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SETTING THE VALVE SEAT
PULLER STEM
PUMP FLUID END
PULLER HEAD
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. Thoroughly clean surfaces using a clean
solvent. Dry with a CLEAN shop towel.
Examine the cleaned fluid end deck tapers, using a
flashlight, 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 using
two pipe wrenches applied to the knurled areas
provided. 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 with a 6 pound hammer until a solid
metalic sound is heard, usually 2 or 3 blows.
Unscrew the head and stem from the seat using a 1/2"
bar (or screwdriver) into the hole provided at the top
end of the stem.
INSTALLING DISC, SPRING,
DISC VALVES AND STEM
Aurora Pump, Aplex Series offers discs of Delrin
acetal resin, of 17-4PH S.S. hardened and ground, and
of titanium alloy.
INSERT 1/2" BAR TO
UNSCREW HEAD
FROM SEAT
DISCHARGE
VALVE DECK
SUCTION VALVE
SEAT
®
20
Position the disc and Inconel
aligning the hole in the disc with the stem threads in
the seat center.
The stem, spring retainer, and locknut are shipped
from Aurora Pump, Aplex Series already assembled and
tightened with a torque wrench with Loctite
added to the top stem threads only.
Stem Threads
1/2"-13UNC
Use an anti-seizing lubricant in these threads. This
is very necessary when seats and stems of Type 316
stainless steel are selected (optional) to prevent
galling. CLEANLINESS of threads and other contacting
surfaces is of paramount importance in the assembly of
all valve elements.
VALVE SPRING OPTIONS
All Aurora Pump, Aplex Series valve springs are made
of Inconel
material, precisely designed and fabricated.
®
Unless otherwise specified, the standard spring is
furnished. It provides excellent results in the great
majority of applications.
Pumps employed in marginally available NPSH
conditions may require a "softer" spring, to reduce the
required NPSH. For these special conditions, Aurora
Pump, Aplex Series can supply light valve springs
which exert lower pressure on the valve disc. The use
of light valve springs may be limited by the choice
of plunger size and/or limited by the chosen speed
of the pump. Light valve springs may be impractical
for pump models fitted with their maximum plunger
size, or which operate near top speed rating as disc
bouncing and erratic seating may occur.
VALVE DISC OPTIONS
Aurora Pump, Aplex Series acetal resin discs made
of DuPont Delrin
are machined flat and smooth to
®
produce perfect sealing on the lapped-flat face of the
seat. Used successfully in thousands of applications,
these discs are light, slightly flexible under load, and
seal well, even at high pump speeds, providing smooth
pump action.
Acetal resins are very resistant to most corrodents,
but are not usually suitable where fluid temperatures
are above 120 degrees. Nor do they afford long life
at extreme pressures. Pressure limitations depend on
valve size. But continuous valve operation at pressures
above 2,500 psi usually indicates the need of metal
valve discs.
For higher temperatures or pressures, Aurora Pump,
Aplex Series offers lapped flat, hardened Type 17-4PH
spring on the seat,
®
sealant
®
Tightening Torque
65-75 ft. lb.
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