31
Operation:
• To assure tight shut-off, the valve must be
closed using a wrench with 25 to 30 ft-lbs of
torque.
• To assure trouble free check valve operation
and shut-off operation, the valve should be
periodically opened and closed to keep valve seat
and valve disc guide stem free of build up of
system contaminants.
Repacking of Flo-Trex valve under full system
pressure:
• If it is necessary, the stem O ring can be
changed under full system pressure.
Step 1.
Record the valve setting.
Step 2.
Turn the valve stem counterclockwise
until the valve is fully open and will not turn any
further. Torque to a maximum of 45 ft-lbs. This
will ensure good metal to metal contact and
minimal leakage.
Step 3.
The valve bonnet may now be removed.
There may be a slight leakage, as the metal to
metal backseating does not provide a drip-tight
seal.
Step 4.
Clean exposed portion of valve stem
being careful not to leave scratches.
Step 5.
Remove and replace the O ring gasket.
Step 6.
Install the valve bonnet.
Step 7.
Tightening the valve bonnet is necessary
to stop any leaks.
Step 8.
Open valve to balance set point as
recorded in Step 1.
Note: On valve sizes of 2-1/2 inch and 3 inch,
the full open position is 5 turns, though the
valve will open to 5-1/2 turns which is just
back of seating of valve.
Seat Replacement:
Step 1.
Drain the system and remove valve from
piping.
Step 2.
Remove the body bolts from the body
using an Allen Key.
Step 3.
Remove seat and O Ring. O rings are not
used on valves of 8 inches or larger.
Step 4.
Inspect and clean O ring cavity and
install new O ring and seat. Valve disc stem
should be inspected and replaced if worn. Valve
stem O ring should be replaced at this time as
discussed under Repacking of Flo-Trex section.
Pressure-Temperature Limits:
