Flowserve Valtek VL-ES Actuators - Manual (Page 10)

Valtek VL-ES Actuators FCD VLENIM0114-00 – 09/06
10
NOTE: Rotating the plug while it is in contact with the seat will cause damage to both the plug and seat
ring. Take care not to allow the plug to rotate while threading the actuator onto the plug stem.
5.24 Apply air to the actuator to lift the plug off the seat. Tighten the stem clamp and yoke bolts. Use
Table IV to find torque values for the yoke bolts. Stroke fully open to fully closed several times to
verify operation.
Table IV: Yoke Bolt Torque Values
Actuator Size Spud Size
Connection
Type
Bolt Size
Carbon Bolting
(ft-lb)
Stainless
Bolting (ft-lb)
100-200 3.38 Bolted Bonnet 0.62-11 44 33
100-200 4.00 Bolted/Half Ring 0.62-11 44 33
100-200 4.75 Bolted Bonnet 0.62-11 44 33
300-600 3.38 Bolted Bonnet 0.75-10 80 60
300-600 4.00 Bolted/Half Ring 0.75-10 80 60
300-600 4.75 Bolted Bonnet 0.75-10 80 60
5.25 For ATC, fail open, valves, remove the air from the actuator and allow the valve plug to backseat
on the bonnet. This should put the plug at the top of the stroke. Using feeler gauges check to
make sure that the upper spring button is not contacting the top of the spring-can. If the upper
spring button is in contact with the top of the spring-can, the spring load is not being applied into
the plug and will need to be adjusted.
5.26 Install the cover plate, cover plate O-ring, bolts and lock washers, using anti-seize compound.
6 Maintenance
At least once every six months, check for proper operation by following the preventative maintenance
steps outlined below. These steps should not be performed while the actuator is in service. If an internal
problem is suspected with the actuator, refer to the Disassembly and Assembly sections (Sections 4 and
5 respectively).
WARNING: To avoid serious injury, the following steps should only be performed with the air supply
or positioner input disconnected.
6.1 When disconnecting air supply, observe actuator for correct fail-safe action.
6.2 Examine the actuator for damage caused by corrosive fumes and process drippings.
6.3 Clean the actuator and repaint any areas of severe oxidation.
6.4 If possible, stroke the actuator and check for smooth, full-stroke operation.
WARNING: To avoid serious injury, keep hands, hair and clothing away from all moving parts while
operating the actuator.
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