Reversing The Air-Action - Flowserve Valtek VL-C User Instructions

7. Install the tie rods into the yoke using Loctite No. 242 NSF61 or
equivalent.
8. Install the cylinder, making sure the cylinder is completely seated
on the yoke. Care should be taken not to scar or cut the piston and
yoke O-rings.
9. Replace the cylinder end cap and secure to the tie rods using new
self-locking nuts. Refer to Table II for the appropriate torque values.
0 WARNING: To avoid personal injury, the cylinder end cap
must be solidly in place. The cylinder end cap may fly off
when pressurized.
10. Reinstall the adjusting screw fitted with a new adjusting screw
gasket.
NOTE: Be certain the hole in the spring button is directly centered
under the adjusting screw hole in the cylinder on air-to-retract
configurations.
11. Tighten the adjusting screw enough to provide an air seal with the
gasket. Do not overtighten.
Table II: Tie Rod Torque Values
Actuator Size
50
100
150
200
12. Reinstall the stem bellows and stem clamp.
NOTE: To ensure maximum clamping strength when installing the
stem clamp, make sure the stem clamp bolting is perpendicular to
one of the slots machined into the actuator stem.
13. Apply air over the piston. Tighten the stem clamp bolting with the
stem clamp adjusted to point at the closed position of the stroke
indicator plate.
NOTE: If the actuator is installed on a Flowserve valve, refer to the
appropriate installation, operation, maintenance instructions for
correct plug stem thread engagement.
14. Reconnect tubing, supply and signal lines.
8
Torque for Min. Assy Torque for Min. Assy
Force (ft-lb) Force (Nm)
27
73
110
142
Valtek VL-C Spring Cylinder Linear Actuators FCD VLAIM054-01 – 06/13

Reversing the Air-action

To change the air action from air-to-retract to air-to extend, or vice
versa, refer to Figures 1, 2 or 4:
NOTE: Dual spring actuators are not reversible.
1. Disassemble the actuator according to the Disassembling the
Actuator section.
2. For air-to-retract action, reassemble the actuator with stem spacer
and spring button over the piston.
3. For air-to-extend action, reassemble with spring and stem spacer
below the piston and with the spring button stored above the
piston.
4. Reassemble the actuator according to the Reassembling the
Actuator section.
5. The positioner must also be reversed. See the appropriate
positioner maintenance instructions.
37
99
149
193