Product Overview

VG7000 Series Bronze Control Valves Product Bulletin20
Operation
V-3000, V-3801-8001, and MP8000 Series
Pneumatic Actuators
Air pressure from a pneumatic controller is applied to
the diaphragm of the actuator, which moves the piston
against the forces of the internal spring and the fluids.
The piston will move the valve plugs to a position
where the diaphragm pressure and the spring force
balance against the fluid forces. These fluid forces will
cause the operating ranges to shift from the nominal
spring range. Reducing the air pressure to the
diaphragm of the actuator allows the spring to return
the valve plug to its normal position.
For applications requiring stable, accurate control and
sequencing, the V-3000-8011, MP82, and MP84 are
available with a V-9502 Pneumatic Positioner. The
V-9502 Pneumatic Positioner will compensate for the
spring range shift, and the valve will operate within the
published range. Refer to the Operation section of the
V-9502 Pneumatic Valve Actuator Positioner Product
Bulletin (LIT-977265) for more details.
To ensure installed performance quality and optimal
maximum closeoff pressure when using the positioner,
the following spring ranges are recommended:
Positioners are factory calibrated to match the nominal
spring range of the actuator and valve assembly.
VA-715x and VA-720x Series Electric Valve
Actuators
The VA-715x and VA-720x Series Actuators operate
on 24 VAC, and are available for on-off/floating control
action or proportional control. A reversible synchronous
motor and a magnetic clutch are used to accurately
position the valve. The actuator maintains position
even if power to the actuator is removed. The magnetic
clutch maintains a constant load at the end of travel,
which ensures tight valve shutoff and compensates for
seat wear. Refer to the appropriate electric valve
actuator literature in the for specifications and available
options.
VA-8x2x Series Electric Valve Actuators
The VA-8x2x Series Actuators operate on 24 VAC, and
are available for on/off, floating, or proportional control.
The signal drives the actuator motor, causing the valve
stem to move in the desired direction. Once the valve
stem reaches the end of travel, a shutoff force builds
up. When the force reaches its maximum, a lever within
the actuator trips a force sensor, which stops the
motor.
Field calibration of the force sensor is not required. The
actuator maintains the shutoff force even if power to
the controller is lost. Valve stem positioning can be
accomplished manually by turning the adjustment knob
on the lower right portion of the actuator. Rotating the
adjustment knob counterclockwise moves the valve
stem up. Refer to the appropriate electric valve
actuator literature in the for specifications and available
options.
M9116/M9220 Series Electric Actuators
The M9116/M9220 Series Actuators operate on
24 VAC or VDC power, and are available for use with
floating or proportional controllers. When coupled with
the M9000-500 Valve Mounting, the rotary motion of
this actuator is converted into linear motion that will
operate 1/2 through 2 in. VG7000 Series Valves.
A compression spring on the output shaft of the
mounting automatically compensates for seat wear.
On three-way valves, the preset spring load is applied
at both ends of travel. On loss of power, the spring
return M9220 Actuator returns to its normal position.
Refer to the appropriate electric actuator literature or
the M9000-500 Valve Linkage Kit for M9116 and
M9220 Series Electric Actuators Product Bulletin
(LIT-977352) in the for specifications and available
options.
VA-4233 Series Electric Actuators
The VA-4233 Series Electric Actuators operate on
24 VAC or VDC power, and are available for use with
on/off, floating, or proportional controllers. These
actuators incorporate a stepper motor to accurately
position the valve. In the event of a power failure, a
spring in the actuator automatically returns the valve to
the full stem-up position. All models feature a hand
crank for manual positioning of the valve, independent
of a power supply.
Proportional models include an AUTO stroke
calibration feature that enables the actuator to redefine
the selected input signal and feedback proportionally
across the actual valve stroke. Initial application of a
power signal will drive the actuator and valve assembly
to the full stem-up position and then the full stem-down
position, and will store these positions in nonvolatile
memory (retains data when power is lost or removed).
The actuator will then drive to the position determined
by the applied control signal.
Normally Open Valve: 3 to 6 psig
(3 to 7 psig for MP82/MP84)
Normally Closed Valve: 9 to 13 psig
Three-Way Mixing Valve: 4 to 8 psig