Flowserve Vogt Forged Steel Gate - Manual (Page 45)

Flow Control
Vogt Valves
FCD VVENIM2000-02 Forged Steel Gate, Globe and Check Valves 45
actuator arm shall be adjusted to cause the close switch to
trip in the closed position. For “spring-to-close” actuators,
the air supply to actuator shall be vented and the spring
allowed to close the valve. The close switch actuator arm
shall be adjusted to cause the switch to trip.
b. Open Switch: Stroke the valve to the fully open position by
application of an air supply for “spring-to-close” actuators.
With the air applied to the actuator, the open limit switch ac-
tuator arm shall be adjusted to cause the open switch to trip
in the fully open position. For “spring-to-open” actuators,
the air supply to actuator shall be vented and the spring al-
lowed to open the valve. The close switch actuator arm shall
be adjusted to cause the switch to trip.
c. Final Cycling: Following the setting of the open and closed
switches, the actuator shall be fully closed and opened to
ensure the limit switches trip as required.
8. System Pressurization Once the system is under pressure,
the stem/actuator coupling nut thread engagement may need
further adjustment. During performance testing at Flowserve,
the stem/coupling nut thread engagement is set to a level to
acceptably pass a seat test of 110 percent of the pressure for
which the actuator was sized. (See #5 above.)
9. Supply Pressure
a CAUTION: The actuator nameplate contains a “Maximum
Air Supply” that should be used. In the event the actuator
is not supplied with a supply air regulator to make this
adjustment, it is the responsibility of the end-user to
provide an air supply regulator. Over-pressurization of
the actuator can damage the unit, requiring major repair.
10. Accessories Accessories for the air actuators shall be sup-
plied with the Installation, Operation and Maintenance Manual
applicable to each unit.
Vogt AOV Valve Maintenance
Recommended Spare Parts
1. Bonnet gasket—See Section 1 for part number. Listed gaskets
are available from Flowserve distribution on short notice.
2. Packing—See Section 1 for part number. Listed packing is avail-
able from Flowserve distribution on short notice.
3. Actuator—See applicable Installation, Operations and Main-
tenance Manual supplied with each Vogt AOV valve. It is
recommended that Recommended Spare Parts for Actuators be
requested when ordering a Vogt AOV valve.
a CAUTION:
1. The system pressure shall be totally isolated and
vented from the valve and supply pressure removed
from the actuator when the valve is being repaired.
2. Consult Reference document #2 for safety
precautions when troubleshooting the actuator.
3. For small valves, replacement may be more
economical than repair. Vogt Valves can replace the
valve with one that will interface with the existing
actuator. The valve nameplate gives the drawing
number for the valve. Provide this to the authorized
Vogt distributor for replacement.
Bonnet Leaker/Seat Leaker for Vogt AOV Gate,
Globe or Angle Valve
1. See the applicable procedure for Gate, Globe or Angle valve
detailed in this manual for repair of bonnet and/or seat leaker.
2. Stem breakage is common with AOV valves during the early
stages of operation. To replace the stem, it is recommended that
the bonnet be removed and the old stem be replaced. Please
note the length of the old stem and new stem and the thread
engagement geometry of the valve stem and actuator coupling
nut. Make sure that the broken stem is totally removed from
the actuator coupling nut before replacing the new stem. If the
stems are the same length, make every effort to duplicate the
stem and actuator coupling nut engagement geometry noted
before old stem was removed. This will ensure that the final
stem/actuator coupling nut thread engagement adjustment will
be kept to a minimum.
3. For an AOV gate valve, the gate orientation shall be noted and
marked with the body to ensure that the same gate goes back
into the same valve in the same orientation as it was when it
was removed.
4. Replace the bonnet and torque bonnet bolts to the values noted
in Section 5 for the appropriate bolting size.
5. After resetting the open and close switches, place valve back in
operation.
Actuator Troubleshooting
The orientation of the valve may require that the stem/actuator cou-
pling nut have an additional adjustment before the valve is placed
back in service. If the valve is leaking across the closure seat, an
adjustment is necessary for a “fail-closed” valve and/or an increase
in supply pressure if the valve is a “fail-open” design.
For air actuator accessories, separate manuals may have to be
consulted to properly troubleshoot any issues.