Valve Install Instructions

VG7000 Series Bronze Control Valves Product Bulletin 19
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 moves the valve plugs to a position where
the diaphragm pressure and the spring force balance
against the fluid forces. These fluid forces 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-3000-8012, MP82, and MP84 are
available with a V-9502 Pneumatic Positioner. The
V-9502 Pneumatic Positioner compensates for the
spring range shift, and the valve operates within the
published range. Refer to the Operation section of the
V-9502 Pneumatic Valve Actuator Positioners 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 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 for specifications and available
options.
VA7810 Series Electric Actuators
The VA7810 Series of non-spring return actuators
operates on 24 VAC and are available for use with
on/off (floating) or proportional controllers. Models are
available with two auxiliary switches and all
proportional models include a 0 (2) to 10 VDC
feedback signal. Proportional models are
self-calibrating and can also be used as an on/off and
floating actuator with a change of switch settings.
The direct mount series of actuators features a manual
override as standard, an IP54 enclosure, a status
Light-Emitting Diode (LED) and a brushless motor for
long life. Refer to the VA7800 Series Electric Valve
Actuators Product Bulletin (LIT-12011474) for
specifications and available options.
VA7820/VA7830 Series Electric Actuators
The VA7820 spring return stem up or VA7830 spring
return stem down series of actuators operates on
24 VAC. Actuators are shipped already set for
proportional control but with a simple change of switch
settings, can be changed to on/off or floating control.
The actuators are self-calibrating and come standard
with a 0 (2) to 10 VDC feedback signal, manual
override, an IP54 enclosure, a status LED, and a
brushless motor for long life.
Models with two auxiliary switches are available. Refer
to the VA7800 Series Electric Valve Actuators Product
Bulletin (LIT-12011474) for specifications and available
options.
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