Flowserve Valtek Mark Two User Instructions page 11

7.5. Install new bonnet and seat gaskets with the bevelled edge
up for Teflon gaskets.
7.6 Insert the seat ring into the body with the step side down.
When the seat ring is properly in place it will turn easily in
the body. Place the seat retainer into the body with the thin
end of the cathedral window down. Most retainers have an
arrow pointing up to verify correct installation. For pressure
balanced valves, install the pressure balanced sleeve gasket.
Ensure that severe service retainers are correctly indexed by
turning the retainer in the body. Correctly aligned retainers
should turn easily.
a
CAUTION: Installing seat retainers upside down can damage
the control valve parts.
a
CAUTION: Seat rings, retainers and pressure balanced
sleeves must be installed squarely into the body to function
correctly. To check to make sure the parts are installed
correctly, rotate these parts a little by hand. The parts should
rotate freely without binding.
NOTE: When the seat retainer has only two ports, one of the
two ports should be aligned with the upper port of the body.
7.7 Place air under the actuator piston on air-to-open valves to
retract the plug.
7.8 Lower the plug and bonnet squarely into the body. Be careful
not to scratch or gall the plug as it enters the body.
7.9 To properly align the seat ring and plug, first bring the
bonnet bolting to finger-tightness.
7.9.1 With pneumatic actuators, apply air pressure above the
piston to seat the plug in the seat ring. Proceed to step 7.10.
7.9.2 With electric or hydraulic actuators, move the actuator
stem down until it is completely extended. Next, retract the
actuator stem 1/8 inch (3.2 mm). Install the stem clamp onto
the plug stem and actuator stem and tighten the associated
bolting. Move the actuator stem completely down. Adjust
actuator limit switches according to the actuator's operating
manual. The actuator limit switches will need to be readjust-
ed once the body bolting has been tightened.
NOTE: Step 7.10 applies only to valves with pneumatic
actuators. If an electric or hydraulic actuator is used, return
the plug to the mid-stroke position and proceed to tighten.
a
CAUTION: Failure to return the plug to a mid-stroke position
(electric or hydraulic operators only) will cause damage to
the actuator and / or the valve during the bonnet tightening
sequence. This is due to the inability of most electric / hy-
Valtek Mark One and Mark Two Control Valves FCD VLENIM0001-02-A4 - 05/16
7.10
7.11
7.12
a
7.13
7.14
7.15
draulic actuators to accommodate the 1/16 inch / 1.60 mm
back-drive during the tightening sequence.
For air-to-close valves, skip this step and go to step 7.11.
For air-to-open valves, check for proper plug seating as
follows: When proper seating occurs, the bonnet flange will
be forced up against the finger-tight body bolting with such
force that it will be impossible to move the flange. If proper
seating does not occur, the bonnet flange can be wiggled
with light hand force for small valves and light wrench
force for larger valves. Should this occur, place air under
the actuator piston and retract the actuator to approximate
mid-stroke position. Turn the plug out of the actuator
plug stem one additional thread and repeat above seating
procedure. When the bonnet flange becomes tight against
the finger-tight body bolting, the plug is properly seated.
If necessary, repeat above procedure until proper seating
occurs.
Stroke the valve open and closed several times to center
the seat ring. Retract the plug (open position). Begin tight-
ening the bonnet flange bolting in a manner that will keep
the bonnet flange square / parallel with the body. Tight-
en the first bolt 1/6 turn, or one nut flat, then tighten the
bolt directly opposite 1/6 turn and so on around the flange.
Firmly tighten all bolts evenly and completely to compress
the bonnet gasket and to seat the bonnet. Torque the bon-
net bolts to the suggested torque values in Table II. The
bonnet will seat metal to metal with the body when the
bonnet bolts are correctly torqued into place
Apply air over the piston to seat the plug. For all throttling
valves with analog positioners, when the valve is in its fail
safe position, adjust the stem clamp slightly so that the full
open or full closed scribe line on the positioner cam points
to the center of the cam roller bearing. Adjustment can be
made by sliding the stem clamp on the actuator stem.
CAUTION: Make sure the slots of the stem clamp are
perpendicular to the bolting. See Figure 5.
NOTE: For on / off valves and valves with digital position-
ers, the bottom of the stem clamp should simply be lined
up with the bottom of actuator stem ± 1/16 inch (1.6 mm).
Tighten the stem clamp bolting. Proper tightness is
important since this adjustment secures the actuator stem
to the plug stem. Adjust the stroke plate so the stem clamp
points to the "closed" position.
If the valve has been taken out of the line, make sure the
flow arrow indicates proper flow direction upon reinstalla-
tion.
Adjust and test all accessories.
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