Flowserve XL Series High-Performance Positioner - Manual

Valtek No. 10077320 45-1
GENERAL INFORMATION
This bulletin is designed to assist in installing, calibrat-
ing, troubleshooting and performing maintenance as
required for the Valtek
® XL Series high-performance
positioner.
Product users and maintenance personnel should thor-
oughly read and strictly follow the instructions con-
tained in this bulletin prior to operating the positioner.
Any questions concerning this product should be di-
rected to a Flowserve representative.
To avoid possible injury to personnel or dam-
age to valve parts, WARNING and CAUTION
notes must be strictly followed. Modifying this
product, substituting non-factory parts or us-
ing maintenance procedures other than out-
lined could drastically affect performance and
be hazardous to personnel and equipment.
The XL high-performance positioner is a two-stage
device and is designed for use in control loops where
fast response is required. The XL 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 XL 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 XL high-performance positioner must
use the I/P NT 3000 Transducer. The I/P 2000 Trans-
ducer is not acceptable for use with the XL Series
Positioner.
The XL 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 pneu-
matic 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 XL Series positioner features an adjustable gain of
400-1100:1. The medium gain setting is standard on
size 25 actuators, while the high gain setting is standard
on size 50 and larger actuators (refer to ‘Gain Adjust-
ment Procedure’ section for further details.)
All positioners come with one of two types of cams:
a linear characteristic cam for use on linear actuators or
a combination linear / modified equal percentage
characteristic cam for rotary actuators. Refer to the
‘Rotary Actuator Cam Characteristic’ chart on page 4 for
specific installed characteristics.
POSITIONER OPERATION
The positioner schematic (Figure 1) shows an XL Series
positioner connected for double-acting service on a
linear actuator. Tension on the feedback spring pro-
vides feedback to the positioner, which varies as the
stem position changes. The spring-loading force is
applied through the feedback linkage and cam to the
positioner’s input capsule.
Instrument signal pressure is applied between the dia-
phragms 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.
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 oppos-
ing forces are not in balance, the input capsule will move
up or down and, by means of the pilot-valves, will
Valtek XL Series
High-Performance
Positioner