HIGH PERFORMANCE BUTTERFLY VALVES - MODEL SLHBF & SLHBFFS
Australian Pipeline Valve - Installation, Operation and Maintenance Manual
19
6.7 SEAT RING REPLACEMENT
If fluid can’t be shut-off under the full closing position of disc, then seat damage is suspected. In the case
of seat damage, replacement should be carried out as follows:
a. Refer to 6.4 for instructions on disassembly of seat ring/seat retainer.
b. Replace the damaged seat ring with a new one.
c. New seat ring should be seated to matching angle of the disc profile (i.e. usually 10~15° of disc opening
angle).
d. For re-assembling of the seat retainer, reverse the steps of the previous disassembly.
e. Slightly tighten the seat retainer bolts up to the closing position.
f. Rotate the disc a couple of times and then tighten the bolt completely with the 10~15° of disc-opening
angle.
g. Finally, rotate the disc several times to ensure the correct position of the seat. The above needs to be
done to get the seat settled in position.
h. Install the valve on the pipeline with disc fully closed.
Note
Over tightening of bolts may cause damage to bolts or valve. Studs should be
lubricated prior to installation. Bolt tensions shown in table 1 must be decreased by
25% when no lubrication used. Non lubricated bolts can have an efficiency of up to
50% less than the torque of values stated.
DIAGRAM 9
Retainer Bolts
Seat Retainer
Seat Ring
Slightly tighten bolts
Completely tighten bolts
Turn the Disc
Close Position
Turn the Disc
10~15 degree to open.
Turn the Disc
10~15 degree to open.
Indicative drawing only, design will vary according to size, class, end connections, trim, seating type, etc.
