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RISER FILTER SCREEN SERVICING
RISER SEAL REPLACEMENT
I
The riser seal on G90 and G95 risers include two primary components - the seal block assembly
and the face-seal. The seal block assembly sits on top of the retraction spring and has two
sealing surfaces. First, the seal block has an O-Ring around the outside. If the O-Ring is damaged,
deteriorated or missing, the riser will leak water while the sprinkler is operating. The second
sealing surface on the seal-block assembly is on the underside. The angled surface on the
underside of the seal-block assembly is the interface for the face-seal. If this angled interface
surface is cut or otherwise damaged, the riser can leak water during sprinkler operation. The
face-seal is the second primary component to the G90 and G95 riser seal design. The face-seal is
the white plastic angled ring that is position at the base of the riser. If the face-seal is damaged,
deteriorated or missing, the riser will leak during sprinkler operation.
If the riser is leaking during sprinkler operation, the O-Ring, the interface and the face-seal must
be inspected in order to determine the cause of the leakage. If the O-Ring is damaged, it can easily
be replaced by removing the damaged O-Ring from the seal-block and replacing it with a new one.
Use care to ensure that the O-Ring is not cut or twisted during the installation process. If the
interface is damaged, the entire seal-block must be replaced. Also, if the interface is damaged it
is highly likely that the face-seal is also damaged and needs replacement.
To replace the face-seal, slide it upwards and off the riser assembly. Replacement face-seals must
fit very snug to the stainless-steel on the riser. As a result, there may be considerable resistance
when attempting to install the new face-seal. To make installation easier, the face-seal’s diameter
can be expanded by placing it in the sun for several minutes. Or, if the repair is being done in the
shop, placing the face-seal in warm water for several minutes will cause expansion as well. Slide
the new face-seal down and onto the riser. Make sure that it is pressed all the way until it is seated
firmly against the ledge at the base of the riser. Install the retraction spring and seal-block assembly
onto the riser. Press down on the seal-block to compress the retraction spring and hold firmly in
this position. While firmly holding the retraction spring and seal assembly down, place the retainer
cap on top of the riser in the correct orientation. Insert the two stainless-steel screws and hand-
tighten with a Phillips screwdriver.
RISER FILTER SCREEN SERVICING –
ALL TTS ROTORS
The riser filter screen is located at the base
(bottom) of each riser. The purpose of the filter
screen is to prevent entry of debris that are too
large to exit the riser through the nozzles. If the
filter becomes clogged with debris, water flow
through the riser can be severely reduced and
lead to diminished sprinkler performance.
To remove the filter screen, locate the notched
recessed area located on the outside where it
meets the bottom of the riser (FIGURE 54, 55,
56). Insert the snap-ring tool or a flat bladed
screwdriver into the recess and then twist to
lift the filter screen from its position against the
riser. Flush filter screen with water to remove
debris. To install filter screen, press firmly into
position against the riser.
Fig 51
Fig 52
Fig 51
Fig 52
Fig 51
Fig 52
FIGURE 51
FIGURE 52
FIGURE 53
FIGURE 54
FIGURE 55
FIGURE 56
