Installation
Automax Valve Automation Systems
APEX 8000 High-Performance Positioner
FCD AXENIM0130-00
Principles of Operation:
This bulletin is designed to assist in installing, calibrating, troubleshooting and performing maintenance as required for
the APEX 8000 Series high-performance positioner.
Product users and maintenance personnel should thoroughly read and strictly follow the instruction s contained in this
bulletin prior to operating the positioner. Any questions concerning this product should be directed to a Flowserve
representative
To avoid possible injury to personnel or damage to valve parts, WARNING and CAUTION notes must be
strictly followed. Modifying this product, substituting non-factory parts or using maintenance procedures
other than outlined could drastically affect performance and be hazardous to personnel and equipm ent.
The APEX 8000 high-performance positioner is a two-stage device and is designed for use in control loops where fast
response is required. The APEX 8000 positioner is designed to be modular and use the P/P module for 3-15 psi input
signal or the NT 3000 Series Transducer Module for 4-20 mA input signal.
The APEX 8000 high-performance positioner is designed as a four-way device, but can easily be converted to a
three-way device by plugging one of the output ports.
NOTE: The APEX 8000 high-performance positioner must use the I/P NT 3000 Transducer. The I/P 2000 Transducer
is not acceptable for use with the APEX 8000 Series Positioner.
The APEX 8000 positioner can handle supply pressures up to 150 psi; thus, a supply regulator is usually not
required. However, a five micron air filter is required for pneumatic positioners and a coalescing filter is re quired for
I/P positioners.
NOTE: The air supply should conform to ISA Standard S7.3 (a dew point at least 18° F / -8° C below ambient
temperature, particle size below 5 microns, oil content not to exceed one part per million).
The APEX 8000 Series positioner features an adjustable gain of 400-1100:1. The medium gain setting is standard for
smaller actuators, while the high gain setting is used on larger actuators (refer to ‘Gain Adjustment Procedure’ section
for further details.)
OPERATION:
The positioner schematic (Figure 1) shows an APEX 8000 Series positioner connected for double-acting service on a
rotary rack-and-pinion actuator. Tension on the feedback spring provides feedback to the positioner, which varies a s
the stem position changes. The spring-loading force is applied throu gh the feed-back linkage and cam to the
positioner’s input capsule.
Instrument signal pressure is applied between the diaphragms in the input capsule. Therefore, the input capsule
serves as a force-balance member, matching the valve stem position (as measured by tension on the feedback
spring) to the instrument signal.
Operation
Maintenance
When the opposing forces balance exactly, the system will be in equilibrium and the stem will be in the exact position
called for by the instrument signal. If the opposing forces are not in balance, the input capsule will move up or down
and, by means of the pilot-valves, will change the output pressures, moving the stem until the tension on the feedback
spring exactly opposes the instrument signal pressure
Figure 1: Apex 8000 Positioner Schematic for Air-to-Open
The sequence of operation is as follows: An increase in instrument signal pressure forces the input ca psule
downward. Displacement of the capsule in turn moves the flapper away from the detecting nozzle. This allows a larger
flow rate through the nozzle, decreasing the pressure exerted on the top of the pilot valve capsule.
Supply air biases the pilot-valve in an upward direction. As the capsule moves up, it will close the exhaust seat of the
upper pilot poppet and open the supply seat, which applies increased air pressure to the bottom cylinder port. At the
same time, the pilot-valve capsule will open the exhaust seat for the lower pilot poppet; thus, decreasing pressure to
the top cylinder port.
This difference in pressure will drive the piston outward, rotate the pinion and stretch the feedback spring until the
spring tension exactly opposes the force resulting from the instrument signal pressure. At this point, the flapper will be
moved toward the detecting nozzle to restore the pressure above the pilot-valve capsule to its equilibrium value. As a
force-balanced condition is approached, the pilot-valve capsule will be forced back to a neutral position where the
pilots are neither supplying air to, nor exhausting air from, their respective sides of the piston.
A decrease in instrument signal pressure reverses the described actions and cause a proportional inward movement
of actuator pistons and a reversal in pinion direction.
Installation of APEX 8000 Series Positioner on Actuators:
The APEX 8000 can be installed on most sizes of rotary and linear actuators. Actuators can be either double acting or
spring return. Cams can be used for direct acting or reverse acting directions. These instructions apply to rotary actuators
only. For linear actuator mounting instructions, consult the factory.
NOTE: For retrofitting to an actuator equipped with an Apex positioner, the same bracket and bolting may be used.
NOTE: NAMUR mounting is available with the APEX 8000 position-er. When retrofitting the APEX 8000 positioner to an
actuator equipped with another positioner, remove the existing posi-tioner, tubing and associated bolting. See tubing
instructions in Connecting APEX 8000 Positioner Ports section.
Mounting Instructions for APEX 8000 with NAMUR Shaft Connection
1. Mount the bracket to the actuator. Finger tighten the bracket bolting.
2. If required, install a coupler on the actuator shaft. Make sure the shaft and coupler are centered. See Figure 2.
3. Verify the orientation of the actuator and coupler flats match the positioner flats on the end of the shaft. Loosen the
cam if necessary. (See “Cam Installations” instructions.)
4. Install the positioner onto the bracket. Make sure positioner shaft and coupler are engaged and cente red. Finger
tighten positioner bolts.
5. Proceed to “Connecting APEX 8000 Positioner Ports.”
Connecting APEX 8000 Positioner Ports:
1. For double acting actuators, connect positioner ports 1 and 2 to the actuator. Port 1 is always connected to the
actuator port used to drive the actuator away from its start or fail position (the factory cam setting is full clockwise at
minimum input signal).
NOTE: For single acting, spring return actuators, plug output port
2. Connect supply air to the port marked “SUPPLY.”
3. Connect air (for pressure inputs) or instrument tubing or wiring (for 4-20 mA inputs). For current inputs, the
terminal is marked (+) and (-) inside the I/P module. The I/P is factory calibrated and should not require adjustment. If adjustments are necessary, see “Calibrating I/P Module Zero and Span Settings” section
air pressure higher than 30 psi may damage the module gauge and instrument signal cap sule; a 3-15 psi instrument
signal is recommended on the pneumatic module.
4. Stroke actuator/valve two or three times to align positioner, coupler and actuator. With 50% input (actuator/valve
at 45 degrees), tighten all mounting bolts. Stroke actuator/valve again to verify there is no misalignment
throughout the stroke.
5. Calibrate valve and adjust cam if necessary. (See “Cam Installation” and “Positioner Calibration” instruction s.)
. Caution: Signal
Cam Removal :
Disconnect cam return spring. With a wrench carefully placed on the output shaft (if necessary), loosen and remove the
jam nut. Remove pressure from the span arm by pushing it away from the cam. Remove the cam.
Cam Installation:
1. Make sure shaft is properly aligned with coupler or actuator.
2. Push span arm away from shaft to avoid pressure on the cam.
3. Place cam over the shaft with the appropriate characteristic facing up and closest to the span arm roller. “D”
represents direct-acting and “R” represents reverse acting.
4. Make sure the round mark on the left hand side of the characteristic curve is lined up with the span arm roller bearing.
See Figure 3
5. Tighten jam nut making sure cam does not rotate. Use a flat screwdriver to prevent cam rotation and shaft flats to prevent shaft rotation (if necessary)
6. Connect supply pressure to port marked ‘Supply.’stroke actuator/valve two or three times to align position with
actuator. With a 50 percent input signal, tighten all mounting bolts. Stroke actuator to verify proper alignment.
Position Calibration:
Introduction
APEX 8000 positioners are calibrated at the factory; however, due to shipping and handling, it may be necessary to check
the calibration before operating the valve. The APEX 8000 positioner can be calibrated to a range of 3-15; two-way split
range, 3-9, or 9-15; and three-way split ranging, 3-7, 7-11, 11-15 psi using the standard feedback spring.
WARNING: When stroking the actuator during calibration, keep hands, hair and clothing away from moving parts.
Failure to do so may cause serious personal injury.
Note: Positioners and I/Ps are calibrated at the factory. Use mechanical adjustments in positioner for calibration.
Zero and span on the I/P should not be used to calibrate the valve.
For calibration, refer to Figure 4 and proceed as follows:
1. For 3-15 or 3-9 psi range, loosen by hand the zero adjustment locking knob and adjust the zero adjustment knob until
the valve begins to stroke with more than 3 psi signal (for 9-15 psi range adjust to 9 psi).
2. Loosen the span adjustment locking screw no more than 1/8 turn.
3. With a phillips screwdriver adjust the span adjustment so valve is at full stroke with more than 15 psi for 3-15 or 9-15
psi range (adjust to 9 psi for 3-9 psi range).
4. Return to 3 psi (or 9 psi for 9-15 psi range) and check the zero. Repeat steps 1-4 if necessary
5. Tighten the zero adjustment lock knob and span adjustment locking screw.
6. Use the same procedure for three-way split range.
7. Connect Cam return spring. See Figure 4.
Positioner Balance Adjustment
CAUTION: Balance pressure is 75 percent of the supply pressure and is the average pressure of output ports 1
and 2. Balance is preset at factory. However, if this adjustment becomes necessary, carefully make this
adjustment slowly, allowing the positioner to stabilize. Check after a short while to make sure balance pressure
is correct.
Balance adjustment is set at the factory and should not need adjustment. Balance adjustment (output pressure level)
permits the equilibrium pressure in both sides of the actuator piston to be raised or lowered. The average actuator
pressure level of output 1 or 2 is approximately 75 percent of supply pressure. For single-acting actuators, the balance
pressure should be left at the factory setting. If it is necessary to adjust the output pressure level, follow the procedure
outlined:
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