in hot water to make it flexible enough to
stretch over the valve. Position the valve into the seat.
Install the valve spring. Apply anti-seizing lubricant to
the threads of the valve cage and screw the cage on to
the threaded valve seat with cage setting tool.
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