Rosemount HAGAN 2½ x 5 Thrust Type, Swivel Mounted Pneumatic Power Positioner-Rev 1.0 Manuals & Guides

HAGAN 2-1/2 x 5
THRUST TYPE, SWIVEL
MOUNTED PNEUMATIC
POWER POSITIONER

Instruction Bulletin IB-102-202N Rev. 1

PAGE SUMMARY

HIGHLIGHTS OF CHANGES

Effective May, 1995 Rev. 1

3-0

3-1

6-1

Figure 3-1. Aded a callout regarding placement of positioner arm in relation to pilot valve.

Added paragraph 3-2. Mounting, regarding the correct positional relationship of the arm, calibration
spring, and pilot valve.

Tables 6-1 and 6-2. Added "Maintenance Tool Kit" to both lists of recommended spare parts.

IB-102-202N

ROSEMOUNT WARRANTY

Rosemount warrants that the equipment manufactured and sold by it will, upon shipment, be free of
defects in workmanship or material. Should any failure to conform to this warranty become apparent during
a period of one year after the date of shipment, Rosemount shall, upon prompt written notice from the
purchaser, correct such non-conformity by repair or replacement, F.O.B. factory of the defective part or parts.
Correction in the manner provided above shall constitute a fulfillment of all liabilities of Rosemount with
respect to the quality of the equipment.

THE FOREGOING WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER
WARRANTIES OF QUALITY WHETHER WRITTEN, ORAL, OR IMPLIED (INCLUDING
ANY WARRANTY OF MERCHANTABILITY OF FITNESS FOR PURPOSE).

The remedy(ies) provided above shall be purchaser's sole remedy(ies) for any failure of Rosemount to
comply with the warranty provisions, whether claims by the purchaser are based in contract or in tort
(including negligence).

Rosemount does not warrant equipment against normal deterioration due to environment. Factors such
as corrosive gases and solid particulates can be detrimental and can create the need for repair or replacement
as part of normal wear and tear during the warranty period.

Equipment supplied by Rosemount Analytical Inc. but not manufactured by it, will be subject to the
same warranty as is extended to Rosemount by the original manufacturer.

At the time of installation it is important that the required services are supplied to the system. Experience
shows that systems installed and not supplied with services can be damaged either by the process or by the
external environment and Rosemount will not accept any responsibility for this consequence.

IB-102-202N

i

PURPOSE

The purpose of this manual is to provide a comprehensive understanding of the Hagan 2-1/2 Inch x 5 Inch

Power Positioner, components, functions, installation, and maintenance.

This manual is designed to provide information about the 2-1/2 x 5 standard and on/off type power
positioners. We recommend that you thoroughly familiarize yourself with the Overview and Installation
sections before installing your power positioner.

The overview presents the basic principles of the power positioner along with its performance,
characteristics, and components. The remaining sections contain detailed procedures and information
necessary for installation and servicing of the power positioner.

Before contacting Rosemount concerning any questions, first consult this manual. It describes most
situations encountered in your equipment's operation and details necessary action.

DEFINITIONS

The following definitions apply to WARNINGS, CAUTIONS, and NOTES found throughout this
publication.

Highlights an operation or maintenance
procedure, practice, condition, statement,
etc., that if not strictly observed, could result
in injury, death, or long-term health hazards
of personnel.

NOTE

Highlights an essential operation procedure,
condition, or statement.

Highlights an operation or maintenance
procedure, practice, conditions,
statement, etc., that if not strictly
observed, could result in damage to or
destruction of equipment, or loss of
effectiveness.

NOTE TO USERS

The number in the lower right corner of each illustration in this publication is a manual illustration number.
It is not a part number, and is not related to the illustration in any technical manner.

IB-102-202N

ii

TABLE OF CONTENTS

Section Page

Rosemount Warranty ......................................................... i

Purpose .................................................................. ii

I. OVERVIEW OF HAGAN 2-1/2 INCH X 5 INCH POWER POSITIONER

1-1. Scope ............................................................... 1-1

1-2. Package Contents ...................................................... 1-1

1-3. Equipment Description .................................................. 1-1

II. THEORY OF OPERATION

2-1. Standard Unit ......................................................... 2-1

2-2. On/Off Standard Option ................................................. 2-2

III. INSTALLATION AND ADJUSTMENTS

3-1. Location .............................................................. 3-1

3-2. Mounting ............................................................ 3-1

3-3. Air Connections ....................................................... 3-1

3-4. Wiring .............................................................. 3-1

3-5. Adjustment Of Standard Units ............................................ 3-2

3-6. Adjustment of On/Off Units ............................................. 3-4

3-7. Adjustment of Optional Limit Switches ..................................... 3-4

IV. TROUBLESHOOTING

4-1. Troubleshooting Standard Units ........................................... 4-1

4-2. Troubleshooting On/Off Units ............................................ 4-3

V. SERVICE AND NORMAL MAINTENANCE

5-1. Scheduled Maintenance of Standard Units .................................. 5-1

5-2. Scheduled Maintenance of On/Off Units .................................... 5-2

5-3. Repairs to Control Systems ............................................... 5-4

5-4. Repairs to Cylinder Assembly ............................................ 5-4

5-5. Installation of Limit Switches ............................................ 5-6

VI. RECOMMENDED SPARE PARTS ............................................ 6-1

VII. RETURNING EQUIPMENT TO THE FACTORY ............................... 7-1

INDEX .............................................................................. I-1

IB-102-202N

iii

LIST OF ILLUSTRATIONS

Figure Page

1-1 Standard 2-1/2 Inch x 5 Inch Power Positioner (Variable Position Pilot Valve Type) ....... 1-1

1-2 On/Off 2-1/2 Inch x 5 Inch Power Positioner (On/Off Standard Option,

Solenoid Valve Type) ....................................................... 1-2

2-1 Standard Power Positioner - Main Components .................................... 2-1

2-2 On/Off Power Positioner ...................................................... 2-3

3-1 Installation Dimensions ....................................................... 3-0

3-2 Mounting Pivot Base Assembly (Part No. 371763) ................................. 3-2

3-3 Standard Unit Adjustment ..................................................... 3-3

3-4 Limit Switch Option .......................................................... 3-4

4-1 Standard Unit, Exploded View ................................................. 4-4

5-1 Pilot Valve Assembly - Exploded View .......................................... 5-0

5-2 Solenoid Valve Assembly - Exploded View ....................................... 5-3

5-3 Limit Switch Installation ...................................................... 5-7

LIST OF TABLES

Table Page

4-1 Standard Unit Troubleshooting ................................................. 4-1

4-2 On/Off Unit Troubleshooting .................................................. 4-3

6-1 Recommended Spare Parts for the Standard Power Positioner ......................... 6-1

6-2 Recommended Spare Parts for the On/Off Power Positioner .......................... 6-1

6-3 Recommended Spare Parts for the Standard Pilot Valve Assembly ..................... 6-1

6-4 Bill of Materials for the 2-1/2 x 5 Power Positioner ................................. 6-2

IB-102-202N

iv

SECTION I. OVERVIEW OF HAGAN

2-1/2 INCH X 5 INCH POWER POSITIONER

1-1. SCOPE.

install, operate, maintain and service all models of the
Hagan 2-1/2 Inch x 5 Inch Thrust Type, Swivel
Mounted Power Positioner.

1-2. PACKAGE CONTENTS

comes completely assembled and carefully packaged to
prevent damage in shipping. Inspect the packaging
before removing the unit, and report any damage to the
shipping agent.

Carefully pull the unit lengthwise out of the box. Find
the packing list that is included in each shipment.
Check the items received against the packing list to
verify that the shipment is complete and correct. Make
sure that the signal range stamped on the pilot valve is
the one the packing list calls for. If a pivot base has
been ordered, make sure it is attached to the unit.
Check all items for damage.

1-3. EQUIPMENT DESCRIPTION

a. Purpose

This manual gives information needed to

.

The power positioner

.

.

The Hagan Power Positioner is typically
used to position the damper of a large volume
boiler. To do this, the power positioner connects to
a lever on the damper jackshaft. The jackshaft
connects to the damper. When the power
positioner moves, the lever moves the jackshaft,
which moves the damper.

The difference between the two positioner types is
in the control power air system.

1. The Standard Power Positioner, Figure 1-1,
uses a variable, low pressure control air
circuit and a pilot valve assembly to control
the single pressure power air. The higher the
control air pressure, the farther the piston
extends. With this type of equipment, boiler
controls can move the power positioner to
any point along its five inch stroke.

b. Operation

positioners available: the standard variable
position pilot valve type, and the on/off standard
option with a solenoid valve. Both use the same
power components. In both types, power air
pressure moves a piston in a cylinder. When air
flow goes to the bottom of the cylinder the piston
moves upward. When air flow goes to the top of
the cylinder, the piston moves downward. As the
piston travels, a clevis (attached to the piston rod)
moves the damper lever.

.

There are two types of power

Figure 1-1. Standard 2-1/2 Inch x 5 Inch Power

Positioner (Variable Position Pilot Valve Type)

IB-102-202N

1-1

2. The On/Off Standard Option, Figure 1-2, uses
electrical signals and a solenoid valve to
control power air. The piston stops travel
only at fully extended or fully retracted
positions. The power positioner stays in
position until the solenoid valve is electrically
shifted. This makes the on/off type the best
choice in applications where the damper must
stay in position during an electrical power
failure.

See Section II, Theory of Operation, for detailed
explanations of the operation of both power
positioner models.

c. Limit Switch Option

.

Both the standard and
on/off power positioners are available with limit
switches. These limit switches signal the boiler
control system when the power positioner is at the
fully extended or fully retracted position. This
option is available direct from the factory, or as a
kit for field installation.

Figure 1-2. On/Off 2-1/2 Inch x 5 Inch Power

Positioner (On/Off Standard Option,

Solenoid Valve Type)

IB-102-202N

1-2

S

685003

SECTION II. THEORY OF OPERATION

2-1. STANDARD UNIT.

a. General

.

Refer to Figure 2-1, Standard Power
Positioner - Main Components. The piston
assembly and power take-off clevis of the standard
power positioner move away from the mounting
pivot with an increase in control signal pressure.
Movement of the piston, which is equipped with
graphite impregnated teflon piston cups, begins
when the increasing control signal at

NOTE: AN ASTERISK (*) INDICATES ITEMS ARE

INCLUDED IN THE PILOT VALVE ASSEMBLY.

POSITIONER ARM

the pilot valve assembly causes the stainless steel stem
to move downward from the neutral setting. The pilot
valve assembly then directs power air through the
bottom tubing assembly to the bottom of the aluminum
cylinder and exhausts air at the other end of the
cylinder to atmosphere. The resulting pressure
difference across the piston moves it upward.

POWER TAKE-OFF CLEVIS

TOP HEAD ASSEMBLY

DIAPHRAGM

ASSEMBLY*

INPUT SIGNAL

(CONTROL AIR)

(CUSTOMER

SUPPLIED)

POWER AIR
(CUSTOMER

Figure 2-1. Standard Power Positioner - Main Components

CYLINDER

CALIBRATION

SPRING

SUPPLIED)

PILOT VALVE

ASSEMBLY

TEM AND SLEEVE ASSEMBLY*

TEFLON

PISTON CUPS

TOP TUBING ASSEMBLY

PISTON ASSEMBLY
(INCLUDES TEFLON CUPS)

BOTTOM TUBING
ASSEMBLY

MOUNTING PIVOT

IB-102-202N

2-1

As the piston moves upward, it raises the upper
end of the calibration spring. Tension in the spring
is the feedback force in the pilot valve assembly.
Piston movement continues until the spring force
equals the force from the control signal, restoring
the pilot valve stem to the neutral position. This
blocks the flow of power air to cylinder and
prevents further piston movement until signal
pressure changes again.

For each control signal pressure, the piston is at a
particular distance from the bottom of the cylinder.
At the minimum signal it is at the lowest point in
the cylinder. At the maximum signal it is at the
upper limit, a distance of 5 in. (127 mm) from the
lowest point. At any other signal, the distance from
the bottom of the cylinder is proportional to the
signal pressure. Full stroke time is two seconds or
less. Toggling of the piston rod at or near full
stroke is prevented by the large area guide
bearings which are set relatively far apart in the
top head assembly. The guide bearings are made
of sintered teflon.

b. Pilot Valve

.

The pilot valve is a force/balance
device. The pilot valve makes use of an external
calibration spring (connected to the positioner
arm), an internal dual-diaphragm assembly, and a
sleeve and stem assembly.

increase of the control signal pressure causes a
downward movement of the pilot valve diaphragm
assembly. This forces the stem downward,
uncovering ports in a stainless sleeve which permit
power air to flow into the lower end of the cylinder
and the air in the upper end to exhaust to
atmosphere. The piston moves upward, pulling on
the calibration spring. Tension in this spring
increases until it balances the force due to the
control signal acting in the diaphragm assembly.
The stem then returns to the neutral position and
blocks the ports in the sleeve, preventing further
movement of the piston.

With a decrease in control signal pressure, the
opposite actions occur. In this case, the force due
to the control signal becomes less than the force of
the calibration spring. The spring then pulls the
spring post and stem seat upward. The stem is
pushed upward by the spring in the pilot valve
assembly and uncovers ports which transmit
power air from the pilot valve to the top of the
cylinder and exhaust the bottom of the cylinder.
The piston then moves downward, reducing the
tension in the calibration spring until it balances
the force due to the lower control signal. The pilot
valve assembly stem will then be in the neutral
position again and prevent further movement of
the piston.

Pilot valve operation is determined by the
interaction of two primary forces:

1. A downward force developed by the control
signal as it acts upon the diaphragm
assembly.

2. An upward force created by the tension of the
calibration spring.

In operation, the pilot valve diaphragm assembly
moves up or down and repositions the stem when
the force of the calibration spring and the force
due to the signal pressure are not in balance.
Starting with the stem in the neutral position, an

2-2. ON/OFF STANDARD OPTION

a. General

.

On/off type power positioners, Figure 2­2, use the same cylinder and piston assembly as
the standard type positioner. The on/off type,
however, uses an electric solenoid assembly in
place of a pneumatic pilot valve.

The solenoid assembly allows pressurized air to
enter one end of the cylinder, while exhausting air
from the opposite end to atmosphere. During
operation, air pressure builds on one side of the
piston, forcing the piston to move toward the low
pressure side. Air from the low pressure side
simultaneously exhausts through a fitting on the
solenoid valve body.

.

IB-102-202N

2-2

SOLENOID B
LAST ENERGIZED

SOL B SOL B

SOLENOID A
LAST ENERGIZED

PRESSURE PRESSURE

EXHAUST EXHAUST

SOL A SOL A

NOTE: IF SOLENOID B WAS LAST ENERGIZED, THE PISTON

WILL BE FULLY EXTENDED. IF SOLENOID A WAS LAST
ENERGIZED, THE PISTION WILL BE FULLY RETRACTED.

AA

BB

SOLENOID B

PORT A

2-1/2 X 5
CYLINDER

EXHAUST

FITTING

Figure 2-2. On/Off Power Positioner

b. On/Off Solenoid Valve

.

A solenoid operated,
on/off valve controls air flow in the on/off
standard option to the Rosemount power
positioner. This system uses electrical impulses
instead of pilot air pressure to control main air
flow. There are only two positions for this type of
equipment: piston fully out, and piston fully

POWER AIR

PORT B

SOLENOID A

685004

in. Once in a position, the piston stays in that position
until the opposite solenoid is actuated. This means that
if power fails, the piston stays in the same position.
This feature makes the on/off type of valve the best
choice in a system in which the damper must stay in
place if power fails.

IB-102-202N

2-3

PLACE ARM

DIRECTLY ABOVE

PILOT VALVE.

5.50

(140)

MAX R 9/16 (14)

3.7

(94)

MAX WIDTH

C

L

LINKAGE
SHAFT

1-3/4

(45)

FOR CLEVIS MOUNT

C

CLEVIS PIN

L

MAX DIA

FOR PIN MOUNT

C

PIVOT PIN

L

1.50
(38)

1-1/2 (38)

THROAT

ARM

0.500 (12.7)

0.498 (12.65)

CLEVIS

ADJUSTMENT
9/16
(14)

2

(51)

1/4

1/4

(6)

(6)

PISTON ROD
MOVES OUTWARD
WITH INCREASE
INPUT SIGNAL
PRESSURE

5 STROKE

(127)

15-13/16

(402)

LEVER

C

'S MUST BE PARALLEL

L

WITHIN 2

CLEVIS HEIGHT CAN BE ADJUSTED

IN 1/2 TURNS ONLY FROM POSITION

SHOWN AND MUST BE REALIGNED

WITH ARM AND LOCKED-IN PLACE

0.69 R
(18)

o

BY MEANS OF LOCKNUT

MOUNTING
DETAILS

2-1/2

(64)

ALLOW FOR CLEARANCE

REQUIRED TO WITHDRAW

VALVE SLEEVE

C

L

0.501 (12.72)

0.502 (12.78)

PIVOT

0.750 (19)

0.755 (19.2)

2-1/4
(57)

NOTE: DIMENSIONS ARE IN

INCHES WITH MILLIMETERS
IN PARENTHESES.

Figure 3-1. Installation Dimensions

IB-102-202N

3-0

11/16

(18)

1/8 N.P.T.
TAP FOR
INPUT SIGNAL

1/8 N.P.T. TAP FOR
AIR SUPPLY
MAX 125 PSIG
(862 kPa GAUGE)

2-5/32

(56)

5/8

R

(16)

685005

SECTION III. INSTALLATION AND ADJUSTMENTS

3-1. LOCATION.

The positioner should be located in a
clean, dry area free of excessive shock and vibration,
with a continuous ambient temperature between 0° and
170°F (-18° and 77°C). It should be easily accessible
for servicing.

3-2. MOUNTING

.

Before installation, carefully note the
clearance dimensions and other mounting information
shown in Figure 3-1. As shown in this figure, the
positioner may be either clevis or pin mounted.

The positioner may be installed in any direction:
vertical, horizontal, or inverted, whichever is most
convenient. The mounting pivot base assembly (P/N

371763) is shown in Figure 3-2.

The power take-off clevis (Figure 3-1) should be
properly aligned in relation to the axis of the mounting
pivot. The center lines of the mounting pivot pin,
linkage clevis pin, and linkage shaft must be parallel
within two degrees.

Ensure that the arm anchoring the top of the large
calibration spring is placed directly above the pilot
valve, and that the spring is not twisted in such a way
that will allow the pilot valve stem to rub on the sides
of the casting.

b. On/Off Units

.

Connect power air to the 0.25 in.
NPT air tap on the valve body as shown in Figure
2-2. Copper tubing with a 1/4 in. OD and 0.035 in.
wall thickness is best. Note that the entire power
positioner assembly moves when the piston
extends. To keep this movement from stressing the
copper air line, coil three turns of the line near the
unit.

A shutoff valve and air filter should be provided in
the air supply line. The shutoff valve is necessary
to isolate the positioner when servicing it.
Recommended air supply pressure is 100 psi (689
kPa). Maximum air supply pressure is 125 psi
(862 kPa).

3-4. WIRING

.

All wiring must comply with local and

national electrical codes. Connections are designed for

0.50 in. conduit. Since the entire power positioner
moves when the piston extends, use flexible conduit
for all wiring. If the unit is likely to get wet, use liquid
tight flexible conduit.

a. Standard Units

.

Wiring is not necessary on a

standard unit with no limit switches.

3-3. AIR CONNECTIONS

a. Standard Units

.

assembly. Control signal and power air
connections, located in the pilot valve assembly,
are 1/8 in. NPT taps. Refer to Figure 3-1. On the
pilot valve the upper tap is for the input signal and
the lower one is for the air supply. Copper tubing
with 1/4 in. (6.35 mm) OD and 0.035 in. (0.89
mm) wall thickness is best. Note that the entire
power positioner assembly moves when the piston
extends. To keep this movement from stressing the
copper air lines, coil each air line three turns near
the unit.

A shutoff valve and air filter should be provided in
the air supply line. The shutoff valve is necessary
to isolate the positioner when servicing it.
Recommended air supply pressure is 100 psi (689
kPa). Maximum air supply pressure is 125 psi
(862 kPa). Minimum air supply pressure is 45 psi
(310 kPa).

.

Connect air to the pilot valve

IB-102-202N

3-1

Be careful when removing the retaining clip
to wire the solenoid valve. The retaining
clip will spring upward when it disengages.
This could cause injury.

Make sure that the solenoids and the
electrical source are the same type. AC
and DC solenoids are different internally
and will be damaged by the wrong
electrical current.

b. On/Off Units

.

Remove metal retaining clip (1,
Figure 5-2) and rotate solenoid backplate (8) to the
necessary position. Make the wiring connections
necessary for the control system. Then replace the
housing and nameplate and reinstall the retaining
clip.

685006

1/2 R

(13)

4 HOLES 13/32 O/(11)

C OF CYLINDER MUST NOT FALL

L

OUTSIDE OF THIS ZONE

o

60

1-5/16

(34)

1-13/16

(46)

1-5/16 (34)

C

L

1-5/16 (34)

1-13/16 (46)

1-5/16
(34)

3-5/8

(98)

C

1-1/2 (38)

3-5/8 (98)

PILOT VALVE

L

o

60

REQ.

NOTE: DIMENSIONS IN INCHES WITH

LINE

2

1
1

MILLIMETERS IN PARENTHESES.

1
2

3

NAME
"E" RING
CLEVIS PIN

PIVOT BASE

PAR T NO .

120079-10
171762

371738

60

o

1/2

(13)

BRACKET AND BOLTING

NOT BY HAGAN

Figure 3-2. Mounting Pivot Base Assembly

c. Limit Switches

.

To wire limit switches on either
type of unit, remove the cover plate that is held by
two screws, and wire the limit switches to the
system controls as necessary.

3-5. ADJUSTMENT OF STANDARD UNITS

standard power positioner must be adjusted so the
piston is at the lower limit when the control signal is at
minimum pressure, and moves to the upper limit when
the signal is increased to maximum pressure.

(Part No. 371763)

Refer to Figure 3-3 and use the following procedure to make
the adjustment:

.

The

a.

Disconnect the mechanical linkage from the clevis.

b.

With the control (input) signal and power air
supply lines disconnected from the pilot valve,
clean the lines with high pressure air.

IB-102-202N

3-2

POSITIONER

Ca

Number of active coils
required

=

x

Pa

Pm

ARM

MECHANICAL
LINKAGE

CLEVIS

SET SCREW

PISTON ROD

6. Lock this setting by tightening the set screw
until the positioner arm binds to the piston
rod.

f.

With the piston at the bottom of the cylinder, place
a mark on either the clevis or the 1/2-in. diameter
chrome plated piston rod. The mark is for use in
measuring the piston stroke. If the stroke is not
correct, increase or decrease the number of active
coils in the calibration spring. Active coils are
those which are free of the positioner arm and
which flex when under load.

CALIBRATION

SPRING

CONTROL

SIGNAL

LINE

POWER AIR

SUPPLY LINE

PILOT

VALV E

BOTTOM
CYLINDER
HEAD

Figure 3-3. Standard Unit Adjustment

c.

Open the air supply filter drain and blow out
accumulated moisture and foreign particles.

d.

Reconnect the control signal and power air supply
lines. Adjust power air supply pressure to desired
value.

e.Apply minimum control signal to the pilot valve.

The piston should move to the lowest position,
against bottom cylinder head. Check this in the
following manner:

1. Maintain minimum control signal on the pilot
valve.

2. Loosen the set screw on the positioner arm.

685007

Determine stroke by increasing control signal
pressure slowly and observing travel of the mark
(discussed in preceding paragraph).

1. If the piston moves to upper limit before the
control signal reaches maximum pressure, the
number of active coils must be decreased as
described in step g.

2. If piston travel is less than desired when
maximum signal is applied, the number of
active coils must be increased as described in
step h. Maximum travel is approximately 5
in. (127 mm).

3. If piston stroke is satisfactory, perform steps
i, j and k.

g.

To decrease the number of active coils, use the
following procedure:

1. Reduce control signal to zero.

2. Count the active coils of calibration spring.
Active coils are those which are free of the
positioner arm and which flex when under
load.

3. Determine the exact control signal pressure at
which the piston reaches upper limit.

4. Determine the number of active coils required
by using the following equation:

3. Move the positioner arm up until the piston
moves to the bottom of the cylinder.

Where:

4. Move the positioner arm down until the
piston begins to move upward.

Pa = Signal pressure at which piston

reaches upper limit

5. Move the positioner arm down until the
piston just returns to lowest position.

Pm = Maximum control signal pressure

to be used

Ca = Actual number of active coils

IB-102-202N

3-3

5. Reduce active coils to the number required by
turning the calibration spring further onto the
positioner arm.

6. Repeat step f to check the stroke again.

h.

To increase the number of active coils, use the
following procedure:

1. Reduce control signal to zero.

2. Count active coils of calibration spring.
Active coils are those which are free of the
positioner arm and which flex when under
load.

3. Determine exact piston stroke by measuring
amount of travel of the mark (on piston rod or
clevis) when control signal is increased from
zero to maximum pressure.

4. Determine the number of active coils required
by using the following equation:

3-7. ADJUSTMENT OF OPTIONAL LIMIT

SWITCHES.

Refer to Figure 3-4. Adjust the upper
limit switch so the switch striker activates the switch
when the piston reaches its fully extended limit. Adjust
the lower limit switch so the striker activates the switch
when the piston reaches its fully retracted limit. Adjust
the switches as follows:

a.

Observe the limit switches while running the
power positioner. Each switch should activate just
as the piston reaches its mechanical limit, and
switch off as the piston begins to move in the other
direction.

b.

To adjust a limit switch, loosen the switch
mounting screws to allow the switch assembly to
slide on its bracket. Slide switch assembly as
necessary, then retighten the screws. Watch the
switch again while running the positioner.
Readjust as necessary.

Sr
Sa

x

Number of active coils

=

Ca

required

Where:

Sa = Actual stroke
Sr = Required stroke
Ca = Actual number of active coils

5. Increase the number of active coils by turning
spring off of the positioner arm.

6. Repeat step f to see if desired stroke is
obtained.

i.

Repeat step c to check minimum setting again.

j.

Check mechanical linkage between the positioner
and the damper or valve that the positioner
positions. All links must be properly aligned.

k.

Reconnect mechanical linkage to clevis.

3-6. ADJUSTMENT OF ON/OFF UNITS

adjustment of on/off units.

.

There is no

UPPER

LIMIT

SWITCH

MOUNTING

SCREW

SWITCH

STRIKER

LOW LIMIT

SWITCH

SWITCH

BRACKET

Figure 3-4. Limit Switch Option

IB-102-202N

3-4

SECTION IV. TROUBLESHOOTING

4-1. TROUBLESHOOTING STANDARD UNITS.

The four most common causes of poor operation of the
standard power positioner are listed below. Check if
any of these conditions exist and make corrections, if
necessary, before starting any repairs. If none of these
conditions apply, Refer to Table 4-1, Standard Unit
Troubleshooting.

a.

Air supply pressure is below normal. Check for the
following conditions:

1. Complete loss of air supply or less than
normal air supply pressure.

2. Air supply to the positioner shut off at a valve
or cut off due to a change or break in the
piping.

Table 4-1. Standard Unit Troubleshooting.

Unless otherwise indicated, item numbers are in reference to Figure 4-1.

NOTE

3. Pressure reducing valves in the system
incorrectly adjusted.

4. Air filters restricting flow due to dirty
elements. Blow down all filters.

b.

Plugged signal or air supply line. Check that all
lines are clean. Clear out any foreign material
which may be blocking them.

c.

Leaks in signal lines, air supply lines and tubing
assemblies. Go over each joint and connection in
these lines with soap suds to check for air leaks.
Stop any leaks found.

d.

Excessive friction at mounting pivot, clevis and
associated mechanical linkage. Check that these
points are well oiled, not binding, or otherwise
inhibited.

SYMPTOM CAUSE SOLUTION

1. Erratic operation along with one of the
following:

a. Piston moves in a jerky manner. a. Sticky material on inside of

a. Clean cylinder walls.

cylinder wall.

b. Piston fails to move to desired

position quickly when signal

b. Stem (15, Figure 5-1) sticking

due to gummy deposits.

b. Clean stem and sleeve.

changes.

c. Power air [100 psi (689 kPa)]

continuously blowing through

c. Stem (15, Figure 5-1)

excessively worn.

c. Replace stem and sleeve.

exhaust ports of pilot valve
assembly.

IB-102-202N

4-1

Table 4-1. Standard Unit Troubleshooting (Continued).

NOTE

Unless otherwise indicated, item numbers are in reference to Figure 4-1.

SYMPTOM CAUSE SOLUTION

2. Piston does not move full stroke when
maximum signal is applied and one of
the following symptoms is present:

a. No other symptoms. a. Too few active coils in

calibration spring (8).

a. Increase number of active coils

in spring (8). Refer to paragraph

3.5.h.

b. Signal air [15, 30, or 60 psi (103,

207, or 414 kPa)] continuously

b. Broken diaphragm in pilot

valve assembly.

b. Replace broken diaphragm.

leaking from exhaust ports of pilot
valve assembly (27).

c. Power air [100 psi (689 kPa)]

c. Piston cups (22) worn. c. Replace both piston cups.
blowing continuously through
exhaust ports of pilot valve
assembly (27).

3. Piston does not return to bottom of
cylinder when signal is zero and one
of the following symptoms is present:

a. No other symptoms. a. Positioner requires adjustment. a. Perform Adjustments of

Standard Units, paragraph 3-5.

b. Power air leaking past piston rod

b. Piston rod seal (12) worn. b. Replace piston rod seal.

(5) at seal retainer (11).

c. Power air continuously blowing

c. Piston cups (22) worn. c. Replace both piston cups.
out of exhaust ports of pilot valve
assembly (27).

IB-102-202N

4-2

4-2. TROUBLESHOOTING ON/OFF UNITS.

Table 4-2, On/Off Unit Troubleshooting, for a listing
of possible symptoms, causes and solutions for

Refer to

problems with an on/off type power positioner.
Cylinder and piston assembly parts are identical to
those of the standard unit (Figure 4-1).

Table 4-2. On/Off Unit Troubleshooting.

NOTE

Unless otherwise indicated, item numbers are in reference to Figure 5-2.

SYMPTOM CAUSE SOLUTION

1. Erratic operation along with one of
the following:

a. Piston moves in a jerky manner. a. Sticky material on inside of

cylinder wall.

b. Piston fails to move to desired

position quickly when solenoid

b. Core subassembly (12) sticking

due to gummy deposits.

changes.

c. Power air [100 psi (689 kPa)]

continuously blowing through

c. Valve (18) or piston cups (22,

Figure 4-1) excessively worn.
exhaust ports of solenoid valve
assembly.

2. Piston does not move full stroke
when solenoid is energized and one
of the following symptoms is
present:

a. No other symptoms. a. Open or burned out coil (6) in

solenoid.

Faulty control circuit.

b. Excessive leakage at solenoid

valve.

b. Worn or damaged parts in

solenoid valve assembly.

a. Clean cylinder walls.

b. Clean core subassembly.

c. Replace worn components.

a. Check continuity of coil. Replace

if necessary.

Energize solenoid; listen for
metallic click. No click means no
voltage.

b. Replace solenoid valve

assembly.

3. Piston does not return to bottom of
cylinder when opposite solenoid is
energized.

Replacement parts for the solenoid valve assembly are available from ASCO Valves at the
following address:

a. Open or burned out coil (6) in

solenoid.

Faulty control circuit.

NOTE

ASCO Valves
Automatic Switch Co.
Florham Park, NJ 07932

IB-102-202N

4-3

a. Check continuity of coil.

Replace if necessary.

Energize solenoid. Listen for
metallic click. No click means no
voltage.

1

9

3

10

11

22

2

4

5

6

15

12

17

19

13

14

18

16

17

24

25

21

20

23

16

26

27

7

8

20

21

16

22

16

28

685009

Figure 4-1. Standard Unit, Exploded View

IB-102-202N

4-4

LEGEND FOR FIGURE 4-1

ITEM DESCRIPTION

1 Retaining Ring
2 Clevis Pin
3 Clevis
4 Hex Nut
5 Piston Rod
6 Positioner Arm
7 Socket Head Cap Screw
8 Calibration Spring

9 Cap Screw
10 Lock Washer
11 Seal Retainer
12 Seal
13 Hex Nut
14 Lock Washer

ITEM DESCRIPTION

15 Top Head Assembly
16 Elbow Fitting
17 Cylinder Head Gasket
18 Top Tubing
19 Cylinder
20 Garter Spring
21 Piston Cup Follower
22 Piston Cup
23 Bottom Tubing
24 Washer
25 Elastic Stop Nut
26 Bottom Cylinder Head
27 Pilot Valve Assembly
28 Tie-Rod

IB-102-202N

4-5

(NOTE 1)

2

1

EXHAUST PORT

(1 OF 2)

3

12

4

PORT TO
CYLINDER TOP (*)

SPRING POST

7

INPUT SIGNAL

PORT (*)

9

PORT TO
CYLINDER BOTTOM (*)

POWER

5

6

AIR

SUPPLY

PORT (*)

13

14

ITEM DESCRIPTION

1 Socket Head Cap Screw

15

2 Rubber Boot
3 Top Spring Retainer, Standard
4 Top Loading Spring

16

5 Top Diaphragm Seat
6 Top Diaphragm

17

8

7 Center Block
8 Center Diaphragm Post
9 Bottom Diaphragm

18

10 Bottom Diaphragm Seat
11 Top Stem Seat
12 Valve Body

10

11

685010

13 O-rings (4)
14 Sleeve
15 Stem
16 Bottom Stem Seat
17 Bottom Loading Spring
18 Sleeve Retainer

NOTE 1: 2-1/2 X 5 POWER POSITIONERS USING AN EPT REQUIRE A MODIFIED TOP SPRING RETAINER AND

A TOP DIAPHRAGM COVER IN PLACE OF ITEM (3). IN THE STANDARD PILOT VALVE ASSEMBLY A
TOP DIAPHRAGM COVER IS NOT USED.

NOTE 2: AN ASTERISK (*) INDICATES A 1/8 NPT TAPPED PORT.

NOTE 3: NOT ALL ITEMS IDENTIFIED ARE AVAILABLE FOR INDIVIDUAL SALE. SEE SECTION VI,

REPLACEMENT PARTS, FOR A LIST OF AVAILABLE PARTS.

Figure 5-1. Pilot Valve Assembly - Exploded View

IB-102-202N

5-0

SECTION V. SERVICE AND NORMAL MAINTENANCE

5-1. SCHEDULED MAINTENANCE OF

STANDARD UNITS.

Design and construction of the
standard power positioner greatly reduces routine
maintenance. Only the following components need
routine maintenance:

a. Air Supply

.

Drain the air line moisture trap daily.
Clean or replace the air filter as necessary,
depending on humidity, dust, and filter
manufacturer's specifications.

b. Linkage Components

.

Lubricate clevis pin (2,
Figure 4-1), customer-supplied mount pin, and
linkage between the positioner and the component
it controls every six months. Use a few drops of
light oil.

c. Sleeve and Stem

.

For normal operating
conditions in which a clean and dry supply of
compressed air is used, the pilot valve sleeve and
stem require inspection and cleaning every six
months.

The same procedure is necessary if the stem is
sticking. A sticking stem is indicated when the
piston fails to move quickly to the required
position during control signal changes. A worn
stem must also be replaced. It is indicated by
power air continuously blowing through the
exhaust ports in the pilot valve body. Refer to
Figure 5-1.

To clean and inspect the pilot valve, use the
following procedure:

4. Allow the stem to fall from pilot valve
assembly on its own. Be careful that it does
not fall on a hard surface. If stem will not fall
out on its own, remove sleeve and stem as an
assembly. The two can be separated on a
bench without much danger of bending the
stem.

5. Wash stem and sleeve with clean solvent. Do
not use any abrasive or sharp edged tools.
Dry sleeve with compressed air and wipe off
stem with a clean lint free cloth.

6. Check stem for straightness by rolling it on a
flat surface. If not perfectly straight, replace
the stem and the sleeve.

7. Insert stem into bore of sleeve. (Since stem is
symmetrical, it may be installed with either
end up.)

8. Check stem in bore of sleeve. Stem must fall
freely through sleeve by its own weight
(when both stem and sleeve are dry, clean,
and free of oil).

NOTE

Stem and sleeve must be replaced as a
complete assembly if stem is bent or if either
is worn.

1. Shut off power air supply to pilot valve
assembly.

2. Reduce control signal to zero.

NOTE

Many parts are small and may be easily lost
or misplaced.

3. Unscrew sleeve retainer (18, Figure 5-1).
Remove bottom loading spring (17) and
bottom stem seat (16). Be careful not to lose
stem, bottom stem seat and bottom loading
spring.

9. Check that O-rings (13) on sleeve (14) are in
good condition. Install new ones if necessary.

10. Install sleeve in pilot valve assembly.

11. Insert stem in sleeve and replace pilot valve
bottom stem seat (16), bottom loading spring
(17), and sleeve retainer (18). Turn sleeve
retainer in until it hits bottom of sleeve and
holds it firmly in place.

12. Turn on air supply pressure and reapply
control signal. Power positioner is then ready
for operation.

IB-102-202N

5-1

5-2. SCHEDULED MAINTENANCE OF ON/OFF

UNITS.

The on/off type power positioner requires
very little maintenance. Only the following three
components need scheduled maintenance:

a. Air Supply

.

Drain air line moisture trap daily.
Clean or replace the air filter as necessary,
depending on humidity, dust, and filter
manufacturer's specifications.

b. Linkage Components

.

Lubricate clevis pin (2,
Figure 4-1), mount pin and linkage between the
positioner and the component it controls every six
months. Use a few drops of light oil.

c. Solenoid Valve

.

If the air supply is clean and dry,
inspect and clean solenoid valve (18, Figure 5-2)
every six months, or if leaky, noisy or sluggish. To
do this, follow this procedure:

1. Depressurize valve (18) and turn off electrical
supply. Disconnect piping if that makes
access to the valve easier.

4. Slide core subassembly (12) toward cylinder
side of valve body. Remove detent

port B
(19) and detent washer (20) from core
subassembly. Remove core subassembly
through cylinder port A

side of valve body.

5. Remove discs (13), sleeve (14), and quad ring

gasket (15) from core subassembly.

6. Inspect all parts. Replace solenoid valve

assembly if worn or damaged.

7. Clean metallic parts with solvent and a stiff

non-metallic brush. Do not scratch parts or
remove any material.

8. Reinstall discs (13), sleeve (14), and quad

ring gasket (15) in core subassembly (12).

9. Lubricate inside walls of valve body and

solenoid base subassemblies with high grade
silicone grease. Carefully observing notes on
Figure 5-2, slide core subassembly into
cylinder port A

side of valve body.

Be careful when removing retaining clip. It
is spring loaded and will spring upward
when released. This could injure personnel.

2. Prevent retaining clip (1) from springing
away. Remove the retaining clip from each
side of the valve. Then remove each entire
assembled solenoid enclosure (items 3
through 8) from the solenoid base
subassembly.

3. Disassemble each solenoid by removing
bonnet screws (22), bonnet plates (9 and 23),
solenoid base subassembly (11), and body
gasket (17).

10. Push core subassembly far enough toward
cylinder port B

side to install detent (19) and
detent washer (20). Then install each body
gasket (17), solenoid base subassembly (11),
upper bonnet plate (9), lower bonnet plate
(23) and bonnet screws (22).

11. Reinstall both assembled solenoid enclosures
(items 3 through 8). Put on nameplates (2)
and secure each assembly with a retaining
ring (1).

12. Operate the valve a few times to make sure it
is working properly before returning power
positioner to service.

IB-102-202N

5-2

(18)

1

2

3

B

8

9

10

11

13

14

4

5

6

7

(NOTE 1)

12
(NOTE 2)

22

CYLINDER

PORT A

CYLINDER

PORT B

21

17

18

21

17

19

20

11

10

23

ITEMS 3-8

A

ASSEMBLED

2

15

16

NOTE 1: TORQUE TO 20 T O 25 IN-LBS (2 TO 3 N M).

NOTE 2: GROOVED END OF ITEM (12) MUST FACE SOLENOID "A" WITH

ITEM DESCRIPTION

1 Retaining Clip
2 Nameplate
3 Housing
4 Spring Washer
5 Insulating Washer

(Not on all units)
6 Coil
7 Insulating Washer

(Not on all units)

1

DETENT. ITEM (12) MUST BE INSERTED FROM PORT A-SIDE OF
ITEM (18). THE PASSAGEWAY IN ITEM (12) MUST BE ORIENTED
WITH THE PORTS OF ITEM

ITEM DESCRIPTION

8 Baseplate

9 Upper Bonnet Plate
10 Washer
11 Solenoid Base Subassembly
12 Core Subassembly
13 Disc
14 Sleeve

.

ITEM DESCRIPTION

17 Body Gasket
18 Valve Body
19 Detent
20 Detent Washer
21 Mounting Bracket
22 Bonnet Screw

23 Lower Bonnet Plate
15 Quad Ring Gasket
16 Disc

Figure 5-2. Solenoid Valve Assembly - Exploded View

IB-102-202N

5-3

5-3. REPAIRS TO CONTROL SYSTEM.

a. Replacement of Pilot Valve Diaphragms

to Figure 5-1. Diaphragms (6 and 9) in the pilot
valve assembly must be replaced if they are soft
and spongy, hard and brittle, or broken. A broken
diaphragm shows up as erratic operation of the
power positioner with the piston not moving to the
upper limit when the maximum signal is applied to
the pilot valve. If the break is large, considerable
signal air will be noticed continuously leaking
from the pilot valve assembly.

.

Re fer

7. Reassemble items (1) through (11) to valve
body (12). Only tighten screws (1) by hand at
this time.

8. Apply and maintain 10 psi (69 kPa) air
pressure between diaphragms through signal
input port.

9. Turn screws (1) alternately and in stops to a
torque of 2 ft-lbs (3 N

m).

•

10. Remove input signal air pressure.

Use the following procedure when inspecting and
replacing diaphragms.

1. Shut off air supply.

2. Reduce control (input) signal to positioner to
zero and disconnect input signal line at pilot
valve assembly.

3. Disconnect calibration spring from top
diaphragm seat spring post (5, Figure 5-1).

4. Remove socket head cap screws (1). Remove
items (2) through (11) as an assembled unit.

NOTE

Top stem seat (11) unthreads from top
diaphragm seat (5), allowing both
diaphragms (6 and 9) to be removed.

5. Remove top stem seat (11).

Excessive clamping pressure produced
by exceeding torque valve will damage
diaphragms. Do not exceed specified
torque valves.

11. Turn screws (11) alternately and in steps to a
torque of 4 ft-lbs (5 N

m).

•

12. Connect the calibration spring to spring post.

13. Remove the 10 psi (69 kPa) line and
reconnect the control signal line to pilot valve
assembly. Turn on air supply pressure. Power
positioner is then ready for operation.

b. Repairs To On/Off Control System

.

There are
no repairs authorized on the on/off control system
other than cleaning the solenoid valve
(paragraph 5-2c).

5-4. REPAIRS TO CYLINDER ASSEMBLY

(Standard and On/Off).

a. Replacement of Piston Rod Seal

.

Refer to
Figure 4-1. Excessive air leakage from the top
head assembly (15, Figure 4-1) past the piston rod
(5) indicates that the silicone seal (12) is worn and
must be replaced. The instructions below apply to
both standard and on/off type units. Where there is
a difference between the units, be sure to follow
instructions for the specific unit used. To replace
piston rod seal proceed as follows:

1. Move piston to bottom of cylinder by either
reducing control signal to zero (standard
units) or actuating solenoid A

. Then shut off

air supply.

6. Replace diaphragms if broken, hard and
brittle, or soft and spongy. Reassemble
diaphragm assembly with Loctite

TM

sealant

on threads of top stem seat (11). Torque

•

assembly to 1 to 1-1/2 ft-lbs (1 to 2 N

m).

IB-102-202N

2. Disconnect linkage at clevis (3, Figure 4-1).

3. On standard units only, mark the location of
positioner arm (6) on piston rod (5).
Disconnect lower end of calibration spring
(8) from pilot valve spring post.

5-4

4. On standard units, loosen clamping screw (7)
in arm (6).

5. Hold clevis and loosen locknut (4) with a
wrench. Unscrew clevis and locknut, and
remove the arm from the piston rod.

6. Unscrew cap screws (9), and remove
lockwasher (17), and seal retainer (11) to
expose seal (12).

7. In order to ease removal of seal, place one
layer of plastic electrical-type tape over
piston rod threads. Start tape at outer end of
piston rod and overlap it with raised edges
facing the same direction the seal is to be
removed. The tape should also be lubricated
with a coating of McLube

TM

MOS2-200

grease.

If graphite impregnated teflon piston cups (22)
wear to the extent that air leaks past the piston,
they should be replaced. This is indicated by
power air blowing continuously through the
exhaust openings of the pilot valve.

Before cleaning the cylinder walls or replacing the
piston cups, make sure there is no problem in the
control system. Both standard and on/off units can
operate like there is a piston cup problem when
their control system is dirty. Before replacing
piston cups, follow cleaning procedures in
paragraph 5-1.c. or 5-2.c. If this does not solve the
problem, proceed as follows:

NOTE

Unless otherwise indicated, item numbers
refer to Figure 4-1.

8. Slip seal off piston rod.

9. Before installing new seal, remove tape
installed in step 7. Retape threads in opposite
direction. Tape should be overlapped, with
raised, sharp edges facing downward so that
they will not scratch seal as it is pulled down
piston rod. Tape should also be lubricated
with a light coating of McLube

TM

MOS2-200

grease.

10. Install a new seal after lubricating it with
McLube

TM

MOS2-200 grease.

11. Reassemble power positioner, using
preceding steps in reverse order. Clevis and
arm must be properly aligned and located.
Use the mark made in step 3 when
reassembling arm (6) on standard units.

12. After reassembling unit, perform steps in
paragraph 3-5, Adjustment of Standard Units.
The positioner will then be ready for
operation.

b. Replacement of Piston Cups

.

If the piston moves
in a jerky manner, it is usually an indication of an
accumulation of sticky material on the inside walls
of the cylinder (19, Figure 4-1). For the positioner
to operate properly, the cylinder walls must be
clean.

1. Shut off all air supply. Disconnect electrical
power to on/off units.

2. Disconnect power and control air supply lines
to pilot valve assembly (27, Figure 4-1) or
solenoid valve assembly (Figure 5-2).
Disconnect mechanical linkage at clevis (3,
Figure 4-1).

3. Remove pivot pin through bottom cylinder
head (26) and place positioner on a work
bench.

4. On standard units, disconnect calibration
spring (8) from pilot valve.

5. Disconnect tubing connections from bottom
cylinder head (26).

6. Remove hex nuts (13), lockwashers (14), and
four steel tie-rods (28).

7. For on/off units, remove bottom cylinder
head (26).

8. On standard units, remove pilot valve
assembly (27) and bottom cylinder head (26).

9. Invert the remaining positioner assembly and
support it vertically by clamping clevis (3) in
a vise.

IB-102-202N

5-5

10. Remove cylinder (19) from piston assembly
by slowly turning the cylinder clockwise
while pulling it upward, away from top head
assembly (15).

(e) Hold top head assembly and pull

cylinder back over piston assembly until
piston is approximately half way into
cylinder.

11. Clean out bore of cylinder with a cloth soaked
in a solvent. Do not scrape with sharp tools or
use abrasive materials such as emery cloth.

12. Inspect piston cups (22). If worn, creased, or
scratched, they must both be replaced.

13. If piston cups require replacement, remove
locknut (25) and washer (14) from rod (5).
Two piston cup followers (21) and piston
cups may then be slipped off the end of the
piston rod.

Be careful that piston cups are not
creased or scratched during assembly.
Damaged piston cups will impair
positioner performance.

14. Reassemble piston assembly and insert it into
cylinder in the following manner:

(a) Assemble parts of piston on end of

piston rod, except outer garter spring
(20) and outer piston cup.

15. Remove positioner from vise. Pull top head
assembly along piston rod until it hits the end
of the cylinder. Reassemble positioner by
installing control system assembly and
bottom cylinder head at lower end of cylinder
and installing studs, lockwashers and nuts.

16. Connect tubing assemblies to bottom cylinder
head.

17. On standard units, connect calibration spring
to pilot valve assembly.

18. Mount positioner and connect linkage to
clevis. Connect power air supply and either
control air signal lines or electrical lines to
control system. Open control signal air or
close electrical power switch.

19. Turn on power air supply pressure. The
positioner is now ready for operation.

5-5. INSTALLATION OF LIMIT SWITCHES

following instructions cover the installation of a limit
switch kit onto either a standard or on/off type power
positioner.

a.

Check parts kit items against those of Figure 5-3.

.

The

(b) Turn locknut (25) until only finger tight.

(c) Check that gasket (17) is in place at top

head assembly and then slip cylinder
down over the piston assembly until
washer (24) is about 1/4 in. (6 mm)
from end of cylinder.

(d) Remove locknut (25), washer (24), and

outer piston cup follower (21). Install
outer piston cup (22), outer piston cup
follower (21) and garter spring (20);
reassemble entire piston. Tighten
locknut (25).

IB-102-202N

5-6

Shut off all air pressure and electricity to
power positioner, and remove and block
mechanical load before beginning this
procedure. Failure to do this could allow the
power positioner to move. This could injure
personnel or damage equipment.

b.

Orient power positioner as shown in Figure 5-3.
Clevis must be up, and pilot valve or solenoid
valve to the right.

4, 5, 6

c.

Assemble limit switches (1, Figure 5-3) and
brackets (3), using nut plate (7), flat washers (5),

C

lockwashers (6) and screws (4). Orient limit
switches as shown. Slide limit switches to
outermost point in slots. This is to prevent damage

7

B

1

from switch striker (2) before adjustment.

d.

Remove two tie-rods (A) from left side of
cylinder.

e.

Install bottom bracket (3) on tie-rods (A) and
insert tie-rods through cylinder heads. Install top

D, E

bracket, lockwashers (D) and nuts (E) on top of
tie-rods (A) and torque to 8 to 12 ft-lbs (11 to 16

•

m).

N

f.

Loosen nut (B) under clevis (C); remove clevis.
Install switch striker (2); reinstall clevis. Retighten
nut under clevis, making sure switch striker lines
up with switch actuator rollers.

g.

Connect wiring to limit switches as the boiler
controls require. Remove cover to get to terminal
screws. Because the entire power positioner moves
while in service, use Greenfield

TM

flexible conduit.
If the unit is likely to get wet, use liquid-tight
flexible conduit.

2

h.

Adjust limit switches so that they switch as the
piston reaches the fully extended and fully
retracted positions.

3

A

NOTE: LETTER DESIGNATIONS REFER TO NON-KIT

ITEMS MENTIONED IN INSTALLATION TEXT,
PARAGRAPH 5-5.

685012

LIMIT SWITCH KIT ITEMS

ITEM DESCRIPTION QTY

1 LIMIT SWITCH

2 SWITCH STRIKER

3 SWITCH BRACKET

4 P AN HEAD SCREW

5 FLAT WASHER

6 LOCKW ASHER

7 NUT PLA T

2

1

2

4

4

4

2

Figure 5-3. Limit Switch Installation

1. Observe limit switches while running power
positioner to both limits. Each switch should
switch on just as the piston reaches its
mechanical limit, and switch off as the piston
begins to go in the other direction.

2. To adjust switch, loosen screws (4,
Figure 5-3) until switch assembly will slide.
Slide switch assembly as necessary, then
retighten screws. Watch switch again while
running piston. Readjust as necessary.

IB-102-202N

5-7/5-8

SECTION VI. RECOMMENDED SPARE PARTS

The following tables give listings of replacement parts for standard and on/off 2-1/2 inch x 5 inch power positioners, and for
the standard pilot valve assembly.

Table 6-1. Recommended Spare Parts for the Standard Power Positioner.

FIGURE and
INDEX NUMBER PART NUMBER DESCRIPTION QTY

4-1, 12
4-1, 17
4-1, 22
5-1, 14 and 15

152507-001
4847B17H01
170857
173283

Seal
Cylinder Head Gasket
Piston Cup
Stem and Sleeve Assembly

1
2
2
1

(Matched Set)

(Not Shown)

3D39395G07

Maintenance Tool Kit

Table 6-2. Recommended Spare Parts for the On/Off Power Positioner

1

.

FIGURE and
INDEX NUMBER PART NUMBER DESCRIPTION QTY

4-1, 12
4-1, 17
4-1, 22
5-2
(Not Shown)

152507-001
4847B17H01
170857
ASCO #8340A2
3D39395G07

Seal
Cylinder Head Gasket
Piston Cup
Solenoid Valve Assembly
Maintenance Tool Kit

1
2
2
1
1

NOTE

Order replacement parts for the solenoid valve assembly directly from
ASCO at the following address:

ASCO Valves
Automatic Switch Co.
Florham Park, NJ 07932

Table 6-3. Recommended Spare Parts for the Standard Pilot Valve Assembly.

FIGURE and
INDEX NUMBER PART NUMBER DESCRIPTION QTY

5-1, 11
5-1, 8

171323
170960

Bottom Diaphragm
Top Diaphragm

IB-102-202N

6-1

1
1

NOTE

Table 6-4, Bill of Material for the 2-1/2 x 5 Power Positioner, includes part
numbers and descriptions that are keyed to figure and index number
references. The table covers all basic positioner parts. Refer to Tables 6-1, 6-2,
and 6-3 for recommended spare parts.

Table 6-4. Bill of Materials for the 2-1/2 x 5 Power Positioner

.

FIGURE and
INDEX NUMBER PART NUMBER DESCRIPTION QTY

4-1, 1

2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

27

5-1, 1

2
3

4

120079-010
170924
170925-002
120036-014
4847B25H01
4513C25H02
120090-250125

170952
171267
171266
163792-1932038
120114-017
170949
152507-001
120026-019
120114-029
4847B35G01
771B867H01
4847B17H01
3D39399H05
4847B29H01
170941
170942
170857
3D39399H02
120110-005
120171-002

4846B57G02
4847B34G01
3D39398

4847B19H01
4847B55H02
4844B16H01
173217-001
170964

Retaining Ring
Clevis Pin
Clevis
Hex Nut, 0.625-18
Piston Rod
Positioner Arm
Socket Head Cap Screw, 0.250-20 x 1.25 long
Calibration Spring (1 of 3 tensions)
0 - 30 lb Spring
3 - 15 lb Spring
3 - 27 lb Spring
Cap Screw
Lockwasher, #10
Seal Retainer
Seal
Hex Nut, 0.312-24
Lockwasher
Top Head Assembly
Elbow Fitting
Cylinder Head Gasket
Top Tubing, 18" long, 1/8" 304 S.S.
Cylinder
Garter Spring
Piston Cup Follower
Piston Cup
Bottom Tubing, 9" long, 1/8" 304 S.S.
Washer, 0.500 Plain
Elastic Stop Nut
Bottom Cylinder Head (1 of 2 Designs)
Bottom Cylinder Head, G05 Group

Bottom Cylinder Head, G06/G08 Groups

Pilot Valve Assembly
Socket Head Cap Screw
Rubber Boot
Top Spring Retainer, Standard

2
1
1
1
1
1
1
1

-

-

2
2
1
1
4
4
1
4
2
1
1
2
2
2
1
1
1
1

-

­1
2
1
1
1
1
1

Top Spring Retainer, EPT Option

Top Diaphragm Cover, EPT Option

Top Loading Spring

IB-102-202N

6-2

Table 6-4. Bill of Materials for the 2-1/2 x 5 Power Positioner (Continued).

FIGURE and
INDEX NUMBER PART NUMBER DESCRIPTION QTY

5-1, 5

6
7
8
9
10
11
12
13

14
15
16
17

18
4-1, 28
5-3, 1

2

3

4

5

6

7

5-2

4847B82H01
170960
4847B20H01
4847B22H01
171323
170959
4847B21
3D39396H02

173283

170955
170958
170968
174080-003
8741-001
3535B04G01
3535B01H01
70001DAJ4B
70500BD30C
70510CR10G
3535B09H01
3534B98
ASCO #8340A2

Top Diaphragm Seat
Top Diaphragm
Center Block
Center Diaphragm Post
Bottom Diaphragm
Bottom Diaphragm Seat

Top Stem Seat

Valve Body

O-rings

Stem and Sleeve Assembly

Sleeve

Stem

Bottom Stem Seat

Bottom Loading Spring

Sleeve Retainer

Tie-Rod, 0.312-24 x 9.38 long
Limit Switch
Switch Striker
Switch Bracket
Pan Head Screw, 0.138-32 x 1.25
Washer, #6 Flat
Lockwasher, #6 Split
Nut Plate, 0.138-32 Thread
Instructions, Limit Switch Kit
Solenoid Valve Assembly
(On/Off Units only)

1
1
1
1
1
1
1
1
4
1
1
1
1
1
1
4
2
1
2
4
4
4
2
1
1

IB-102-202N

6-3/6-4

SECTION VII. RETURNING EQUIPMENT TO THE FACTORY

7-1. RETURN PROCEDURE.

If factory repair of

defective equipment is required, proceed as follows.

a.

Secure a return authorization from a Rosemount
Analytical Sales Office or Representative before
returning the equipment. Equipment must be
returned with complete identification in
accordance with Rosemount instructions or it will
not be accepted.

In no event will Rosemount be responsible for
equipment returned without proper authorization
and identification.

b.

Carefully pack defective unit in a sturdy box with
sufficient shock absorbing material to insure that
no additional damage will occur during shipment.

c.

In a cover letter, describe completely:

1. The symptoms which indicate that the
equipment is faulty.

2. The environment in which the equipment has
been operating (housing, weather, vibration,
dust, etc.).

3. Site from which equipment was removed.

4. Whether warranty or nonwarranty service is
requested.

5. Complete shipping instructions for return of
equipment.

d.

Enclose a cover letter and purchase order, and ship
the defective equipment according to instructions
provided in Rosemount Return Authorization,
prepaid to:

American

Rosemount Analytical Inc.
R.M.R. Department
1201 N. Main Street
Orrville, Ohio 44667

European

Rosemount Ireland
Equipment Return Repair Dept.
Site 7 Shannon Industrial Estate
Co. Clare
Ireland

7-2. REPAIR TERMS

a.

If warranty service is requested, the defective unit
will be carefully tested and inspected at the
factory. If failure was due to conditions listed in
the standard Rosemount warranty, the defective
unit will be repaired or replaced at Rosemount's
option, and an operating unit will be returned to
the customer in accordance with shipping
instructions furnished in the cover letter.

b.

For equipment no longer under warranty, the
equipment will be repaired at the factory and
returned as directed by the purchase order and
shipping instructions.

.

IB-102-202N

7-1/7-2

INDEX

This index is an alphabetized listing of parts, terms, and
procedures having to do with the 2-1/2 Inch x 5 Inch Power
Positioner. Every item listed in the index refers to a location
in the manual by page number or numbers.

A

Active Coils, 3-3
Adjustement of Standard Units, 3-2
Air Filter, 3-1, 5-1, 5-2
Ambient Temperature, 3-1

C

Calibration Spring, 2-2
Clevis, 1-1, 3-1
Clevis Pin, 3-1
Control Signal, 2-1, 2-2, 3-2
Control System, 5-5
Cylinder, 1-1, 4-1, 5-4, 5-5

D

Damper, 1-1
Diaphragm, 2-2, 4-2, 5-4
Diaphragm Assembly, 2-2

E

Equation, 3-3, 3-4

L

Limit Switch, 1-2, 3-1, 3-4, 5-6, 5-7
Lower Limit, 3-2

M

Maintenance, 5-1, 5-2
Mounting Pivot, 3-1, 4-1
Mounting Pivot Pin, 3-1

O

On/Off Standard Option, 2-2

P

Piston, 1-1, 2-2
Piston Cups, 2-1, 4-2, 5-5
Piston Rod Seal, 4-2, 5-4
Pilot Valve, 1-1, 2-1, 4-1
Power Air, 1-1, 2-1, 4-1, 4-2

S

Shutoff Valve, 3-1
Sleeve, 4-1, 5-1
Sleeve and Stem, 2-2, 5-1
Solenoid Operated Valve, 2-3
Solenoid Valve, 1-2, 4-3, 5-2
Spare Parts, 6-1
Stem, 2-2, 4-1, 5-1

G

Guide Bearings, 2-2

I

Installation, 3-1

U

Upper Limit, 3-3

W

Wiring, 3-1

IB-102-202N

I-1/I-2

2/95

5/95-1849