COPES-VULCAN INSTRUCTION MANUAL
MODEL 700 DIRECT-ACTING ACTUATOR
Rev.5 (08/10) Page 8 of
20 Form 01:P224:37
2.3 STEM CONNECTOR AND TRAVEL ADJUSTMENT
(CONT’D.)
2.3.3 Reverse-Seated Valve
A reverse-seated valve is closed by applying upward force on the valve stem.
For the case of a reverse-seated valve where a valve backseat is not present, the actuator will be
set up so that downward, or opening, motion of the valve stem is limited by the internal stop in the
actuator and upward, or closing, motion of the stem will be limited by the valve mainseat.
A. Place the stem lock plate over the valve stem, then thread the stem clamp (Item 27) fully onto
the valve stem. Thread the upper stem weldment (Item 22) onto the actuator stem (Item 16)
so that the bottom surface of the upper stem weldment is approximately 0.06" (1.5 mm)
above the bottom of the actuator stem.
B. Position the valve stem to the full open position. Tighten the packing nuts as necessary to
hold the valve stem in this position. The full open position can be established by first pulling
the valve stem up to the seated position, then lowering the stem by an amount equal to the
travel given on the valve specification sheet.
C. Apply sufficient air pressure so that the actuator stem is fully extended, but do not exceed 80
psig (5.5 bar).
WARNING! Never exceed the actuator allowable air pressure rating. Property
damage, injury or death may occur.
Rotate the stem clamp up on the valve stem so that contact is made with the bottom of the
actuator stem. Pull up the stem lock plate and install the four 7/16"-14 socket head cap
screws (Item 23) with lockwashers (Item 24). Torque the cap screws to 24 ft-lb (33 Nm).
Maintain parallelism between the stem lock plate and the upper stem flange.
D. If necessary, adjust the position of the indicator plate (Item 8 on the assembly drawing).
To Next Page
Loading...
Need help?
General