Flowserve Valtek FlowTop General Service Control Valve - Manual (Page 3)

Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611 60-3
Mounting actuator on valve
1. Determine the stroke length of the valve,
0.79-inches (20 mm) or 1.57" (40 mm). Check the
stroke plate (213) to verify if necessary.
2. Push the plug stem down into the seat by hand to
fully close the valve.
3. Replace the complete actuator. Clean the threads
on the bonnet, using a light oil or fluid. Replace the
complete actuator onto the bonnet and install yoke
nut loosely.
4. Connect an adjustable air supply to the actuator.
5. On direct-acting actuators (air-to-close / fail-open):
Apply sufficient air pressure to the actuator to
extend the actuator stem (211) to 100 percent of
stroke (0.79- or 1.12-inches). Using a scale,
measure and verify the stroke of the actuator stem.
Stop stem travel once full stroke has been reached.
With the stem in this positioner, adjust the two stem
clamp halves and connect them using the stem
clamp bolting.
6. On reverse-acting actuators (air-to-open / fail-
closed): Retract the actuator stem (211) until it stops
against the upper diaphragm case (203). From this
position, using an adjustable air supply and a scale,
measure and verify the valve stroke. Once the stem
has traveled full stroke, stop the travel and hold the
stem in this position. Adjust the two stem clamp
halves and install the stem clamp bolting.
7. While attaching the stem clamp (249), make sure
there is full engagement of the threads on the stems.
Make sure to install the stroke indicator pointer (248)
and fully tighten the stem clamp cap bolts and nuts
(345, 240).
8. With the yoke nut loose, stroke the valve two or
three times to line up the yoke. Next, position the
valve at mid stroke (50 percent open).
9. Completely tighten the yoke nut securing the
actuator firmly to the valve.
10. Slight adjustments can be made (with the plug off
the seat) by re-adjusting the stem clamp positions.
11. Readjust the stroke plate (213) as necessary.
10. Spray a soap solution around the diaphragm joint
between the upper and lower diaphragm cases
(203, 202). Check the actuator case bolts (335) to
be certain they are tight.
11. Clean any dirt and other foreign material from the
plug stem.
12. If an air filter is supplied, check and replace the
cartridge if necessary.
13. Check the tightness of the bonnet nuts (114). See
Table II.
14. Check the tightness of the yoke leg nuts (349).
15. Check stem clamp bolting tightness (240, 345).
OVERHAULING PROCEDURE
Valve overhaul requires disassembling the valve body.
WARNING: Depressurize the line to atmospheric
pressure and drain all fluids before working on
the valve.
Make a thorough inspection of the plug, seat rings and
stem to determine whether these parts should be
reused, reworked or replaced.
NOTE: For an easy inspection of the valve trim, the
bonnet may be removed from the valve body with
the actuator still mounted and attached to the valve
stem. To minimize the possibility of leakage, always
replace the bonnet gasket and packing whenever
the valve is disassembled.
Actuator removal
1. Disconnect actuator and valve stem by removing
stem clamp bolts and clamp (240, 345).
WARNING: On fail-closed actuators, the
preadjusted spring force is effective. Therefore,
apply enough air pressure to the actuator to
stroke the stem to the mid-position (50 percent
stroke) before disconnecting actuator and
valve stem.
2. Reduce the loading pressure in the actuator to
atmosphere.
3. Disconnect the pneumatic connection to the
actuator.
4. Remove the yoke nut (XXX) from the bonnet (40).
5. If the actuator does not lift freely off the bonnet (40),
then apply pressure to the actuator and drive the plug
into the seat. This should drive lift the yoke off the
bonnet.
6. Lift the actuator off the valve.
Table II: Bonnet Bolting Torque Values
IM049 FlowTop IOM.p65 2/10/03, 12:34 PM 3