APM Pneumatic Modulevel Instruction Manual 48-630

APM Pneumatic
Control for Boiler Feed
System Applications
Installation and Operating Manual
Pneumatic
Control
Read this Manual Before Installing
This manual provides information on the APM
Pneumatic Control for Boiler Feed System Applications.
It is important that all instructions are read carefully and
followed in sequence. Detailed instructions are included
in the Installation section of this manual.
Conventions Used in this Manual
Certain conventions are used in this manual to convey
specific types of information. General technical material,
support data, and safety information are presented in
narrative form. The following styles are used for notes,
cautions, and warnings.
Notes
Notes contain information that augments or clarifies
an operating step. Notes do not normally contain
actions. They follow the procedural steps to which
they refer.
Cautions
Cautions alert the technician to special conditions that
could injure personnel, damage equipment, or reduce
a component’s mechanical integrity. Cautions are also
used to alert the technician to unsafe practices or the
need for special protective equipment or specific
materials. In this manual, a caution box indicates a
potentially hazardous situation which, if not avoided,
may result in minor or moderate injury.
Warnings
Warnings identify potentially dangerous situations or
serious hazards. In this manual, a warning indicates an
imminently hazardous situation which, if not avoided,
could result in serious injury or death.
Safety Messages
Follow all standard industry procedures for servicing electrical equipment when working with or around high
voltage. Always shut off the power supply before touching any components.
Low Voltage Directive
For use in Installation Category II. If equipment is used
in a manner not specified by the manufacturer, protection provided by the equipment may be impaired.
Notice of Trademark, Copyright, and Limitations
Copyright © 2004 Magnetrol International,
Incorporated. All rights reserved.
Magnetrol reserves the right to make changes to the
product described in this manual at any time without
notice. Magnetrol makes no warranty with respect to the
accuracy of the information in this manual.
Warranty
All Magnetrol/STI mechanical level and flow controls are
warranted free of defects in materials or workmanship for
five full years from the date of original factory shipment.
Repair parts are warranted free of defects in materials and
workmanship for one year from the date of shipment.
Materials, specifications, and contents are subject to
change without prior written notice.
If returned within the warranty period; and, upon factory
inspection of the control, the cause of the claim is
determined to be covered under the warranty; then,
Magnetrol/STI will repair or replace the control at no cost
to the purchaser (or owner) other than transportation.
Magnetrol/STI shall not be liable for misapplication,
labor claims, direct or consequential damage or expense
arising from the installation or use of equipment.
There are no other warranties expressed or implied,
except special written warranties covering some
Magnetrol/STI products.
Quality Assurance
The quality assurance system in place at Magnetrol/STI
guarantees the highest level of quality throughout
the company. Magnetrol/STI is committed to providing
full customer satisfaction both in quality products and
quality service.
Magnetrol’s quality assurance system
is registered to ISO 9001 affirming its
commitment to known international
quality standards providing the
strongest assurance of product/service
quality available.
APM Pneumatic Control
for Boiler Feed System Applications
Table of Contents
1.0 Introduction
1.1 Principle of Operation .............................................1
1.2 Operating Cycle.......................................................1
1.3 Description ..............................................................2
1.3.1 Controller Action..........................................2
1.3.1.1 Proportional Control .............................2
1.3.2 Controller Options .......................................2
1.3.2.1 Direct or Reverse Action ........................2
1.3.2.2 Electric Limit Switches...........................2
1.3.3 Mounting Arrangements ...............................2
1.3.3.1 Top Mounted APM-131........................2
1.3.3.2 External Cage APM-W251,
APM-W254, APM-W291 .....................2
2.0 Installation .....................................................................3
2.1 Unpacking ...............................................................3
2.1.1 APM-131 Model...........................................3
2.1.2 APM-W251, APM-W254, and
APM-W291 Models......................................3
2.1.3 Specifications ................................................3
2.1.4 Accessories.....................................................3
2.2 Mounting.................................................................4
2.2.1 Top Mounted Models – APM-131 ...............5
2.2.2 External Cage Models – APM-W251,
APM-W254, APM-W291 ............................5
2.3 Calibration...............................................................6
2.3.1 Proportional Controllers ...............................6
2.3.1.1 Calibration Chart instructions ...............8
2.3.2 Electric High/Low Limit Switches.................9
2.3.2.1 Electrical Ratings ...................................9
2.3.2.2 Wiring Information ...............................9
2.3.2.3 Adjustment Procedure..........................10
2.4 Field Modifications and Adjustments.....................10
2.4.1 Changing Controller Action........................10
2.4.2 Pneumatic-to-Current (P/I) Converter........10
3.0 Reference Information
3.1 Troubleshooting .....................................................11
3.1.1 Installation ..................................................11
3.1.2 Calibration..................................................11
3.1.3 Operation ...................................................12
3.2 Specifications .........................................................13
3.2.1 Models APM-131, APM-W251,
APM-W254, and APM-W291
Dimensional Specifications .........................13
3.3 Replacement Parts..................................................14
3.3.1 Model APM-131 Parts Identification ..........14
3.3.1.1 Model APM-131 Part Number ............14
3.3.2 Models APM-W251, APM-W254, and
APM-W291 Parts Identification .................15
3.3.3 Models APM-W251, APM-W254, and
APM-W291 Parts Numbers ........................16
3.3.3.1 Model APM-W251 Part Number ........16
3.3.3.2 Model APM-W254 Part Number ........16
3.3.3.3 Model APM-W291 Part Number ........16
3.3.4 Controller Parts...........................................17
3.3.5 Controller Parts Identification.....................18
3.3.6 Controller Part Number..............................19
3.4 Model Numbers.....................................................20
3.4.1 APM Pneumatic Control Models................20
1.0
Introduction
APM pneumatic controls are displacement actuated level
sensors that provide output signals in direct proportion to
changes in liquid level.
Simple modular design and proven magnetic coupling make
APM controls versatile, highly stable, vibration resistant
and adaptable to extremes of temperature and pressure.
1.1
Pilot Nozzle
Flapper
Cam
Attraction Ball
Magnet
Enclosing
Tube
Zero Adjustment
Indicator
The key elements of the APM pneumatic control are the magnetic coupling, which allows the controller to be
mechanically isolated from the sealed
sensing unit; the range spring, which
dampens the action of the displacer;
and the control head, which provides a
modulated pneumatic signal in direct
proportion to the input from the vertical motion of the displacer.
Proportional Band
Adjustment
Proportional
Band Spring
0
100
Range
Spring
Actuating
Lever
Set Point
Adjustment
Feedback
Bellows
Reset
Valve
Relay
Chamber
Displacer
Reset
Bellows
Check
Valve
Orifice
OUTPUT
Supply Pressure
SUPPLY
Filter
Regulator
Control
Valve
Output pressure
Principle of Operation
Pilot Pressure
Figure 1
1.2
Operating Cycle
The result of liquid level changes in
the vessel is a change in the buoyancy
force acting on the displacer and in
the load on the spring from which the
displacer is suspended. As the spring
extends or compresses with the change
in load, an attraction ball attached to
the spring via a stem assembly moves
within the enclosing tube.
A magnet encircling the enclosing
tube follows the attraction ball, transferring the motion to a rotating cam,
which in turn operates a flapper
against a nozzle which increases or decreases the pressure
within the pneumatic relay. The output pressure signal can
be used in a variety of ways; to operate a control valve,
signal alarms, indicators, process controls or other devices.
Reset Pressure
With optional proportional plus integral control, the output signal is conditioned through an adjustable restrictor
and bellows system, which eliminated offset from the
desired control point.
1
48-630 APM Pneumatic Control for Boiler Feed System Applications
1.3
Description
APM pneumatic instruments are available with a variety of
functions to handle different application requirements.
1.3.1 Controller Action
1.3.1.1 Proportional Control
Proportional control instruments are used to maintain the
level in a tank within a predetermined band. The output
from the APM head controls the opening and closing of a
valve to control the increase or decrease of the liquid flow
through the vessel.
1.3.2 Controller Options
1.3.2.1 Direct or Reverse Action
Direct acting controllers provide an output signal that
increases with level increases. Reverse acting controllers
provide an output signal that decreases with level increase.
1.3.2.2 Electric Limit Switches
Electric limit switches allow high and low level alarms
to be added to any of the pneumatic instruments
described above.
1.3.3 Mounting Arrangements
1.3.3.1 Top Mounted APM-131
When mounting inside the tank is possible, threaded top
models are the answer. An adjustable stainless steel displacer
suspension cable is provided as standard.
1.3.3.2 External Cage APM-W251, APM-W254,
APM-W291
Figure 2
Top Mounted
APM-131
External cage models can be easily isolated from the
process to simplify maintenance and inspection operations.
Sight glass and Try-cock tappings are provided.
Figure 3
External Cage
48-630 APM Pneumatic Control for Boiler Feed System Applications
2
2.0
Installation
2.1
Unpacking
After unpacking, inspect all the components to see that
no damage has occurred during shipment. Care should be
taken not to bend the displacer stem or enclosing tube
during unpacking or installation.
Next, open the controller case and remove magnet hold
down and nozzle lever retainers. Examine internal controller components for any obvious damage or loosened
parts. Check all air connections to make certain they are
free of any foreign matter.
2.1.1 APM-131 Model
Top mounting APM units are shipped from the factory
with the controller and displacer removed from the
head assembly and packed separately in the same carton
or crate.
2.1.2 APM-W251, APM-W254, and APM-W291 Models
All cage type APM units are shipped with the controller
removed from the chamber assembly and packed separately
in the same carton or crate.
A strap and wire assembly retains and protects the displacer within the chamber during shipment. The assembly
must be removed through the bottom connection before
start-up.
Caution: If reshipping to another location, displacer assembly must
again be secured using same strap and wire assembly.
2.1.3 Specifications
Description
Specification
Input psig
20 psig (3–15). 35 psig (6–30)
Housing
NEMA 1, 2, 3
Visual indicator
% Span
Air consumption
3 SCFH at 9 psig; 6 SCFH at 15 psig
Displacer
304 stainless steel
Trim
Stainless
2.1.4 Accessories
Description
3
Part Number
Filter regulator
06-9501-002
Output gauge
06-9501-003
48-630 APM Pneumatic Control for Boiler Feed System Applications
2.2
Mounting
Before assembling control to vessel, check with spirit level
to ensure that the mounting flange is horizontal. Proper
operation of the control depends on the APM controller
being vertical. The head assembly with sensing components is installed first, then the controller is placed carefully over the enclosing tube, rotated to desired position, and
then locked in place by securely tightening the locking
screw. Check to be certain the controller magnet can move
smoothly throughout its actuating stroke without binding
against the enclosing tube. If binding occurs, loosen the
slot-head screw, reposition magnet and tighten screw.
Caution: The threaded connection link protruding from the head
assembly is extremely fragile. DO NOT handle or place in
a position such that any amount of force is placed on the
stem. Proper operation of the control requires that the
stem is not damaged or bent.
Caution: Displacer spring and stem are fragile. Do not drop displacers into tank. Hand feed cable into position to avoid
bending stem.
Caution: Before rotating the controller, ensure that the set screws
on the housing base that secure the controller to the
e-tube have been loosened. Failure to loosen the set
screws prior to rotating the head may cause the enclosing
tube to loosen, resulting in the possible leakage of the
process liquid or vapor.
NOTE: Since controller is rotatable through 360°, it is important to
make certain controller locking screw is tight before installing
air or gas connections.
The supply and output air or gas connections provided on
the Modulevel are 1⁄4" NPT. These connections are clearly
indicated on the side of the controller. The filter-regulator
(if furnished) is to be set to deliver a 20 psig supply pressure
to a 3–15 psig output controller or a 35 psig supply pressure
to a 6–30 psig output controller. The main supply pressure
to the regulator should be between 25 and 250 psig (or 40
and 250 psig) and connected to the inlet side of the regulator. In order to protect the instrument from contaminants,
clean, dry air or gas must be used as a supply medium.
Caution: Do not overtighten fittings in supply and output connections. Overtightening may crack the housing outlets.
NOTE: Careful selection of nozzle location on tank or vessel should
be made to ensure minimum temperatures. Controller housing
temperatures greater than +200° F (+93° C) tend to reduce life
of diaphragms in the amplifying relay.
48-630 APM Pneumatic Control for Boiler Feed System Applications
4
2.2.1 Top Mounted Models – APM-131
Filter regulator
Controller
Supply
pressure
Output
pressure
Control
valve
Liquid
Level
Displacer
Check to be certain there are no tubes, or other
obstacles in the vessel to interfere with the
operation of the displacer. Still wells are recommended where a continuous agitation or motion
is prevalent.
NOTE: The still well must be vented at the top. Still well
installation should be checked to be certain tube (or
pipe) is plumb. An out-of-plumb still well may restrict
displacer movement.
Figure 4 shows a typical piping installation for a
top mounted unit to a tank or vessel.
2.2.2 External Cage Models – APM-W25,
APM-W254, WPM-291
Figure 4
Top Mounted Units
Filter Regulator
Controller
Supply
Pressure
Output
Pressure
Liquid
Level
Control
Valve
Figure 5
Chambered Units
5
The external cage type Modulevel should be
mounted on the side of the tank or vessel
via the side/side connections as shown in
Figure 5. Mid-range mark on control cage
should be aligned to correspond with desired
control level in tank or vessel.
NOTE: It is essential that the external cage assembly be
mounted plumb to ensure frictionless operation of its
internal displacer.
It is recommended that globe-type shut-off valves
be installed in each equalizing line to the cage
along with a blow-down valve (refer to Figure 5).
Equalizing lines should be sized at least as large as
connections provided on the cage.
Caution: Operation of all buoyancy type level devices
should be done in such a way as to minimize the
action of dynamic forces on the float or displacer
sensing element. Good practice for reducing the
likelihood of damange to the control is to equalize
pressure across the device very slowly.
48-630 APM Pneumatic Control for Boiler Feed System Applications
2.3
Calibration
2.3.1 Proportional Controllers
Each APM control is calibrated at the factory before shipment. Specified actions have been preset and all scales have
been calibrated. However, upon receipt of the instrument
the following calibration and adjustment procedure is
recommended for all controllers:
1
2
3
13
12
4
11
10
5
6
9
14
7
8
Figure 6
Proportional Controller with Reset
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Proportional band adjustment knob
Zero adjustment screw
Supply pressure gauge
Level adjustment knob
Magnet carriage
Level indicator
Output pressure gauge
Output connection
Supply connection
Action cam
Relay
Orifice cleanout plunger
Flapper nozzle assembly
Reset adjustment knob
Dire
ct
n
Actio
Figure 7
Pilot Nozzle Assembly
1. Check supply pressure:
After appropriate piping has been made to the filter
regulator and output connections, and checked for leaks,
the supply gauge, shown in Figure 6, should indicate
20 psig (35 psig for 6–30 psig controllers).
2. Check control action:
To check controller action, manually rotate the magnet
carriage to simulate an increase in level. Note the direction
of the output pressure change. (Rising level will increase
the output pressure on direct acting controllers.
Conversely, rising level will decrease the output pressure on
the reverse acting controllers.) The action cam and level
adjustment knob must both indicate the same action.
Should it be required to change the controller action, the
action cam can be manually rotated 180° to the desired
action. Make certain that the notch in the cam is set into
the tab of the pilot nozzle assembly. Cam actions are clearly marked on the cam face as indicated in Figure 7. A zero
adjustment will normally be required upon change.
NOTE: It is also important that the level adjustment knob scale action
be compatible with the cam action. The level adjustment knob
scale is printed DIRECT ACTION on one side and REVERSE
ACTION on the other. To change scales, remove level adjustment knob and turn over level scale. Replace knob with same
orientation on shaft as before removal.
3. Check level indicator zero setting.
A level indicator is furnished with each APM pneumatic
controller and is conveniently located inside the instrument case. The level indicator, shown in Figure 8 (page 7),
indicates the level as a percentage of the displacer length.
Figure 8 shows a liquid specific gravity of .8 with a
corresponding level reading of 45% and a process
temperature of approximately +250° F (+121° C). An
adjustment is provided on the level indicator to calibrate
the pointer and indicator scale when control is at
operating temperature.
NOTE: Consult factory for procedure to calibrate level indicator if
precise reading is required.
48-630 APM Pneumatic Control for Boiler Feed System Applications
6
NOTE: Consult factory for procedure to calibrate level indicator if
precise reading is required.
Calibration Scale
Adjustment Screw
100°F
400
700
T
E
M
P
LEVEL
% DISPLACER
LENGTH
Magnet
Carriage
Slide Bar
0
20
Pointer
40
60
80
100
.90
1.0
1.1
S
.80
P.
.70
G
.60 .50
4.
With the system at operating temperature, adjust level of
process liquid in the tank (or vessel) to allow the displacer
to "hang-free" above the liquid. The pointer on the level
indicator should read zero percent on the indicator scale.
Refer to Figure 8. To adjust, loosen calibration adjustment
screw at the top of the indicator scale and move scale until
the pointer is aligned to zero.
Select level and proportional band:
(The level adjustment is the control set point.) The level
adjustment knob, located just below the supply pressure
gauge, indicates the percent of the displacer submerged in
the liquid. The output pressure is at 50% when the displacer
is submerged to the level set point.
R.
Figure 8
Level Indicator
(The proportional band is the span setting.) The
proportional band adjustment knob, located adjacent
to the pilot nozzle assembly, determines how much the
level will vary along the displacer length. When the
proportional band is set to 5, the output range will
correspond to 50% of the total displacer length at
1.0 specific gravity.
The proper method for calibrating a proportional
controller follows:
Calibration example: 1.00 specific gravity liquid, 50%
proportional band desired, 50% level adjustment desired,
3–15 psig output, direct action.
4.1 Set the pointer on magnet carriage slide bar to 1.00
specific gravity.
4.2 Set both the level and proportional band knobs to
5 (or 50%) on each scale.
4.3 Move the magnet carriage by hand until the pointer reads
50% of displacer length, hold accurately at this position.
4.4 Adjust the zero screw until the output pressure gauge reads
9 psig.
4.5 Move the magnet carriage pointer to 75% displacer length.
Output pressure should read 15 psig.
NOTE: If required, small readjustments can be made at the level and
proportional band knobs.
5.
Set the level and proportional band for your application.
Use calibration chart and instructions given in Figure 7
(page 6) to select the level and proportional band dial settings based on the specific gravity of liquid to be gauged.
5.1 Set the magnet carriage slide bar to the correct liquid
specific gravity for your application.
7
48-630 APM Pneumatic Control for Boiler Feed System Applications
5.2 To check the zero adjustment, bring the liquid level up
until the level indicator reads the desired level set point.
Set the zero adjustment screw until output pressure gauge
reads 9 psig.
6.
To check the level and 3–15 settings:
Adjust the liquid level until the level indicator reads the
low value of the desired span range in terms of % of
displacer length. The output pressure should read 3 psig.
Adjust the liquid level to the maximum value of the
desired span range in terms of % of displacer length.
The output pressure should read 15 psig.
With the system at operating temperature, adjust level of
process liquid in the tank (or vessel) to allow the displacer
to “hang–free” above the liquid. The pointer on the level
indicator should read zero percent on the indicator scale.
Refer to Figure 8 (page 7). To adjust, loosen calibration
adjustment screw at the top of the indicator scale and
move scale until the pointer is aligned to zero.
2.3.1.1 Calibration Chart instructions
To set level:
1. Determine the desired level set point in terms of % of
displacer length.
2. Trace desired level from left to right to the specific gravity
line for the product.
.1
.2
.3
.4
.5
.7
.8
120
110
100
90
80
.9
1.0
1.2
70
60
50
40
30
20
10
1.4
1.6
1.8
SPECIFIC GRAVITY
% DISPLACER LENGTH
NOTE: Proportional band must be reduced by % deviation from 50%
mid-point x 2. For example: 25% of displacer length mid-point
requires a 50% span reduction.
.6
150
140
130
3. Trace down from where the two lines intersect to the
appropriate dial setting.
4. Adjust the level setting on the controller to this value.
1.
0
1
2
3
4
5
6
7
8
9
10
DIAL SETTING FOR LEVEL & PROPORTIONAL BAND
2.
3.
Figure 9
Dual Setting for Level & Proportional Band
4.
To set proportional band:
Determine the desired proportional band in terms of % of
displacer length.
Trace from left to right to the specific gravity line for product.
Trace down from where the two lines intersect to the
appropriate dial setting.
Adjust the proportional band setting on the controller to
this value.
NOTE: If required, small readjustments can be made at the level and
proportional band knobs. To increase proportional band, the
band knob is turned to a higher number. For best control, it is
normally desirable to set the proportional band at the narrowest setting which will not produce cycling. To raise the level,
the level adjustment knob is rotated in the desired direction
indicated on the dial face.
48-630 APM Pneumatic Control for Boiler Feed System Applications
8
2.3.2 Electric High/Low Limit Switches
The APM controller is available with optional built-in,
adjustable electric high/low level limit switching. This
economical, optional feature is well-suited to numerous
applications where a combination pneumatic control and
electric switch actuation is desired.
The APM controller is used to pneumatically position a
diaphragm-type feedwater control valve in response to
water level changes in the steam drum. The convenient
addition of electric limit switching provides economical
high and low level alarm indication. These switches are not
intended for primary control purposes.
NOTE: Not suitable for Class I, Div. 1 applications.
2.3.2.1 Electrical Ratings
Each reed switch, without the optionally available relay,
carries the following electrical ratings:
Maximum voltage .................120 VAC or 120 VDC
Maximum resistive load..................10 VAC or VDC
Maximum current .....................1⁄4 ampere switching,
1 ampere holding
NOTE: For lamp or capacitive applications, the reed switches are
rated six (6) watts maximum.
2.3.2.2 Wiring Information
Each reed switch assembly is wired at the factory and
furnished with number-coded, 24 inch long silicone
rubber insulated copper lead wires. Each reed switch is
SPDT in operation. Standard wiring follows:
High level reed switch
No. 5 lead is common
No. 6 lead energizes at high level
No. 4 lead de-energizes at high level
Low level reed switch
No. 2 lead is common
No. 3 lead energizes at low level
No. 1 lead de-energizes at low level
NOTE: Use extreme care in handling the reed switches during wiring
and adjustment procedures.
9
48-630 APM Pneumatic Control for Boiler Feed System Applications
2.3.2.3 Adjustment Procedure
Prior to adjusting the reed switches, the APM controller
should be calibrated to obtain the desired pneumatic
proportional band and level position adjustment.
After wiring the reed switches to the device to be operated,
they may be adjusted manually to actuate at the desired
high and low liquid level positions. Move the liquid indicator by hand to the desired low level actuating point on
the indicator scale.
NOTE: Scale readings are expressed in percent of displacer length.
Hold the indicator at the desired low level actuating point.
Turn the left hand adjuster screw until the reed switch
actuates.
The high level reed switch is adjusted in the same manner
by moving the level indicator to the desired high level actuating point, and by turing the right hand adjuster screw
until the high level reed switch actuates. See Figure 11.
Figure 10
2.4
Field Modifications and Adjustments
2.4.1 Changing Controller Action
The controller can be changed from direct acting to reverse
acting or vice versa. Should it be required to change the
controller action, refer to step 2 in Section 2.3.1,
Proportional Controllers on page 6.
Reed Switch
Adjuster
Screw
Magnet
Attractor
Pivoted
Magnet
2.4.2 Pneumatic-to-Current (P/I) Converter
APM units are available with a P/I transducer to provide
an electronic output signal proportional to liquid level
change. Refer to the manufacturer's instructions supplied
with the transducer.
Liquid Level
Indicator Scale
Non-Magnetic
Enclosing Tube
Level Sensing
Displacer
Figure 11
48-630 APM Pneumatic Control for Boiler Feed System Applications
10
3.0
Reference Information
3.1
Troubleshooting
3.1.1 Installation
The magnet carriage assembly binds at either the
magnet or the indicator scale.
1. The magnet binds on the enclosing tube. Loosen the retaining screw on magnet bracket and adjust the magnet alignment.
2. The carriage binds on the indicator scale. Check for
damaged, bent, or loose parts.
3. Check for proper mounting of the controller head.
3.1.2 Calibration
Signal pressure does not change with simulated level
change or unit won't calibrate properly.
1. Make certain the output gauge is operational.
2. Make certain the supply gauge reads 20 psig for
3–15 models or 35 psig for 6–30 models.
3. Check for proper calibration settings, refer to appropriate
calibration instructions on pages 6 through 8.
4. Check the proportional band and level settings for proper
process specific gravity. Refer to Figure 9 on page 8 for
settings corresponding to process specific gravities other
than 1.0.
5. The level indicator should be set for the proper process
temperature.
Cannot obtain proper midspan output (9 psig for 3–15
models or 18 psig for 6–30 models).
1. Adjust the zero adjustment screw.
2. Check if reset is included, the output signal will not be steady.
Constant high output (pressure does not drop after
manually moving the carriage so that the flapper drops
away from the nozzle).
1. Clogged exhaust nozzle from contamination or poor quality air supply. Clean nozzle by removing the small screw on
the top of the nozzle and blow out any foreign material, or
run fine monofilament type line through the opening.
2. Damaged or bent flapper spring. The flapper should stroke
approximately 1⁄16 inch away from the nozzle in the free hanging position. If it does not, carefully bend the spring down
with a screwdriver forcing the flapper away from the nozzle.
3. Obstructed output. Check connection at signal output.
11
48-630 APM Pneumatic Control for Boiler Feed System Applications
1.
2.
3.
4.
Constant low output, cannot obtain full scale signal.
Check for a clogged relay/wiper by depressing the orifice
clean out plunger. If this does not solve the problem, the
relay may be internally damaged. Consult the factory.
Check for proper supply pressure, described above.
Check for leaks at all field connections and tubing.
Check calibration settings.
3.1.3 Operation
Control valve continually oscillates or hunts.
1. Proportional band setting is too narrow. To ensure that the
optimum proportional band setting has been made, create
a momentary load upset by manually moving the magnet
carriage and allowing the controller to again come into
balance. If a cyclic condition recurs, widen the band slightly
and repeat the above procedure until stability is maintained.
2. Distance between the control valve and APM controller is
too great (time lag). Install volume booster in the signal line.
No output change as level changes.
1. Check that all gasketed joints on the relay are tight.
2. Check for leaks.
3. Depress relay/wiper plunger since the orifice may be plugged.
4. Remove the enclosing tube and inspect it for internal
buildup.
5. Unbolt the head assembly and check for displacer
interference.
6. Remove parts from the head assembly and inspect internal
components.
7. Consult factory.
8. Check sizing and operation of control valve. An oversized
valve or excessive friction are possibilities.
9. Check the output capacity. Controllers tend to be unstable
when dead-ended due to their high degree of sensitivity.
This condition is particularly aggravated when coupled
with 1 and 8 above.
48-630 APM Pneumatic Control for Boiler Feed System Applications
12
3.2
Specifications
3.2.1 Models APM-131, APM-W251, APM-W254 and APM-W291 Dimensional Specifications
inches (mm)
7.69
(195)
3.85
(98)
7.69
(195)
3.85
(98)
11.25
(285)
21/2" NPT
A
E
Adjustable
6.00 (152) to
120.00 (3048)
14.75
(374)
C
B
Span
adjustable
2.80 (71)
to
14.00 (355)
D
2.00
(50)
Figure 13
Figure 12
APM-W251, APM-W254, and APM-W291
APM-131
8.38
(213)
Swing radius
6.75
(171)
Catalog
Number
A
APM-W251
25.62
APM-W254
29.50
APM-W291
30.50
1/4" NPT
supply
Vent
.63 (16)
1/4" NPT
output
2.00 (51)
B
C
D
Gauge
Drum
Mid
glass
connector
range
centers
centers
of
and
and
throttling
pipe size pipe size
band
13.50
NPT
15.00
3⁄4" NPT
15.00
3⁄4" NPT
1⁄2"
13.50
1" NPT
16.00
11⁄4" NPT
15.00
11⁄4" NPT
6.00
8.00
7.50
E
Try-Cock
tappings
and
pipe
size
Three
NPT
Six
3⁄4" NPT
Three
3⁄4" NPT
1⁄2"
Dimensions are in inches and subject to change without notice. Certified
and detailed submittal drawings are available from the factory.
Figure 14
Controller Head (side view)
13
48-630 APM Pneumatic Control for Boiler Feed System Applications
;;;
;;;
;;;
;;
;;
3.3
Replacement Parts
Controller mechanism
20
15
14
1
10
2
4
13
7
3
11
12
6
5
8
9
19
18
3.3.1 Model APM-131 Parts Identification
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Description
Enclosing tube
Gasket (E-tube)
Spacer tube
Mounting bushing
Snap ring
Stop washer
Range spring
Connecting link
Lock nut
Spring cup (upper)
Screw
Spring cup (lower)
Retaining bracket
Jam nut
Attraction ball & stem assembly
Displacer
Clamp screw
Displacer cable
Connector nut
Controller case only
17
3.3.1.1 Model APM-131 Part Number
16
Enclosing tube
Gasket (E-tube)
Mounting bushing kit
(includes items 2 through 5)
Stem and spring kit
(includes items 5 through 15)
Displacer kit
(includes items 16 through 19)
Controller case only
Z32-6201-006
12-1204-001
89-5703-001
89-5505-001
89-6106-001
46-1505-001
Figure 15
Typical Top Mounting
Head Assembly
48-630 APM Pneumatic Control for Boiler Feed System Applications
14
3.3
Replacement Parts
3.3.2 Models APM-W251, APM-W254 and APM-W291 Parts Identification
1
2
6
3
5
4
12
8
11
10
7
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Description
Enclosing tube C.S.
Enclosing tube gasket
Head flange kit
Head flange gasket
Studs
Hex nuts
Head flange gasket
Spring mounting plate
Jam nut (not shown)
Cotter pin
Spring cup
Spring & stem assembly
Attraction sleeve (not shown)
Screws (not shown)
Chamber assembly
Displacer
Chamber liner (not shown)
Filter regulator (not shown)
Gauge (not shown)
Controller case only (shown on page 14)
15
16
Figure 16
Typical Carbon Steel Fabricated
External Cage Assembly
IMPORTANT:
When ordering replacement parts, please specify:
15
A. Model and serial number of receiver controller.
B. Name and number of replacement assembly (kit).
48-630 APM Pneumatic Control for Boiler Feed System Applications
3.3
Replacement Parts
3.3.3 Models APM-W251, APM-W254 and APM-W291 Parts Numbers
3.3.3.1 Model APM-W251 Part Number
3.3.3.2 Model APM-W254 Part Number
Enclosing tube C.S.
Enclosing tube gasket
Head flange kit
(includes items 3 through 6)
Stem and spring kit
(includes items 7 through 14)
Cotter pin
Chamber assembly
Displacer
Chamber liner (not shown)
Filter regulator (not shown)
Gauge (not shown)
Controller case only
(shown on page 14)
Enclosing tube C.S.
Enclosing tube gasket
Head flange kit
(includes items 3 through 6)
Stem and spring kit
(includes items 7 through 14)
Cotter pin
Chamber assembly
Displacer
Chamber liner (not shown)
Filter regulator (not shown)
Gauge (not shown)
Controller case only
(shown on page 14)
Z32-6201-006
12-1204-001
89-4202-001
89-5320-001
10-5202-005
89-4607-001
Z07-5422-001
89-4403-001
06-9501-002
06-9501-003
46-1505-001
Z32-6201-006
12-1204-001
89-4202-001
89-5320-001
10-5202-005
89-4608-001
Z07-5421-121
89-4404-001
06-9501-002
06-9501-003
46-1505-001
3.3.3.3 Model APM-W291 Part Number
Enclosing tube C.S.
Enclosing tube gasket
Head flange kit
(includes items 3 through 6)
Stem and spring kit
(includes items 7 through 14)
Cotter pin
Chamber assembly
Displacer
Chamber liner (not shown)
Filter regulator (not shown)
Gauge (not shown)
Controller case only
(shown on page 14)
Z32-6201-006
12-1204-001
89-4203-001
89-5320-001
10-5202-005
Z33-1004-001
Z07-5421-121
N/A
06-9501-002
06-9501-003
46-1505-001
48-630 APM Pneumatic Control for Boiler Feed System Applications
16
3.3
Replacement Parts
3.3.4 Controller Parts
17
3
1
32
11
16
15
33
24
23
2
13
12
34
34
18
19
20
21
22
4
6
8
3
7
7
9
5
4
10
Figure 18
Controller Replacement Parts
17
48-630 APM Pneumatic Control for Boiler Feed System Applications
3.3
Replacement Parts
3.3.5 Controller Parts Identification
32
26
25
27
28
29
30
29 **
31
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Qty
2
1
2
2
1
1
4
2
1
1
1
1
1
1
1
1
2
1
1
1
1
Description
Compression ring
Tube, 2.25" length ➀
Tube, 4.75" length ➀
Tube, 7.75" length ➀
Tube, 3.13" length ➀
Barbed tee
Barbed elbow
Tube elbow
Silicone tape, 1.25" length
Silicone tape, 2" length
Silicone tape, .75" length
Cable clamp
#10-32 x .25 round head screw
Tube, 30" length ➀
Nozzle lever assembly
Plate
#4-40 x .25 round head screw
Adjustment screw
Selector cam
Spring washer
22
23
24
1
1
1
25
26
1
1
Magnet carriage assembly
Palnut
Nameplate
Feedback assembly
Supply gauge
Output gauge
Gasket
O–ring, Viton®
27
28
29
30
31
32
33
1
1
2
1
1
1
1
O–ring, Viton®
O–ring, Viton®
O–ring, Viton® ➁
Gasket
Gasket, Relay mtg.
Wiper assembly
Relay assembly
Figure 19
NOTE:
➀ Customer is to cut tube lengths to correspond to those previously
supplied on the unit.
IMPORTANT:
When ordering replacement parts, please specify:
➁ Used only when mating surface has counterbore, otherwise discard.
A. Model and serial number of receiver controller.
B. Name and number of replacement assembly (kit).
48-630 APM Pneumatic Control for Boiler Feed System Applications
18
3.3
Replacement Parts
3.3.6 Controller Part Number
3–15 psig
Tubing kit
(includes items 1 through 14)
Nozzle lever kit
(includes items 1 and 3; 11 through 13; 15 through 17)
Carriage assembly kit
(includes items 19 through 22)
Feedback assembly kit
(includes items 1 through 2 and 23 through 24)
Supply gauge
Output gauge
Gasket kit for relay assembly
(includes items 25 through 31)
Wiper assembly
Relay assembly
6–30 psig
89-8501-015 or 89-8501-001 ➀
89-8501-002
89-8501-003
89-8501-005
89-8501-006
06-8112-030
06-8112-030
89-8501-004
89-7833-001
89-7803-001
NOTE:
➀ Use tubing kit 89-8501-015 for units with brass fittings. Use tubing kit
89-8501-001 for units with the plastic fittings (items 6, 7, and 8) and
process temperature below +450° F (+232° C). Consult factory for units
with plastic fittings and process temperatures above +450° F (+232° C).
IMPORTANT:
When ordering replacement parts, please specify:
19
A. Model and serial number of receiver controller.
B. Name and number of replacement assembly (kit).
48-630 APM Pneumatic Control for Boiler Feed System Applications
3.4
Model Numbers
3.4.1 APM Pneumatic Control Models
DESIGN TYPE
APM
Pneumatic Liquid Level Controls
MOUNTING AND MATERIALS OF CONSTRUCTION
Model
Code
Output
Signal
Mounting
Arrangement
Body
Material
Maximum
Pressure
Maximum
Temperature
Minimum
S.G.
Displacer
Size
131L
3–15
Top
Carbon steel
230 psig
(16 bar)
+250° F
(+120° C)
0.90
2" x 14"
131H
6–30
Top
Carbon steel
230 psig
(16 bar)
+250° F
(+120° C)
0.90
2" x 14"
W251
3–15
6–30
External
Flange Cage
Cast iron
250 lb. WSP
+406° F
(+208° C)
0.86
2.5" x 9"
W254
3–15
6–30
External
Flange Cage
Cast iron
250 lb. WSP
+406° F
(+208° C)
0.86
2" x 12"
W291
3–15
6–30
External
Flange Cage
Carbon steel
300 lb. WSP
+422° F
(+217° C)
0.85
2" x 12"
PNEUMATIC INSTRUMENT
Function
Proportional
A
P
Pressure
psig
3–15
6–30
Single Function Models
Direct Acting
Reverse Acting
Standard
w/Limit
Standard
w/Limit
Head
Switches
Head
Switches
PAA
PIA
PEA
PMA
PAB
PIB
PEB
PMB
M
48-630 APM Pneumatic Control for Boiler Feed System Applications
20
ASSURED QUALITY & SERVICE COST LESS
Service Policy
Return Material Procedure
Owners of Magnetrol/STI controls may request the return
of a control or any part of a control for complete rebuilding or replacement. They will be rebuilt or replaced
promptly. Controls returned under our service policy
must be returned by Prepaid transportation.
Magnetrol/STI will repair or replace the control at no cost
to the purchaser (or owner) other than transportation if:
So that we may efficiently process any materials that are
returned, it is essential that a “Return Material
Authorization” (RMA) number be obtained from the
factory, prior to the material's return. This is available
through Magnetrol’s or STI’s local representative or
by contacting the factory. Please supply the following
information:
1. Returned within the warranty period; and
2. The factory inspection finds the cause of the claim
to be covered under the warranty.
If the trouble is the result of conditions beyond our control; or, is NOT covered by the warranty, there will be
charges for labor and the parts required to rebuild or
replace the equipment.
In some cases it may be expedient to ship replacement
parts; or, in extreme cases a complete new control, to
replace the original equipment before it is returned. If
this is desired, notify the factory of both the model and
serial numbers of the control to be replaced. In such
cases, credit for the materials returned will be determined
on the basis of the applicability of our warranty.
1.
2.
3.
4.
5.
Company Name
Description of Material
Serial Number
Reason for Return
Application
Any unit that was used in a process must be properly
cleaned in accordance with OSHA standards, before it is
returned to the factory.
A Material Safety Data Sheet (MSDS) must accompany
material that was used in any media.
All shipments returned to the factory must be by prepaid
transportation.
All replacements will be shipped F.O.B. factory.
No claims for misapplication, labor, direct or consequential damage will be allowed.
5300 Belmont Road • Downers Grove, Illinois 60515-4499 • 630-969-4000 • Fax 630-969-9489 • www.magnetrol.com
145 Jardin Drive, Units 1 & 2 • Concord, Ontario Canada L4K 1X7 • 905-738-9600 • Fax 905-738-1306
Heikensstraat 6 • B 9240 Zele, Belgium • 052 45.11.11 • Fax 052 45.09.93
Regent Business Ctr., Jubilee Rd. • Burgess Hill, Sussex RH15 9TL U.K. • 01444-871313 • Fax 01444-871317
5300 Belmont Road • Downers Grove, Illinois 60515-4499 • 630-969-4028 • Fax 630-969-9489 • www.sticontrols.com
Copyright © 2005 Magnetrol International, Incorporated. All rights reserved. Printed in the USA.
Magnetrol and Magnetrol logotype are registered trademarks of Magnetrol International.
STI and STI logotype are registered trademarks of Magnetrol International.
Performance specifications are effective with date of issue and are subject to change without notice.
The brand and product names contained within this document are trademarks or registered trademarks of their respective holders.
Viton® is a registered trademark of DuPont Performance Elastomers.
BULLETIN: 48-630.8
EFFECTIVE: August 2004
SUPERSEDES: June 2003