Flowserve Valtek Mark 10 Survivor Control Valves - Manual (Page 9)

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Valtek Mark 10 Survivor Control Valves FCD VLENIM0036-05 – 07/09
flowserve.com
2.5.2.17. Replace the seat ring and seat ring gasket.
2.5.3. Valves with ceramic trims without actuator limit stops, or non-standard actuators
2.5.3.1. This procedure uses the adjustment of the plug stem and the actuator stem to limit
the travel of the plug. Any actuator limit stops should be set before proceeding.
2.5.3.2. Loosen the stem clamp to allow the plug to rotate in the actuator stem.
2.5.3.3. Using a wrench to keep the actuator stem from rotating, spin the plug into the
actuator stem until only one to one and a half threads are still exposed.
2.5.3.4. Check to make sure the seat ring and plug are clean of dirt, debris or any other
contamination.
NOTE: Flowserve can offer graphite ribbon which can be used to provide a thin pad between
the plug head and seat ring surfaces. It is recommended that similar padding be used to
lower the risk of ceramic fracture.
2.5.3.5. With all the seat gaskets removed, place the seat ring into the body and hold in
place using hand pressure.
2.5.3.6. Stroke the valve open.
2.5.3.7. Turn the plug out one quarter turn, or less when fine tuning the plug position.
2.5.3.8. Stroke the valve closed. Note if the plug contacts the seat ring. This can be felt as
the seat ring moves due to contact with the plug.
CAUTION: a Contacting the seat ring and plug with ceramic trimmed valves could cause
the seat ring or plug to fracture. Take great care in allowing these two surfaces to
contact. The seat ring should be allowed to slide out of the body smoothly, with only
light hand pressure to hold it in place. If the seat begins to bind, immediately stroke the
valve open. Remove the seat and check for dings or dirt. Stroke the valve slowly to avoid
slamming the plug into the seat ring.
2.5.3.9. Repeat steps 2.5.3.6 through 2.5.3.8 until the plug just contacts the seat. Stop as
soon as the two are in contact.
2.5.3.10. Stroke the valve open. Turn the plug back into the actuator stem one quarter turn.
This will ensure that the plug will not contact the seat during operation.
2.5.3.11. Remove the seat ring from the body. Set and tighten the stem clamp.
2.6. Remove all seat ring bolts and transport to installation location. For valves installed
horizontally, only remove the bolts holding the seat into the body.
2.7. Place seat ring and seat ring gasket into the downstream pipe.
2.7.1. When installing two piece seats, install the lower seat, with gaskets, then the upper
seat. After installing the upper seat, spin the upper seat a little to assure a proper fit.
2.8. Check all gaskets, including seat and line gaskets.
2.9. Verify that the plug is in the up position.
2.10. Lower the valve onto the seat ring, taking care not to cock. Install the bolting, finger tight.
NOTE: If the valve has separable end flanges, the half rings must be installed on the valve body
before bolting the valve into the line to insure a tight connection.
WARNING:
c
Failure to install half rings on the valve body can cause serious personal injury.