Installation
Operation
Automax Valve Automation Systems
APEX 8000 High-Performance Positione
r
FCD AXENIM0130-00
Maintenance
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 instructions 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 equipment
.
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 required 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 as
the stem position changes. The spring-loading force is applied through 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.
