Oil Scoop; Wiper Box Assembly; General; Poly Pak" Seal - Pentair MYERS APLEX Series Installation And Service Manual

for these initial loadings, maintained by hardened
spring lockwashers.
After all rods and caps are secured, slowly turn the
crankshaft to be sure no bearing is in a bind.
Examine the location of each connecting rod (eye
end) within its crosshead. Rods must not touch any
crosshead boss or skirt.

OIL SCOOP

These pumps also employ oil scoops which are cast
integrally with the power frame and are machined to
lightly contact the crankshaft cheek. No adjustment
is required.

WIPER BOX ASSEMBLY

GENERAL

Extension rod wiper boxes serve two important
functions: retention of crankcase oil in the power end
and exclusion of dirt and water.
Myers Aplex Series has developed a unique sealing set
which operates on a hardened and ground stainless
steel extension rod (often called "pony" rod) and a
rubber baffle disc, affording protection against leaking
plunger packing. The seals require no adjustment, only
correct and careful assembly.

"POLY PAK" SEAL

This seal keeps oil from leaking out of the power frame.
Developed by the Parker Seal Group, this patented rod
seal employs a soft nitrile rubber O-ring to energize a
special hard polyurethane Molythane
the inner lip against the rod and the outer lip against
the housing bore, as shown.
The Poly Pak seal is inserted into its counter bore with
its lips directed toward the oil in the crankcase.

MECHANICAL OIL SEAL

The oil seal is to keep contamination out of the power
frame. With the box positioned in a hydraulic press,
install the backup seal against the Poly Pak seal, with
the lips of both seals facing downward.
The mechanical seal contains a garter spring. Check
to see that this spring is still properly located and in
its position. The mechanical seal has a metal case
which serves to force the "Poly Pak" seal into its cavity,
energizing its lips. Apply oil lightly to the bore of the
box before pressing each seal into its counte rbore.
shell by forcing
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INSERTING THE EXTENSION ROD

Insert the extension rod through the wiper seals with
the tapered thread and entering first. Care should be
used in moving the extension rod through the seals
with wrenching flats entering first. The sharp corners on
the wrenching flats may damage the seal lips.
With extension rod inserted through the wiper box
seals, thread the tapered threads into the tapered
crosshead female threads. Firmly tighten, apply
torque to the wrenching flats only. Never damage the
extension rod ground surfaces!
Then fasten the wiper box to the power frame by
tightening the cap screws. Oil leakage between frame
face and wiper box is prevented by use of an O-ring.
STUFFING BOX, PACKING AND
PLUNGER ASSEMBLIES
GENERAL
Myers Aplex Series pumps all feature field removable
and replaceable stuffing boxes with plungers separable
from the extension rods.
If desired, the boxes, plungers, and packing units may
be installed (or removed) as a unit assembly, permitting
service outside the pump. All boxes are retained by
studs and nuts, and are centered in the frame bore,
ensuring correct alignment.
The plungers may also be removed separately (without
box removal) to facilitate repacking. With this option,
the necessary space required to remove plunger, it is
first necessary to remove the extension rod.
SPRING LOADED PACKING
Note that the gland is screwed tightly onto the box
and contacts its face. The spring is providing all of the
initial compression and adjustment. No adjustment is
provided by the gland.
Since the force exerted by the spring is contingent on
the space provided for it, the correct lengths of all rings
are essential for good tensioning.
Spring:
An Inconel spring, which closely fits the bore of the
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stuffing box, is used in this assembly. This spring is
compressed in a vise to the operating length required
plus 0.25" and tied with waxed nylon spot tie cord. The
cord is looped over the ends of the spring through the
coils and tied to maintain the length mentioned above.
Each spring is assembled into the stuffing box. Note
that the spring does not contact the plunger.