Fristam Pumps FPH 3542 User manual

Task Instructions for Seal Replacement - Fristam FPH 3542
Disassembly (with double mechanical seal)
Model FPH3542 with double mechanical seal. Remove cover nuts with 1” wrench.
Remove flat washers.
Remove cover.
Remove the two water pipes from either side of the pump housing. Loosen the four
guard screws and remove two plastic shaft guards from either side of the pump bearing
block.
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Place a chain wrench on the pump shaft near the coupling to keep the shaft from rotating
while loosening the impeller nut with a 15/16” socket wrench. Remove the impeller nut
and impeller gasket.
Remove the impeller from the pump shaft. Use impeller pullers to assist in removing the
impeller, as needed. Be careful not to damage the threads on the end of the pump shaft.
Remove gasket from back of the impeller, if it sticks to impeller. This gasket may stay
positioned in the groove of the seal driver. Remove impeller key from the pump shaft.
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Remove the rotating seal assembly which includes the impeller gasket, seal driver,
rotating seal, seal spring, and rotating seal o-ring. To remove this assembly from the
shaft, place the impeller pullers on both sides of the assembly and pull toward the end of
the pump shaft. Be careful not to drop this assembly as the seal face could be damaged.
Remove seal driver from the rotating seal. Remove the seal driver o-ring from the shaft,
then remove gapping spacer from the shaft. Do not discard the gapping spacer as it will
be reused during reassembly.
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To remove the stationary seal and the flush seal components, the pump housing needs to
be removed. Remove the four pump housing bolts and lock washers, which attaches the
pump housing to the bearing block, using a 3/4” wrench. Carefully slide the pump
housing off the end of the pump shaft, ensuring that the stationary seals (which are
mounted in the pump housing) do not contact the pump shaft.
Place the pump housing on its hub. Remove the stationary seal by placing your fingers
on the ID of the stationary seal and pulling it toward the front of the housing. The
stationary seal o-ring should come out with the stationary seal.
To remove the flush seal components, turn the housing over and place it on the housing
studs. Remove the four retaining ring bolts on the housing with a 7/16” wrench. Remove
the retaining ring, stationary water seal and flat gasket from the housing.
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Now remove the rotating water flush components from the pump shaft, which include the
rotating water seal ring, the water seal o-ring, the water seal spring and the water seal
drive ring. The water seal driver may be left on the shaft.
The above pictures show the components of the rotating water flush seal assembly. Note
that the o-ring fits inside of the rotating seal ring. The longer tabs of the water seal drive
ring fit into the slots on the outside of the rotating seal.
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Task Instructions for Seal Replacement - Fristam FPH 3542
Assembly
You are now ready to install the new seal and reassemble the pump head.
Note: when installing the new seal components make sure that you use all of the
components supplied with the replacement seal kit. Using some of the old components
may reduce seal life.
Slide the water seal drive ring onto the pump shaft with the shorter tabs facing the water
seal driver. Align the short tabs with the slots in the seal driver. Slide the new seal
spring onto the pump shaft and position it against the seal drive ring. Lubricate the new
water seal o-ring with a food grade lubricant. Place the o-ring inside the rotating water
seal ring and slide the assembly onto the pump shaft. Align the tabs in the water seal
drive ring with the slots in the water seal ring. With the pump housing sitting on the
housing studs, place the new stationary seal flat gasket on the shoulder inside the hub of
the housing. Place the new ceramic water seal insert into the back of the housing, over
the flat gasket.
Replace the retaining ring onto the hub of the housing and install the four retaining ring
bolts. Tighten with the 7/16” wrench to 4.5 ft.-lbs.
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Turn the housing over and place it on the housing hub. Lubricate the stationary seal
o-ring and place it on the new stationary seal. Place the stationary seal and o-ring into the
bottom of the pump housing. Align the notch in the stationary seal with the pin in the
housing. Press the stationary seal into the housing until it snaps into place. Wipe the seal
face clean with a soft cloth to remove any oil or grit.
Carefully slide the pump housing over the pump shaft and push it against the bearing
block, ensuring that the stationary seals (which are mounted in the pump housing) do not
contact the shaft. Note: the stationary seals may be damaged if they make hard contact
with the pump shaft.
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Check the rear water seal assembly and make sure the short tabs of the water seal drive
ring are positioned in the slots of the water seal driver. Install the four pump housing
bolts with lock washers through the bearing block into the pump housing. Tighten them
with the 3/4” wrench to 55 ft.-lbs.
Place the new rotating seal spring into the rotating seal between the pins and the front
seal face. Lubricate the new rotating seal o-ring and place it inside the rotating seal.
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Align the pins on the rotating seal with the grooves on the seal driver and press the two
components together. Wipe the seal face clean with a clean, soft cloth. Slide the gapping
spacer onto the pump shaft. Note: it is important to use the same gapping spacer that
was removed, as this is unique to your pump. This gapping spacer is what established the
proper gap behind the impeller when the pump was assembled at Fristam.
Lubricate the new seal driver o-ring and place it on the shoulder in front of the rotating
seal. Note: This o-ring can alternately be placed on the pump shaft, up against the
gapping spacer.
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Slide the rotating seal assembly onto the shaft so the face of the rotating seal meets the
face of the stationary seal.
Lubricate the impeller gasket and place it into the groove on the seal driver. This gasket
seals on the back side of the impeller. Place the impeller key into the shaft keyway.
Slide the impeller onto the pump shaft. Lubricate the impeller gasket and place in the
groove of the impeller nut. Thread the impeller nut with gasket onto the shaft.
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Place the chain wrench on the shaft near the coupling to keep the shaft from rotating
while tightening the impeller nut with the 15/16” socket wrench. Tighten to 40 ft.-lbs.
The picture at the right shows the pump serial number stamped on the side of the cover.
Align this serial number with the matching serial number that is stamped on the pump
housing when assembling the cover to the housing.
Place a new cover gasket on the pump cover. Note: you may need to stretch the cover
gasket so that it fits more easily on the cover. The cover gasket needs to be ordered
separately from the seal kit.
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Install the cover onto the pump housing. Note: Align the serial numbers on the cover
and housing. Place the flat washers and thread the cover nuts onto the housing studs.
Tighten the cover nuts to 45 ft.-lbs. using a cross-tightening technique.
Remove the chain wrench and rotate the impeller shaft to ensure the impeller moves
freely. If it does not, recheck your assembly to make sure that gaskets aren’t pinched and
everything is seated properly.
Replace the two water pipes and the two plastic shaft guards with four guard screws.
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