Changing Valve Flow Direction - Fisher CV500 Instruction Manual

CV500 Valve
June 2017
Any of the Fisher pneumatic, electric, electrohydraulic, or manual actuators‐‐or any other actuator‐‐must be adjusted
for use with a CV500 valve so that the ball is rotated to the fully closed position. A gap of approximately 0.0254 mm
(0.001 inch) for temperatures to 260_C (500_F) or 0.1524 mm (0.006 inch) for higher temperatures measured
between the seat ring (key 5) and retainer (key 4) indicates the fully closed position.
Note that this gap is also measured when assembling the seat ring, retainer, and face seals to ensure correct assembly.
Measure the gap according to this procedure to ensure proper actuator adjustment. Merely completing the assembly
measurement is not sufficient.
Travel adjustments vary with the type of actuator (some use turnbuckle assemblies; some use externally adjusted
travel stops; others use internal limit switches). Refer to the actuator instruction manual for adjustment instructions.
Note
When mounting the actuator, be sure the ball (key 2) is closed. Do not use a hammer or other tool to drive the actuator lever onto
the valve shaft. Clean the valve shaft and actuator lever splines to be sure the actuator lever will slide on easily.
If the lever does not slide on easily, carefully wedge the ball solidly against the actuator‐side thrust washer using a screw driver or
similar tool in the same location as the pry bar in the installation. Keep the wedge in place while installing the lever, but again, do
not drive on the lever.
Remove the wedge after you have clamped the actuator lever on the valve shaft and connected the lever to the actuator piston
rod or diaphragm rod.
1. Mount the actuator following the instructions in the actuator instruction manual. Refer to figure 2 to select
actuator mounting style and position and to orient the actuator lever with the valve drive shaft (key 3).
2. For actuators with clamped levers, pull the drive shaft (key 3) by hand toward the packing (key 13) so that the ball
(key 2) and thrust washer (key 12) are tight against the bearing closest to the packing (key 6 for NPS 3 through 8
and key 42 for NPS 10 and 12). Clamp the lever to the valve drive shaft.
CAUTION
Do not apply full actuator signal (pressure or power) to the actuator in the next step. A full signal may wedge the ball into
the seat ring. Use a regulated signal source and gradually increase the signal to slowly stroke the actuator.
3. Adjust the actuator travel and stroke the actuator so that the ball is close to but not contacting the seat ring at full
actuator travel. If available on electric actuators, use the manual handwheel to position the plug.
4. Adjust the travel, using a full actuator signal, until the ball contacts the seat ring around its full circumference. This
contact self‐centers the seat ring on the V‐notch ball.
5. Continue to adjust the travel until a gap of approximately 0.0254 mm (0.001 inch) exists between the seat ring and
retainer, as shown in figure 10, at full actuator travel.
6. Refer to the actuator instruction manual to lock the actuator travel adjustment.

Changing Valve Flow Direction

The CV500 valve may be installed in either forward or reverse flow service. Standard flow direction is forward flow
enters the seat ring first, then flows past the V‐notch ball. If changing flow direction is necessary, release all pressure
from the valve and actuator. Remove the control valve assembly from the pipeline and rotate the assembly about the
valve drive shaft to put the retainer end of the valve where the other end was. Refer to the procedure for changing
actuator mounting style if the actuator must be repositioned, and refer to the installation section to install the control
valve assembly. Be sure to reposition the flow direction arrow on the valve.
22
Instruction Manual
D101640X012