Cameron BARTON 580A, BARTON 580A-0 User Manual

BARTON® NUCLEAR MODEL 580A

DIFFERENTIAL PRESSURE

SWITCH

User Manual

Part No. 9A-C10795, Rev. 03

September 2015

Model 580A-0 Switch
with Indicator

Contents

Safety ............................................................................................................ 2

Section 1—Introduction ................................................................................. 3

General ......................................................................................................... 3

Wiring ........................................................................................................ 5

Differential Pressure Unit (DPU) ............................................................... 5

Specications ............................................................................................... 6

General...................................................................................................... 6

Nuclear Qualications ............................................................................... 6

Application Specications ......................................................................... 7

Storage Specications .............................................................................. 7

Section 2—Installation ................................................................................... 9

Mounting/Piping/DPU Installation ................................................................. 9

Electrical Connection .................................................................................... 9

Switch Use .................................................................................................... 9

Startup ........................................................................................................ 10

Switch Wiring .............................................................................................. 10

Section 3—Maintenance and Calibration ....................................................11

Tools............................................................................................................ 12

Bezel/Lens Assembly or Cover Installation and Removal........................... 12

Pointer Installation and Removal ................................................................ 13

Pointer Installation .................................................................................. 13

Pointer Removal ...................................................................................... 14

Scale Plate Installation and Removal ......................................................... 14

Indicator Calibration .................................................................................... 15

Drive Arm Tightness Test ......................................................................... 17

Drive Arm Stop Adjustment ..................................................................... 17

Switch Calibration ..................................................................................... 18

Calibration Setup ..................................................................................... 18

Linkage Calibration Procedure ............................................................... 19

Safety

Before installing this product, become familiar with the installation instruc­tions presented in Section 3, Appendix A and all safety notes throughout.

!

 WARNING:Thissymbolidentiesinformationaboutpracticesorcircum-

stancesthatcanleadtopersonalinjuryordeath,propertydamage,or

economic loss.

CAUTION: Indicatesactionsorprocedureswhichifnotperformedcorrectly

mayleadtopersonalinjuryorincorrectfunctionoftheinstrument
orconnectedequipment.

IMPORTANT: Indicates actions or procedures which may affect instrument operation or

may lead to an instrument response that is not planned.

Changing Switch Set Point ......................................................................... 20

Denitions of Terms ................................................................................. 20

Best Practices for Set Points ................................................................... 20

Changing Set Point of an In-Service Instrument (Not Recommended for

Nuclear Qualied Units) .......................................................................... 21

Changing Set Point of an Out-of-Service Instrument .............................. 22

Range Changes ...................................................................................... 22

Troubleshooting ......................................................................................... 23

Section4—AssemblyDrawingandPartsList ........................................... 25

Section5—DimensionalDrawings ............................................................. 33

AppendixA—Model224DPU ....................................................................A-1

DPU Description ........................................................................................A-1

Specications .........................................................................................A-1

Theory of Operation ...............................................................................A-3

DPU Installation .........................................................................................A-4

General...................................................................................................A-4

Mounting.................................................................................................A-5

Piping .....................................................................................................A-5

Piping Diagrams .....................................................................................A-6

Startup ..................................................................................................A-12

DPU Maintenance ....................................................................................A-12

DPU Cleaning and Inspection ..............................................................A-13

Changing the DPU Range ....................................................................A-14

Replacing the Bellows Unit Assembly (BUA) .......................................A-14

DPU Troubleshooting ...............................................................................A-15

DPU Assembly Drawing and Parts List ....................................................A-17

DPU Dimensional Drawing ......................................................................A-19

3

Model 580A Differential Pressure Switch Section 1

Section 1—Introduction

General

The 580A Differential Pressure Switch actuates single or dual signal circuits

when predetermined limits of ow or level are exceeded. The DPU is con­nected to the process or vessel by tubing or piping. Changes in differential
pressure (DP) at the DPU produce a mechanical output which moves a pointer

and switch actuation controls.

For ow measurements, the instrument is connected to the high-pressure
and low-pressure sides of a primary device in the process run. Normally the
primary device will be an orice plate, venturi, or ow tube.

For liquid level measurement applications, the instrument is connected to
measure changes in differential pressure caused by variations in hydrostatic

pressures of the liquid in a tank.

The 580A switch is available in three model variations:

• Indicating Switch (Model 580A-0). This model, shown on the manual
cover, has a thick tempered plate glass lens and provides a visual indica­tion of the difference in the two monitored pressures.

• Blind Switch (Model 580A-2).This model has a solid metal cover and

provides no visual indication of differential pressure.

• Blind Switch with Internal Indicator. Unlike the indicating model with
the glass lens, there is no externally visible indicator. However, internally,
components are the same as in Model 580A-0. With the cover removed, a
user can use the internal indicator to determine DPU input pressure when

making adjustments to the switch setpoints.

The Model 580A uses two independently adjustable single-pole double-throw
(SPDT) snap-acting switches that are rated for high temperatures. Both sides

of the switches are wired, enabling the switches to serve both normally-open

and normally-closed applications. The direct-set switch contacts are adjustable

over a scale range of 10-90% nominal. Switches and all adjustments are read­ily accessible when the cover is removed (see Figures 1.1 and 1.2, page 4).

The 580A Switches (indicating and blind) are qualied per IEEE 323-1974,
IEEE 344-1975, IEEE 381-1977and NUREG 0588, Rev. 1 for either Func­tional and/or Pressure Boundary Integrity service in limited harsh environ-

ment applications.

The switch case is drawn stainless steel with a sealed glass header for the

electrical interface with the switches. No additional conduit seals are required

to ensure the integrity of the instrument.

4

Section 1 Model 580A Differential Pressure Switch

Left Switch

Right Switch

Pointer

Left Switch
Lock Screw

Plunger Screw

Actuating Cam

Left Switch
Adjustment
Assembly*

Switch Adjust Linkage

Plunger Screw

Right Switch
Lock Screw

Drive Arm

Stop Bracket

Movement Assembly

Terminal Strip

Switch Adjust Linkage

Right Switch
Adjustment
Assembly*

Range Adjust

* Switch Adjustment Assembly includes crank, index shaft, and index pointer.

Figure 1.1—580A (with indicator), internal components

Left Switch

Right Switch

Left Switch
Lock Screw

Plunger Screw

Actuating Cam

Left Switch
Adjustment
Assembly*

Switch Adjust Linkage

Plunger Screw

Right Switch
Lock Screw

Terminal Strip

Switch Adjust Linkage

Right Switch
Adjustment

Assembly*

Cam Actuator

* Switch Adjustment Assembly includes crank, index shaft, and index pointer.

Figure 1.2—580A (without indicator), internal components

The cam rotates counterclockwise with increased pressure. In Figure 1.3, page

5, the LOW switch (typically set to alarm at decreasing pressure) is set at 25%

differential pressure while the HIGH switch (typically set to alarm at increas­ing pressure) is set at 75% differential pressure.

5

Model 580A Differential Pressure Switch Section 1

1000

50

Zero DP

1000

50

Maximum DP

RED

Y ELLO W

BLUE

BLAC K

GREEN

WHITE

1000

50

SWI TCH "A"

(LEF T)

SWI TCH "B"

(RI GHT)

CAM

TERMI NAL
BLOCK I N

CASE

BOT H SW ITC HES RELAX ED

SWI TCH

P

LUNGER

SCREW

Mid-point DP

HIGHLOW

SWI TCH "A" AC TU AT ED/SW ITC H "B" RELAX ED

SWI TCH "A" RELAX ED/ SW IT CH "B" AC TU AT ED

SWITCH

CLOSED

CONTA CTS

OPEN

CONTA CTS

GREEN/W HITE GREEN/BLA CK

A (LEFT)

B (RIGHT)

YELLOW/BLUE YELLOW/RED

SWITCH

CLOSED

CONTA CTS

OPEN

CONTA CTS

GREEN/W HITE GREEN/BLA CK

A (LEFT)

B (RIGHT)

YELLOW/RED YELLOW/BLUE

SWITCH

CLOSED

CONTA CTS

OPEN

CONTA CTS

GREEN/W HITEGREEN/BLA CK

A (LEFT)

B (RIGHT)

YELLOW/BLUE YELLOW/RED

SWI TCH "A"

(LEF T)

SWI TCH "B"

(RI GHT)

SWI TCH "A"

(LEF T)

SWI TCH "B"

(RI GHT)

Notes:

1. CAM ROTATES COUNTER-CLOCKWISE WITH INCREASED DIFFERENTIAL PRESSURE

2. EACH SWITCH MAY BE SET AT ANY POINT FROM 10% TO 90% OF DP RANGE

3. WIRES: No. 22 AWG (Internal) and No. 18 AWG (External)

Figure 1.3—Switch wiring connections and actuation example

Wiring

Each switch is wired internally to a glass-sealed header using No. 22 AWG
ethylene tetrauoroethylene (Tefzel®) insulated wire for radiation service per
IEEE Standard 393-1974. Externally, from the header, permanently color
coded No. 18 AWG Tefzel® wires exit through a female conduit connection.

Differential Pressure Unit (DPU)

For detailed information on the Model 224 DPU, see Appendix A, page A-1.

6

Section 1 Model 580A Differential Pressure Switch

Specications

General

Actuating Unit (DPU) ...................... Model 224 DPU

Dial Size ......................................... 6 inches (150 mm)

Service Conditions (Normal)........... 40°F (4.4°C) to +180°F (+82.2°C) @ <90% R.H.

Switch Repeatability ....................... ±1% of calibrated span

Switch Set-point Range .................. 10 to 90% of calibrated span

Switch Deadband ........................... ±10% of calibrated span (maximum)

Switch Type .................................... Mechanical, Snap-Acting; both switches are SPDT

Activation ........................................ Increasing or decreasing scale

Switch Contact Rating:

5.0 Amps @ 125 VAC

5.0 Amps @ 250 VAC

3.0 Amps @ 30 VDC (resistive)

1.0 Amp @ 30 VDC (inductive w/arc suppression)

0.4 Amp @ 125 VDC (resistive)

0.2 Amp @ 125 VDC (inductive w/arc suppression)

Input Range .................................... 0-30" WC to 0-650 psid

Indicator Accuracy .......................... ±2.0% of calibrated span (for ranges to 400 psid)

1,2

Indicator Repeatability .................... ±0.5% of calibrated span

Safe Working Pressure ................... 500, 1000, 1500, 3000, or 6000 psig

Maximum Overrange ...................... To safe working pressure

Process Connections...................... 1/4" x 1/4", 1/4" x 1/2", 1/2" x 1/4" and 1/2" x 1/2"

(top x bottom)

Electrical Connections .................... Female, 3/4" NPT, 20 ft., color-coded Tefzel®

insulated 18 AWG wire (40 ft. leads available by
special order)

Torque Tube Rotation ..................... 8° (nominal)

1

± 2.5% of calibrated span for ranges between 400 and 600 psid; ±6% for ranges over

600 psid.

2

Additional 2% is applicable near the switch setpoints (±10% span).

Nuclear Qualications

The following nuclear qualication applications are based on Cameron Engi­neering Report 9A-CR3-580A-29 and 9A-CR3-580A31.

Design Basis Event (DBE) Performance Error1 (% of calibrated span):

Radiation (1 x 107 Rads) ................ ±10%

Seismic (12.5 Gs):

During Event ................................... ±10%

Following Event .............................. ±5%

Harsh Environment (≤ 200°F):

During Event ................................... ±10%

Following Event .............................. ±10%

1

Includes the cumulative effect of accelerated aging.

7

Model 580A Differential Pressure Switch Section 1

Application Specications

Model 580A switches were subjected to IEEE 323-1974/344-1975 quali­cation testing, which found the devices suitable for functional service in a
limited harsh environment. The service conditions associated with the limited
qualications are:

• 22 year qualied service life1 normal conditions of 104°F and 0 psig

• Radiation exposure to 1 x 107 Rads (TID)

• 85 days @maximum DBE conditions of 200°F, 10 psig ambient pressure

and ≥ 95% R.H.

• Seismic qualications:

– OBE @ 6.25 Gs (series of 5)
– SSE @ 12.5 Gs
– 5% critical damping
– No resonance in frequencies below 33 Hz

• Mechanical aging included:

– 25,000 pressure cycles during accelerated aging
– 12,500 electrical cycles during accelerated aging
– Vibration cycling using 0.2 G sinusoidal sweeps over the 1 to 200

Hz range at 1.0 octave/min.

1

Qualied Life: This equipment contains some organic material. The qualied life will be

governed by factors such as environmental temperature, radiation exposure, and activa­tion energy.

Storage Specications

Storage per ANSI N45.2.2-1978 Level B at 70°F (21°C) ±20°F (±11°C) in
factory sealed package for 2.5 years maximum will not affect installed service

life.

8

Section 1 Model 580A Differential Pressure Switch

9

Model 580A Differential Pressure Switch Section 2

Section 2—Installation

The instrument should be inspected at time of unpacking to detect any dam-

age that may have occurred during shipment.

IMPORTANT: The DPU was checked for accuracy at the factory. Do not change any of

the settings during examination or accuracy could be affected.

For applications requiring special cleaning/precautions, a polyethylene bag
is used to protect the instrument from contamination. This bag should be

removed only under conditions of extreme cleanliness.

Mounting/Piping/DPUInstallation

Mount the instrument with four customer-supplied 5/16-in. (8-mm) bolts,
Grade 5 or greater, torqued to 17 ft/lbs. Mounting structures should be
designed to avoid resonance and/or minimize resulting amplication below
33 Hz. Response spectra at mounting surface of the instrument shall not
exceed those in the R3-580A-29 Qualication Report. Interfacing process

tubing and conduit shall be supported by the same mounting as the DP instru-

ment base in order to minimize relative motion of the DP instrument and

connections.

Dimensional drawings are provided on Section 5—Dimensional Drawings,

page 33.

See Appendix A, page A-1, for Model 224 DPU installation and mainte-
nance information.

Electrical Connection

Units are supplied with dual alarm switches. The direct-set switch contacts
are adjustable over 10% to 90% of the scale range.

The high switch and low switch set point adjustment procedures are covered

in Changing Switch Set Point, page 20.

For physical location of switches, see Figures 1.1 and 1.2, page 4.

SwitchUse

Switch contact life is inuenced by various application conditions such as
temperature, humidity, airborne contamination, vibration, amount of plunger
travel, cycling rate, and rate of plunger travel (and others), as well as by the

electrical (circuit) characteristics.

10

Section 2 Model 580A Differential Pressure Switch

IMPORTANT: Arc suppression for inductive loads will prolong the life of the switch

contacts.

Startup

For startup procedures, warnings, and other information on the Model 224

DPU, see Appendix A, page A-1.

IMPORTANT: To ensure the unit calibration is within factory-set calibration tolerances,

perform the Calibration Check procedure on page 12.

SwitchWiring

IMPORTANT: Figure 2.1 shows switch contacts in the relaxed (shelf) condition, the low

switch set to trip at a position below the pointer scale position, and the
high switch set to trip at a position above the pointer scale position. NO
= Normally Open in (shelf) condition. NC = Normally Closed in (shelf)
condition. C= Common.

LOW & HIGH SPDT SWITCHES

NO NOC CNC NC

RED

YELLOW

BLUE

RED

YELLOW

BLUE

WHITE

GREEN

BLACK

WHITE

GREEN

BLACK

1 2 3 4 5 6 7 8 9 10

Figure 2.1—Low/high SPDT switch diagrams

Table2.1—SwitchWireColorCoding

580ACurrentCongurations

NO C NC

Low Red Yellow Blue

High Black Green White

11

Model 580A Differential Pressure Switch Section 3

Section 3—Maintenance and Calibration

The following checks are recommended for preventive maintenance:

• Periodically inspect the alarm switch mechanism to verify that all mount­ing screws are seated properly.

• Inspect linkage for wear.

• Inspect integrity of electrical circuits. Tighten as necessary.

When repairs are necesssary, review this section for maintenance procedures
such as bezel/lens installation and removal, pointer installation and removal,
indicator calibration, switch calibration, and switch set point changes. Refer
to Figure 3.1 as needed for component identication.

SWITCH LOCKS

ZERO ADJUST

POINTER STOP

3/4 NPT (INTERNAL)
CONDUIT CONNECTOR
20 FT (6.1 M) LG
18 AWG EXT LEADS STANDARD;

40 FT (12.2 M) LG LEADS OPTIONAL

SWITCH ADJUST 1/8 (3.2)
HEX 1/8 DP

TO ADJUST SWITCH SETTING

REMOVE SCREWS AND COVER

RANGE ADJUST

POINTER

Figure 3.1—Model 580A adjustment controls

IMPORTANT: Never perform maintenance/repair on the Model 580A differential pres-

sure switch without rst reviewing all procedures and warning/caution

notices in this manual. See Appendix A, page A-1, for related warning/
caution notices and instructions for the Model 224 DPU.

12

Section 3 Model 580A Differential Pressure Switch

Tools

The following tools are recommended for general maintenance of the Model
580A differential pressure switch.

Table 3.1—Tools

Equipment Purpose

Pointer Puller Pointer removal

Small Screwdriver Calibration adjustment

Medium Screwdriver Bezel removal and replacement

1/4" and 1/8" Open-end Wrenches Zero (1/4") and Range (1/8") adjustments

1/8 Hex Allen Wrench Switch set point adjustment

Bezel/LensAssemblyorCoverInstallationandRemoval

To remove the bezel/lens assembly or cover, loosen the eight screws on the
front and lift the assembly or cover from the enclosure.

To reinstall the bezel/lens assembly (580A-0 only), install the O-ring in the
groove of the case, assemble the bezel, lens, and lens gasket, and realign the
screw holes with the holes in the case. Then, reinstall the screws in the bezel

to secure all components to the case. Torque the screws per Table 4.3, page

31.

To reinstall the cover (580A-2), install the O-ring in the groove of the case
and realign the screw holes in the cover with the holes in the case. Reinstall
the screws in the cover to secure it to the case. Torque the screws per Table

4.3, page 31.

Calibration Check

To ensure the unit calibration is within factory-set calibration tolerances,
perform the following procedure.

IMPORTANT: Review all Model 224 DPU procedures and WARNINGS/NOTICES in

Appendix A, page A-1, before performing this procedure.

1. Mount the instrument in an approximately level position and connect to a

standard pressure source.

2. If the zero indication is incorrect, adjust it as follows:
a. Remove the bezel/lens assembly or cover.
b. Using a 1/4" open-end wrench (included in calibration toolkit, Part

No. 9A-0288-1032B), hold the hexagon pointer hub xed and rotate
the pointer with ngers until the pointer indicates zero on the scale.

See Figure 3.2, page 13.

13

Model 580A Differential Pressure Switch Section 3

c. Replace the bezel/lens assembly.

HUB

Pointer "slipped"
rotated on hub

Hub held in place
with 1/4" wrench

Figure 3.2—"Slipping" pointer

3. To test for reverse travel, connect the pressure source to the low-pressure
(LP) housing and vent the HP housing. Apply pressure to approximately
150% of the DP range. The pointer should move approximately 5% to
10% below zero.

4. To test for overtravel, connect the pressure source to the HP housing and
vent the LP housing. Apply pressure to approximately 150% of DP range.
The pointer should move approximately 5% to 10% above the full scale

mark.

5. Apply 0, 50, and 100% of full scale pressure. If the indication is within

specied limits, no adjustments are necessary. If the indication is not
within specied limits, perform a complete calibration (see Indicator

Calibration, page 15).

6. Make sure the instrument zero indication is correct; otherwise, repeat

step 2.

7. Verify the switch set points (refer to Changing Switch Set Point, page

20).

PointerInstallationandRemoval

During adjustment and calibration of the unit, it may be necessary to remove
and reinstall the pointer. See the following procedures for instructions. Note
that the scale plate is split to allow it to be removed without pulling the

pointer.

Pointer Installation

1. Position the pointer on the movement shaft with the pointer set at zero
scale. Obtain 75% to 90% pointer hub engagement on the movement

pinion shaft. The pinion shaft must not extend through the pointer hub. It
may be necessary to enlarge the hub hole using a tapered broach (includ-

ed in the calibration toolkit, Part No. 9A-0288-1032B).

14

Section 3 Model 580A Differential Pressure Switch

2. Lightly tap the pointer hub with a hand-set or other at-end tool. Use
perpendicular blows to avoid bending the shaft.

3. Check the calibration of the indicating switch over its entire range (refer
to Indicator Calibration, page 15). If the indicating switch is correctly

calibrated, secure the pointer to the movement shaft by tapping the hub
with a hand-set or other at-end tool.

4. Test the pointer for tightness by moving the pointer from the zero to the
50% position manually, and then letting the pointer return freely to zero.

If the pointer indicates a shift, tap the pointer hub to tighten it to the
shaft.

Pointer Removal

The pointer is removed with a pointer puller shown in Figure 3.3. This tool is
included in the calibration toolkit, Part No. 9A-0288-1032B.

To remove the pointer, perform the following steps:

1. Slide the pointer puller along the pointer until the pin protruding from the
tip of the screw in the pointer puller is directly over the movement shaft

and the arms of the pointer puller are directly under the pointer.

2. Gently turn the knurled head of the screw clockwise, pushing the pin

against the movement shaft and lifting the pointer with the arms. Finger
pressure should be sufcient to pull the pointer free. If more pressure is

required, an Allen wrench (inserted into head of the screw) can be used.

However, care should be exercised to avoid breaking the pin.

HUB

MOVEMENT SHAFT

POINTER

HUB

POINTER PULLER

Figure 3.3—Pointer puller (Part No. 9A-0163-0005B)

ScalePlateInstallationandRemoval

During adjustments and calibration of the unit, it may be necessary to remove
and reinstall the scale plate. The scale plate is split to allow removal without
pulling the pointer. It is held in place by ve screws (Item 40 in Figure A.1,

page A-2) and two mounting tabs at 12 o'clock and 6 o'clock positions. The

scale plate halves rest against the top tab (12 o'clock), and slide beneath the
bottom tab (6 o'clock).

15

Model 580A Differential Pressure Switch Section 3

To remove the scale plate, move the pointer to the 12 o'clock position, remove
the screws from the scale plate, and gently guide the scale plate halves from
beneath the bottom mounting tab. Screws are located at 12, 3 and 9 o'clock
positions and near the center of the plate which overlays a narrow bracket.

To reinstall the scale plate, repeat the installation steps in reverse order, as
follows. Holding the pointer in the 12 o'clock position, place the scale plate
halves against the top mounting tab and guide the bottom edges behind the
bottom tab. Replace the screws in the top tab and in the center of the scale
plate. No screw is used with the bottom tab.

Indicator Calibration

If the DPU assembly is replaced on a Model 580A differential pressure switch

with indicator, the indicator must be recalibrated. This procedure does not ap­ply to the 580A-2 blind switch without indicator.

IMPORTANT: Review all Model 224 DPU procedures and WARNINGS/NOTICES in

Appendix A, page A-1, before performing this procedure.

1. Securely mount the instrument in an approximately level position and
connect the DPU, as described in Mounting, page A-5.

2. Remove the bezel/lens assembly or cover.

3. Align the linkage between the drive arm and the movement at 50% differ­ential pressure (DP) as shown in Figure 3.3. Inspect parts for straightness

and pivot-t without binding.

Figure 3.4—Range/linearity adjustment (50% DP)

4. Check the pointer for zero indication. If necessary, set the pointer to zero
by slipping the pointer on the hub, per step 2 of Calibration Check, page

12.

5. Apply 100% pressure. If the pointer exceeds full-scale, adjust the range
adjust screw with a 1/8-in. open-end wrench to lengthen the movement

range arm..

16

Section 3 Model 580A Differential Pressure Switch

6. Release pressure. Set the pointer to zero, by slipping the pointer on the

hub, per step 2 of Calibration Check, page 12.

7. Repeat steps 4 and 5, as necessary, to obtain the correct zero/full-scale.

8. Apply 50% DP. If the pointer indicates 50%, proceed to step 9. If the
pointer does not indicate 50% scale, adjust linearity as follows.
a. Loosen the drive arm screw (Figure 3.5) and move the arm to shift

the pointer in the direction of the error a distance of about 10 times

the linearity error.

b. To prevent interference, check to see that the drive arm clears the

end of torque-tube housing by approximately 0.030 in. before re-

tightening the drive arm screw.

c. While supporting the block/shaft, tighten the clamp screw until it is

snug to the shaft.

d. Still supporting the block/shaft, tighten the clamp screw an addition-

al 1/3 to 1/2 turn. (This screw can normally turn one full revolution

before breaking.)

e. Perform the Drive Arm Tightness Test described on page 17 before

returning the instrument to service.

1/8” WRENCH

(PN 9A-0163-0044C)

CLAMP SCREW

DRIVE ARM

LINK

SINTERED

CLAMP BLOCK

TO TIGHTEN

.03 (approx)

M224

SHAFT

Figure 3.5—Drive arm to torque tube connection

9. Release pressure and reset the pointer to zero. Check the span. If the gear
in the movement reaches a limit of travel as a result of linearity adjust-

ment (step 8), slip the range arm along the gear approximately 5 degrees

from the normal 37.5 degree angle to approximately 43 degrees (see

step 3). To slip the range arm, apply pressure to the range arm with the

thumb, while holding the gear rmly in place. Retest the pointer response
at 50%, 0%, and 100% of full-scale differential pressure, and adjust the

linkage until the readings are acceptable.

17

Model 580A Differential Pressure Switch Section 3

10. Apply 0%, 25%, 50%, 75%, 100%, 75%, 50%, 25%, and 0% of full-scale
differential pressure consecutively to the instrument without overshoot.
Lightly tap the indicator to overcome friction. The pointer should accu-

rately indicate each applied pressure.

11. Test the instrument repeatability by applying 0%, 50%, 0%, 50% of full-

scale differential pressure. The indicator should accurately indicate each
applied pressure.

12. Set the drive arm stop to prevent the pointer from striking the post lock

on the scale.

13. Test the pointer for tightness per the pointer installation instructions on

Pointer Installation, page 13.

14. If the drive arm screw has been loosened, check for tightness by perform­ing the Drive Arm Tightness Test described below.

15. Reassemble the unit per the cover installation instructions on Bezel/Lens

(or Cover) Installation and Removal, page 12.

Drive Arm Tightness Test

This procedure tests the tightness of the drive arm's connection to the torque
tube by applying torque developed by the DPU onto a xed drive arm. Ap-

ply pressure slowly, as torque is being applied to the connection through the

torque tube drive shaft.

1. With the pointer at normal 0% torque tube rotation position (0% on a
normal 0 to 100% scale unit), adjust the drive arm stop bracket (or use
alternate means) to prevent the pointer from moving (the stop bracket
interferes with drive arm movement).

IMPORTANT: On reverse acting/split range units, it will be necessary to pressurize the

DPU to move the pointer to the minimum scale position. On suppressed
units, it will be necessary to apply pressure to establish a reference point
to check for "zero" shift.

2. Pressurize the DPU to full scale DP (100% of full scale range) to apply 8
degrees of equivalent torque to the connection.

3. Observe the shift in the "zero" indication following DPU depressuriza­tion (as required) and drive arm stop bracket readjusting (to allow free
movement of drive arm and pointer). A downscale (counter-clockwise)
shift in "zero" of greater than 1/2% indicates drive arm slippage, neces-

sitating further clamp block tightening.

Drive Arm Stop Adjustment

1. Apply sufcient pressure to the high-pressure housing to deect the

pointer against the full range post lock on the scale plate.

2. Slide the upper drive arm stop bracket against the drive arm and tighten

the drive arm stop bracket screw.

18

Section 3 Model 580A Differential Pressure Switch

3. Apply sufcient pressure to the low pressure housing to deect the
pointer against the zero stop post lock on the scale plate.

4. Bend the zero drive arm stop against the drive arm.

5. Verify calibration as applicable.

SwitchCalibration

Before performing a complete calibration of the switch, perform a calibration
check (See Calibration Check, page 12). If the instrument is out of calibra-

tion, remove the bezel/lens and scale plate and inspect the switch mechanism

(Figure 3.6) to verify the following:

• The roller rotates without wobble or binding.

• The cam does not touch the roller side shields.

• The actuator arm moves freely on its pivot.

• All switch mounting screws are tight.

• Linkages are straight and do not bind at the pivots.

Correct any problems that are observed. If no problems are observed, proceed

with a complete calibration.

SWITCH

ACTUATOR ARM

STOP
SCREW

PLUNGER

SCREW

CAM ROLLER

CAM

Figure 3.6—Switch mechanism

Calibration Setup

1. Connect an output device (lamp or buzzer) to the switch output leads.

2. Connect a test voltage to the switch input terminals on the terminal strip.
(A low voltage is recommended for safety.)

3. Unlock the switch plate and move the plate until the roller is positioned
at the top of the cam.

4. Advance the plunger screw until the switch actuates, then advance the

plunger screw an additional 60° (one at).

5. Exercise the switch roller across the top of the cam to verify steady
operation. Advance the stop screw to touch the switch, then back out the
screw 1.5 turns (9 ats).

19

Model 580A Differential Pressure Switch Section 3

Linkage Calibration Procedure

The switch linkage should be calibrated whenever the Model 580A switch has

been rebuilt.

To calibrate the switch linkage, perform the following steps. Refer to Figure

3.7 as needed.

1. Loosen the three linkage screws and turn the crank to the 12 o’clock

position.

2. Use a 1/8-inch Allen wrench to hold the index shaft and slip the index
pointer to 0 on the switch index. Tighten the screw on the crank to the
mid-slot position to set the crank radius.

3. Turn the index pointer to index number "1" on the outer edge of the
switch index.

4. Apply 10% differential pressure and adjust the switch plate until the
switch actuates. Lock the two linkage screws.

5. Rotate the index pointer to index number “9.” Apply 90% differential
pressure and adjust the crank radius until the switch actuates.

6. Recheck 10% and 90% set points. Adjust the crank radius and the index
pointer until both set points are accurate within a 2% tolerance (nominal).

Figure 3.7—Linkage arrangement

7. If the switch is to be eld-set at low differential pressure values (1% or
2% of pressure range), check the crank to prevent a 12 o'clock position.

Otherwise, the minimum set point position will be restricted and the set

point may become reversed.

8. Adjust the low switch to actuate at the desired pressure by applying test
pressures in a decreasing direction, in discrete steps. Allow the unit and

20

Section 3 Model 580A Differential Pressure Switch

the pressure system to stabilize. Then change the pressure by a small

amount. The magnitude of the pressure change is determined by the
desired accuracy of the test. Tighten the lock screw before testing the
switch performance.

IMPORTANT: The high switch is usually set to actuate at increasing pressure. When

calibrating the high switch, apply test pressure in an increasing direction.
This amount of loading will prevent cam-runout of a similar condition.

IMPORTANT: Excessive plunger loading (more than 3 ats) may cause the roller to

drag on the cam. Cam friction will be apparent by excessive hysteresis,
erratic pointer readings, and inconsistent switch response.

9. Check the switch deadband, (actuate to reset) by applying differential
pressure, rst in a decreasing direction, then in an increasing direction
(opposite for high switch direction). Observe pressures. To reduce the
deadband, advance the plunger screw by no more than two ats.

10. Adjust the high switch to actuate at the desired pressure. The procedure is

the same as for the low switch.

ChangingSwitchSetPoint

(Tools: Screwdriver, 1/8-in. hex Allen wrench)

Denitions of Terms

Set Point. The measured pressure at which the snap-switch actuates and

thereby changes the states of the N.O. and N.C. contacts. For example, the set

point of the low switch is 24 psid with decreasing pressure.

Deadband. The difference in measured pressures between switch-actuation
and switch-reset. Deadband is usually expressed as percentage of full scale

(% of F.S.). Deadband is not adjustable. For example, the switch in the
example above was found to reset at 26.4 psid with increasing pressure. The
deadband was 2.4 psi, or 4% of the full scale for a unit calibrated 0 to 60 psid.

Best Practices for Set Points

1. Always check the set point after tightening switch lock screws.

2. Switch setpoints may be set at any point of the scale range, except in a

location that will prevent the deadband from enabling the switch to reset

itself. For example, the high switch (right side of scale) may be set at

full scale, but should not be set near zero. The low switch may be set at
zero, but should not be set near full scale. (Observe deadband values for
specic models).

3. If switch performance is unsatisfactory (set point does not repeat, dead-

band is excessive, pointer exhibits hysteresis, contacts are unstable, etc.),

21

Model 580A Differential Pressure Switch Section 3

remove the scale plate and inspect the switch and the switch mechanism.
The scale plate is split to allow for removal without pulling the pointer.

Changing Set Point of an In-Service Instrument (Not Recommended for
Nuclear Qualied Units)

Use the following procedure to set a set point for an instrument that is in ser­vice, when calibration pressures cannot be applied. See Figure 3.8 for specic
locations denoted by items A, B, C and D.

1. Remove the bezel/lens assembly or cover. Do not remove the pointer or

scale plate.

2. Insert hex wrench in the switch adjust post.

3. Loosen the switch lock-screw (item B) 1/2 to 1 turn.

4. With the hex wrench, move the index pointer (item C) to the new set
point as indicated on the switch index (item D).

5. If possible, check the set point by varying the process pressures and ob-

serving the pointer readings when the switch actuates. (Open the mani­fold bypass valve slowly and watch for “pointer-jump” at the set point or

by electrical signal.) Adjust the setting, if necessary, and repeat the test

several times to verify stability.

Figure 3.8—Set point adjustment

IMPORTANT: The switch index has 10 divisions, marked 0, 5, and 10. These match the

markings on the outer edge of the scale.

22

Section 3 Model 580A Differential Pressure Switch

Example: Scale has range of 0-60 psid. Set point is 24 psid, with decreasing
pressure, (24/60 x 10 = 4).

1. Move the index pointer (item C) for the low switch from division 0 to
division 4 tick mark.

2. Tighten the switch lock (Item B) to a snug position, then turn an ad-

ditional 1/4 turn to place the set point within ±2% of full scale. Do not
overtighten.

Repeat steps 1 and 2 for the high switch, moving the index pointer from divi­sion 10 to division 4.

Changing Set Point of an Out-of-Service Instrument

Use the following procedure to set a set point for an instrument that is out of
service—typically, an instrument that is disconnected from process lines or

mounted on a bench.

1. Drain and vent the housings.

2. Attach the calibration pressure source (air or N2) to the DPU HP housing.

3. Apply varying pressures in discrete steps and observe pointer readings

for accuracy. Use a pressure standard (Heise gage or equivalent) for
reference. A “bleed-pressure” method may cause errors.

4. Change the switch set point as described in Changing Set Point of an In-

Service Instruments, page 21.

5. Check the set point by changing measured pressure to actuate the switch.
For example: To verify a low-switch set point of 24 psid, apply approxi­mately 30 psi. Reduce pressure to approximately 25 psid, hold for a few
seconds, then continue in 1/4 psid steps until the switch actuates. If the

set point is incorrect, continue instructions in Changing Set Point of an

In-Service Instruments, page 21.

6. To measure the switch deadband, reduce the pressure to zero, then in-

crease pressure until the switch resets.

7. To verify repeatability of a set point, repeat step 5 several times. For
improved accuracy, use smaller increments of pressure. Allow extra time
for gages with a slow response and for test systems that have long runs of

small-bore tubing.

High-alarm switches (right side of the scale) are adjusted in a similar manner.

Apply increasing pressure to establish the switch set point, and apply decreas­ing pressure to measure the deadband.

Range Changes

Changing the range of a Model 580A differential pressure switch typically
requires replacement of the DPU. Contact factory for assistance.

23

Model 580A Differential Pressure Switch Section 3

Troubleshooting

For switch troubleshooting tips, see Table 3.2 below. For information related

to the Model 224 DPU, see Table A.3, page A-15.

Table3.2—Troubleshooting

Problem Possible

Source

Probable Cause Corrective

Action

Low or No

Indication

Indicator,
Alarm Switch
Mechanism

Loose linkage or movement Tighten or replace

Out of calibration Calibrate

Pointer loose Tighten pointer

Dirty or corroded mechanism Clean or replace

Wiring interfering with movement Re-route wiring

Dirty mechanism Clean mechanism

High
Indication

Indicator,
AlarmSwitch
Mechanism

Loose linkage or movement Tighten or replace

Out of calibration Calibrate

Erratic
Indication

Indicator,
Alarm Switch
Mechanism

Linkage dragging or dirty Adjust or clean

Pointer dragging on scale plate Adjust pointer

position

Inaccurate
or No

Electrical
Alarm

Power
Supply

Blown fuse Replace fuse

Broken or loose wire Repair

Alarm Switch Switch not properly adjusted Adjust switch

Dirty or burned contacts Replace switch

24

Section 3 Model 580A Differential Pressure Switch

Table3.2—Troubleshooting

Problem Possible

Source

Probable Cause Corrective

Action

Switch
Drifts
(set point
not repeat­able)

Process
Changes

Transients or surges cause switches to actu­ate prematurely

Add time delay
gages or add time
circuit

Set point and/or deadband are too wide in
pressure values

Specify DP range as
low as practical; set
point repeatability
and deadband are
percentage of full
range

Electrical overloads affect the spring proper­ties of the leaf actuator in the switch

Examine circuits for
voltage, amperes

DC inductive loads cause arcing and burning
of contacts

Consider arc­suppression devices
or relays

Accumulation of uids in piping generate
articial signal

Vent gas or drain
liquids from signal
lines

Calibration
Techniques

Failure to check set point after locking Verify set point

repeatability after
locking switch plate

Rapid pressure change or venting system During calibration,

make pressure
changes in slow,
discrete steps

Pressure application in reverse Test low-alarm with

decreasing pressure
and high-alarm with
increasing pressure

Reference gage inaccuracy Suitable pressure

standard such as
manometer, dead­weight tester, or
Heise-type gage
may be required

Damage to switch contacts Adjust plunger

screws carefully
to avoid damage
to internal parts of
switch

25

Model 580A Differential Pressure Switch Section 4

Section4—AssemblyDrawingandPartsList

LOCATE THE SCALE PLATE
UNDER THE MOUNTING TAB
WITHOUT A SCREW AT THE
6 O’CLOCK POSITION.

Figure 4.1—Model 580A-0 indicating switch (shown with glass lens)

26

Section 4 Model 580A Differential Pressure Switch

Table 4.1 contains components for Model 580A-0 indicating switches and

Model 580A-2 blind switches with internal indicator.

For parts list information on Model 580A-2 blind switches without indicator,
see Table 4.2, page 29.

Table4.1—PartsList,Model580A-0IndicatingSwitchand

Model580A-2BlindSwitchwithInternalIndicator

Item Description Part No.

Per

Unit

1 Low Switch Assembly (Temperature Stabilized) 9A-C0580-3008B 1
2 High Switch Assembly (Temperature Stabilized) 9A-C0580-3009B 1
3 Low Drive Plate Assembly 9A-C0288-0026B 1
4 High Drive Plate Assembly 9A-C0288-0027B 1
5 Low Switch Adjustment Index Assembly 9A-C0288-0028B 1
6 High Switch Adjustment Index Assembly 9A-C0288-0029B 1
7 Pointer Assembly (select one) 1

White 9A-C0580-1060B

Black 9A-C0580-1061B
8 Washer, Spring 9A-C0257-0019C 2
9 Lock Screw 9A-C0580-1017C 2
10 Screw, B.H. Slotted, 3-48 x 3/16 Lg. 9A-C0117-0007J 6
11 Washer, Flat, No. 3 9A-C0003-0045K 11
12 Screw, B.H. Slotted, 8-32 x 3/16 Lg. 9A-C0117-1001J 2
13 Retaining Ring 9A-C0087-0015T 2
14 Grip Ring, Retaining (Included in Items 1 and 2) 9A-C0087-1055T 2
15 Link Plate 9A-C0288-0016C 2
16 Set Screw, 6-32 x 1/4 Lg. 9A-C0320-1010J 1
17 Strap 9A-C0288-0017C 2
18 Washer, Flat 9A-C0317-0019C 2
19

Set Screw, Hex Socket, 6-32 x 3/8 Lg. 9A-C0320-1015J

2

20 Movement Assembly 9A-C0580-1108B 1
21 Link Assembly 9A-C0288-0036B 1
22 Drive Arm Assembly 9A-C0288-0048B 1
23 Nut, Hex, 4-40 9A-C0500-1026J 1
24 Block, Terminal (TB1) 9A-CS054-0011Z 1
25 Post, Lock 9A-C0277-0020C 1
26 Riser, Movement 9A-C0277-0035C 2
27 Bracket, Stop 9A-C0288-0028C 1
28 Bracket, Terminal Block 9A-C0288-0029C 1
29 DPU Assembly, Model 224 Select —
32 Case & Connecter Assembly 9A-C0580-1123B 1
33 Lens/Cover: Glass Lens (select one) 1

Model 580A-0 (with glass lens) 9A-C0580-1120C

Model 580A-2 (blind with indicator) 9A-C0580-1119C

27

Model 580A Differential Pressure Switch Section 4

Table4.1—PartsList,Model580A-0IndicatingSwitchand

Model580A-2BlindSwitchwithInternalIndicator

Item Description Part No.

Per

Unit

34

Bezel (Model 580A-0 only) 9A-C0580-1125C

1

35 Lens Gasket (Model 580A-0 only) 9A-C0580-1126C 1
36 Bracket (Switch to DPU) 9A-C0580-1059C 1
37 Header Assembly 9A-C0580-1018B 1
38 Screw, Cap:10-32 (select one) 8

Model 580A-0 (with glass lens), 1" long 9A-C0220-1062J

Model 580A-2 (blind with indicator), 1/2" long 9A-C0220-1031J
39 Screw, Rd. Hd., Slotted, 6-32 x 3/8 Lg. 9A-C0111-0015J 2
40 Screw, Pan. Hd., Slotted, 4-40 x 1/8 Lg.

(Model 580A-0 only)

9A-C0119-1116J 5

41 Screw, B.H., Slotted, 4-40 x 3/16 Lg.

(Model 580A-0 only)

9A-C0117-0012J 1

42 Screw, B.H., Slotted, 6-32 x 3/16 Lg.

(Model 580A-0 only)

9A-C0117-0013J 2

43 Bracket, Mounting 9A-C0273-0001C 2
44 Screw, Hex Head, 1/4-28 x 1/2 Lg. 9A-C0116-1011J 4
45 Washer, Ext. Tooth, 1/4 9A-C0003-0068K 4
46 Plug 9A-C0224-0269C 1
47 O-ring (Torque Tube), EPT 9A-C0001-1068R 1
48 Ring, Grip 9A-C0087-1029T 1
49 Washer, Split Lock, 3/8 9A-C0003-0093K 2
50

O-ring (Header), EPT 9A-C0001-1066R

1

51 Nut, Hex., 3/8-16 9A-C0500-0039J 2
52 O-ring (Lens/Cover), EPT 9A-C0001-1057R 1
53 O-ring (Plug), EPT 9A-C0001-1051R 1
54 Set Screw, Socket Hex, 10-32 x 3/8 Lg. 9A-C0320-0024J 2
55 Screw, Rd. Hd., Slotted, 6-32 x 3/16 Lg. 9A-C0117-0013J 2
56 Scaleplate (select one) 1

White 9A-C0580-1109C

Black 9A-C0580-1110C
57 Screw, Flat Hd., 10-32 x 1/2 Lg. 9A-C0240-0015J 6
58 Washer, Split Lock, #8 9A-C0003-0036K 2
60 Washer, Split Lock, #6 9A-C0003-0038K 2
72 Case Bushing 9A-C0580-1101C 1
* Silicone Grease 9A-C0002-1003U A/R
** Thread Lubricant, Molykote 9A-C0002-0010U A/R
*** Locktite 222 9A-C0007-1033U A/R

Notes:
*Prior to installation, lubricate O-rings (Items 47, 50, 52 and 53) with silicone grease.
**Apply thread lubricant to threads of Item 16 (set screw) and Item 38 (cap screw) before installing.
***Apply Locktite 222 to Items 19 and 54 (set screw) when installing in the mounting plate.

28

Section 4 Model 580A Differential Pressure Switch

Figure 4.2—Model 580A-2 blind switch without indicator

29

Model 580A Differential Pressure Switch Section 4

Table 4.2 contains components for Model 580A-2 blind switches without
indicator.

For parts list information on Model 580A-0 indicating switches and Model
580A-2 blind switches with internal indicator, see Table 4.1, page 26.

Table4.2—PartsList,Model580A-2BlindSwitchwithoutIndicator

Item Description Part No.

Per

Unit

1 Low Switch Assembly (Temperature Stabilized) 9A-C0580-3008B 1
2 High Switch Assembly (Temperature Stabilized) 9A-C0580-3009B 1
3 Low Drive Plate Assembly 9A-C0288-0026B 1
4 High Drive Plate Assembly 9A-C0288-0027B 1
5 Low Switch Adjustment Index Assembly 9A-C0288-0028B 1
6 High Switch Adjustment Index Assembly 9A-C0288-0029B 1
8 Washer, Spring 9A-C0257-0019C 2
9 Lock Screw 9A-C0580-1017C 2
10 Screw, B.H. Slotted, 3-48 x 3/16 Lg. 9A-C0117-0007J 6
11 Washer, Flat, No. 3 9A-C0003-0045K 10
12 Screw, B.H. Slotted, 8-32 x 3/16 Lg. 9A-C0117-1001J 2
13 Retaining Ring 9A-C0087-0015T 2
14 Grip Ring, Retaining (Included in Items 1 and 2) 9A-C0087-1055T 2
15 Link Plate 9A-C0288-0016C 2
16 Set Screw, 6-32 x 1/4 Lg. 9A-C0320-1010J 1
17 Strap 9A-C0288-0017C 2
18 Washer, Flat 9A-C0317-0019C 2
19

Set Screw, Hex Socket, 6-32 x 3/8 Lg. 9A-C0320-1015J

2

22 Drive Arm Assembly 9A-C0580-1076B 1
24 Block, Terminal (TB1) 9A-CS054-0011Z 1
28 Bracket, Terminal Block 9A-C0288-0029C 1
29 DPU Assembly, Model 224 Select —
32 Case & Connecter Assembly 9A-C0580-1123B 1
33 Lens/Cover: Blind Cover 9A-C0580-1119C 1
36 Bracket (Switch to DPU) 9A-C0580-1059C 1
37 Header Assembly 9A-C0580-1018B 1
38 Screw, Cap: 10-32 x 1/2 Lg. 9A-C0220-1031J 8
39 Screw, Rd. Hd., Slotted, 6-32 x 3/8 Lg. 9A-C0111-0015J 2
43 Bracket, Mounting 9A-C0273-0001C 2
44 Screw, Hex Head, 1/4-28 x 1/2 Lg. 9A-C0116-1011J 4
45 Washer, Ext. Tooth, 1/4 9A-C0003-0068K 4
46 Plug 9A-C0224-0269C 1
47 O-ring (Torque Tube), EPT 9A-C0001-1068R 1
48 Ring, Grip 9A-C0087-1029T 1
49 Washer, Split Lock, 3/8 9A-C0003-0093K 2
50

O-ring (Header), EPT 9A-C0001-1066R

1

30

Section 4 Model 580A Differential Pressure Switch

Table4.2—PartsList,Model580A-2BlindSwitchwithoutIndicator

Item Description Part No.

Per

Unit

51 Nut, Hex., 3/8-16 9A-C0500-0039J 2
52 O-ring (Lens/Cover), EPT 9A-C0001-1057R 1
53 O-ring (Plug), EPT 9A-C0001-1051R 1
55 Screw, Rd. Hd., Slotted, 6-32 x 3/16 Lg. 9A-C0117-0013J 2
57 Screw, Flat Hd., 10-32 x 1/2 Lg. 9A-C0240-0015J 6
58 Washer, Split Lock, #8 9A-C0003-0036K 2
60 Washer, Split Lock, #6 9A-C0003-0038K 2
72 Case Bushing 9A-C0580-1101C 1
* Silicone Grease 9A-C0002-1003U A/R
** Thread Lubricant, Mokykote 9A-C0002-0010U A/R
*** Locktite 222 9A-C0007-1033U A/R

Notes:
*Prior to installation, lubricate O-rings (Items 47, 50, 52 and 53) with silicone grease.
**Apply thread lubricant to threads of Item 16 (set screw) and Item 38 (cap screw) before installing.
***Apply Locktite to Item 19 (set screw) when installing into the mounting plate.

31

Model 580A Differential Pressure Switch Section 4

Table 4.3 presents torque requirements for the switch assembly fasteners.

Table4.3—TorqueRequirementsforSwitchAssemblyFasteners

(SeeFigures4.1and4.2forpartidentication)

Item Description Part No. Per

Unit

Torque*

9 Lock Screw 9A-C0580-1017C 2 Tight

10 Screw, B.H. Slotted, 3-48 x 3/16

Lg.

9A-C0117-0007J 6 Tight

12 Screw, B.H. Slotted, 8-32 x 3/16

Lg.

9A-C0117-1001J 2 Tight

16 Set Screw, 6-32 x 1/4 Lg. 9A-C0320-1010J 1 Snug

24 Terminal Strip Screw, 5-40 x 1/4 N/A 10 Snug

26 Movement Assembly Riser 9A-C0277-0035C 2 Tight

38 Screw, Cap: 10-32 x 1 Lg. (select one) 8 35-45 in-lb

Model 580A-0 (with glass lens)

Model 580A-2 (blind)

9A-C0220-1062J

9A-C0220-1031J

39 Screw, Rd. Hd., Slotted, 6-32 x

3/8 Lg.

9A-C0111-0015J 2 Tight

40 Screw, Pan. Hd., Slotted, 4-40

x 1/8 Lg. (Model 580A-0 only),
bottom hole in scale plate not used

9A-C0119-1116J 5 Snug

41 Screw, B.H., Slotted, 4-40 x 3/16

Lg. (Model 580A-0 only)

9A-C0117-0012J 1 Tight

42 Screw, B.H., Slotted, 6-32 x 3/16

Lg. (Model 580A-0 only)

9A-C0117-0013J 2 Tight

44 Screw, Hex Head, 1/4-28 x 1/2 Lg. 9A-C0116-1011J 4 8-9 ft-lb

46 Plug 9A-C0224-0269C 1 Snug

51 Nut, Hex., 3/8-16 9A-C0500-0039J 2 22-25 ft-lb

55 Screw, Rd. Hd., Slotted, 6-32 x

3/16 Lg.

9A-C0117-0013J 2 Tight

57 Screw, Flat Hd., 10-32 x 1/2 Lg. 9A-C0240-0015J 6 33-35 in-lb

* Snug denotes 1/16 (approx) turn past head contact.
Tight denotes 1/8 (approx) turn past head contact.

32

Section 4 Model 580A Differential Pressure Switch

33

Model 580A Differential Pressure Switch Section 5

Section5—DimensionalDrawings

PRESSURE CONNECTIONS

CENTER OF GRAVITY

(WALL)

7 1/2

(190.5)

5

(127.0)

2 3/4

(69.9)

3 7/8

(98.4)

3/4

(19.1)

1/2

(12.7)

D

A

CASE

DPU

Figure 5.1—Model 580A, side view

CENTER OF GRAVITY

LOW PRESSURE

HOUSING

4 SLOTS
3/8 (9.5) X
11/16 (17.5)

BOTTOM PRESSURE
CONNECTIONS
1/4 NPT STANDARD

PRESSURE
HOUSING

HIGH PRESSURE
HOUSING

TOP PRESSURE CONNECTIONS

1/2 NPT STANDARD

3 1/2

(88.9)

2 13/16

(71.4)

1 13/32

(35.7)

2 5/16
(58.7)

DPU

B

C

E

Figure 5.2—Model 580A, rear view

34

Section 5 Model 580A Differential Pressure Switch

Table 5.1—Model 580A Dimensions

DPU SWP

DIM A

(580A-0)

DIM A

(580A-2)

DIM B DIM C DIM D DIM E

.5/1.5K 7 5/16

185.7)

6 3/4

(171.4)

6 15/16

(176.2)

5 5/8

(142.9)

5 1/16

(128.67)

2 15/16

(74.6)

3/6K 7 5/16

(185.7)

6 3/4

(171.4)

7 5/16

(185.7)

6

(152.4)

5 3/16

(131.8)

3 1/4

(82.6)

IMPORTANT: For DPU dimensional information, refer to DPU Dimensional Drawing,

page A-19.

A-1

Model 580A Differential Pressure Switch Appendix A

AppendixA—Model224DPU

DPUDescription

The Barton Model 224 Differential Pressure Unit (DPU) is a mechanical
device that measures differential pressure relative to a gas or liquid owing
through a process system, or to the level of a liquid contained in a process
vessel.

For process ow measurements, the DPU is connected across a primary mea­suring device (e.g., venturi, orice plate, or ow tube) located in the process

system.

For liquid level measurements, the DPU may be connected in a variety of

ways.

The Model 224 DPU is a dual bellows assembly enclosed within pressure

housings. The dual bellows assembly consists of two opposing internally con-

nected liquid-lled bellows, a center block, range springs, overrange valves,

and a torque tube assembly.

The pressure housings are connected by pipe or tubing to the primary measur-

ing device located in the system piping. Variations in differential pressure

within the pressure housings cause the bellows to expand or contract laterally.

The linear movement of the bellows causes the torque tube to rotate, which

actuates the process monitoring instrument.

The process monitoring instrument may be an indicator, a switch, a transmit-

ter, a recorder, or other process control device.

Specications

The Model 224 DPU is available in various pressure ratings to measure to
specic ranges between 0-30 inches of water column and 0-1000 psi, with
safe working pressure (SWP) ratings of 500, 1000, 1500, 3000 and 6,000 psi.

See Table A.1, page A-3.

The Model 224 Bellows Unit Assembly (BUA) is available in three bellows
diameters: 1 5/8 inch, 3/4 inch and 5/8 inch (shown in Figure A.1, page A-2).

The BUA with 1 5/8-inch bellows accommodates differential pressures to 60

psi. The range springs are contained within the bellows and do not come in
contact with the measured liquid.

A-2

Appendix A Model 580A Differential Pressure Switch

The BUA with 3/4-inch bellows accommodates differential pressures up to

400 psi. The range springs are grouped around the outside of the bellows and
must be of a material that is compatible with the liquid being measured.

The BUA with 5/8-inch bellows accommodates differential pressure ranges
up to 1000 psi. Like the BUA with 3/4-inch bellows, the range springs are

grouped outside the bellows.

The Model 224 DPU general specications are presented in Table A.1, page A-3.

Figure A.1—Bellows Unit Assembly (BUA)

A-3

Model 580A Differential Pressure Switch Appendix A

TableA.1—Model224DPUSpecications

SWP

psi(bar)

BODY AVAILABLE DIFFERENTIAL PRESSURE RANGES

HousingMaterial

StainlessSteel/InconelBellows InconelBellows

1-5/8"(41.3mm)O.D. 3/4"(19.1mm)O.D. 5/8"(15.9mm)O.D.

500
(34.5)

Stainless Steel (316)
Copper Nickel (70-30)

0-30" (0-762 mm) w.c.
to 0-60 psi (0-3.8 bar)

0-61 psi (0-3.9 bar) to
0-400 psi (0-27.6 bar)

0-400 psi (0-27.6 bar) to
0-500 psi (0-34.5 bar)

1,000
(68.9)

Copper Nickel (70-30)
(MIL-C-15726)

0-60" (0-1524 mm) w.c.
to 0-60 psi (0-3.8 bar)

0-61 psi (0-3.9 bar) to
0-400 psi (0-27.6 bar)

0-400 psi (0-27.6 bar) to
0-1000 psi (0-68.9 bar)

1,500
(103.4)

Stainless Steel (316) 0-60" (0-1524 mm) w.c.

to 0-60 psi (0-3.8 bar)

0-61 psi (0-3.9 bar) to
0-400 psi (0-27.6 bar)

0-400 psi (0-27.6 bar) to
0-1000 psi (0-68.9 bar)

3,000
(206.9)

Stainless Steel (316) 0-60" (0-1524 mm) w.c.

to 0-60 psi (0-3.8 bar)

0-61 psi (0-3.9 bar) to
0-400 psi (0-27.6 bar)

0-400 psi (0-27.6 bar) to
0-1000 psi (0-68.9 bar)

6,000
(413.8)

Stainless Steel (316) 0-60" (0-1524 mm) w.c.

to 0-60 psi (0-3.8 bar)

0-61 psi (0-3.9 bar) to
0-400 psi (0-27.6 bar)

0-400 psi (0-27.6 bar) to
0-1000 psi (0-68.9 bar)

Net Volume
(cu. in.)

L.P. Head 1.66" (42.2 mm) 2.51" (63.8 mm) 2.61" (66.3 mm)

H.P. Head 1.55" (39.4 mm) 2.42" (61.5 mm) 2.50" (63.5 mm)

Displacement in cu. in. for full-scale
travel

0.14" (3.6 mm) 0.03" (0.8 mm) 0.025" (0.6 mm)

Pressure
Ranges

Zero center or split ranges available on special order (e.g. a 0-60" w.c. (0-1524 mm) range may be
ordered 30-0-30" w.c. (762-0-762 mm) or 15-0-45" w.c. (381-0-1143 mm); Absolute pressure ranges
available from 30" w.c. (762 mm) to 400 psi (41.4 bar).

Pressure
Connections

1/4 NPT top x 1/4 NPT bottom

1/4 NPT top x 1/2 NPT bottom

1/2 NPT top x 1/4 NPT bottom

1/2 NPT top x 1/2 NPT bottom

Performance

Torque Tube Rotations (full- scale DP)

Temperature Limits

Maximum Non-linearity:

0-30" wc to 0-150 psi

0-150 psi to 0-400 psi

0-400 psi to 0-600 psi

0-600 psi to 0-1,000 psi

Repeatability

8º ± 10%

-40ºF (-40ºC) to 180ºF (+82ºC)

± 1-1/2%

± 2%

± 4%

± 6-1/2%

± 0.2% of full scale

Dimensions Outline dimension drawings available upon request.

Theory of Operation

The Barton Model 224 DPU shown in Figure A.2, page A-4, measures the differ-
ential pressure in a process system relative to process functions and produces

a mechanical output that actuates process monitoring instruments and process

control devices.

The high-pressure (HP) housing is connected by pipe or tubing to the high­pressure side of the primary measuring device. The low-pressure (LP) hous­ing is connected to the low-pressure side of the primary device.

As pressure changes within the housings, the bellows move laterally. The
connecting drive arm follows the motion of the bellows, and twists the torque
tube. The rotation of the torque tube shaft provides the mechanical motion

A-4

Appendix A Model 580A Differential Pressure Switch

Figure A.2—Model 224 DPU components

required to actuate process instruments, such as recorders, indicators, trans­mitters, controllers, and switches.

If the bellows are subjected to a pressure greater than the range of the DPU,
they move their normal travel range and a small amount of overtravel until
the overrange valve seals against the valve seat. As the valve closes, the ll
liquid is trapped in the bellows. Since the ll uid is essentially noncompress-

ible, the bellows are fully supported and will not be damaged regardless of the

overpressure (up to the full rated pressure of the instrument) applied to them.
Also, since dual overrange valves are used, full protection against overrange
is provided in either direction.

An additional convolution in the high-pressure bellows provides for expan­sion or contraction of the ll uid relative to ambient temperature changes.
This extra convolution acts as an accumulator, permitting the ll uid to
change volume without materially affecting the pressure within the bellows or

changing the physical relationship of the two bellows.

DPU Installation

General

Inspect the instrument after unpacking it to detect any damage that may have

occurred during shipment.

IMPORTANT: The DPU was checked for accuracy at the factory. Do not change any of

the settings during examination or accuracy could be affected.

A-5

Model 580A Differential Pressure Switch Appendix A

For applications requiring special cleaning/precautions, a polyethylene bag

is used to protect the instrument from contamination. Remove this bag only

under conditions of extreme cleanliness.

Mounting

Mount the instrument to a solid support with four 5/16-inch (8 mm) grade
5 or better bolts, and apply 17 ft-lb of torque. To minimize relative motion
of the DPU connections, use a mounting structure that will also support the

interfacing process tubing.

Mounting structures shall be designed to avoid resonance and/or minimize
resulting amplication below 33 Hz. Response spectra at the mounting

surface of the instrument shall not exceed those in the applicable nuclear

qualication report.

Piping

!

 WARNING:Highpressurehazard.Topreventpersonalinjuryordamage

toequipment,directallpipingawayfromtheoperatorwhileconnecting
theDPUtosystempiping.

IMPORTANT: Do not share lling or vapor return lines with DPU piping lines.

Observe the following standard practices and refer to the piping diagrams on
page A-6 when installing piping:

• Shorten the distance between the primary measuring device and the DPU
as much as possible. Distances exceeding 100 ft are not recommended.
For distances up to 50 ft, use 1/4-in. pipe or tubing. For runs of 50 to
100 ft, use 1/2-in. pipe or tubing. The recommended limitation does not

apply if an air purge or blow-back system is used.

• Slope all piping at least 1 inch per linear foot to avoid liquid or gas
entrapment.

• If process media exceeding +200ºF (+93.3ºC) must be measured, install

2 ft of uninsulated piping between the DPU and the primary measuring
device for each 100ºF (37.8ºC) in excess of +180ºF (+82.2ºC).

• Assure that the temperature of the DPU never exceeds 180°F (+82.2°C).
When steam tracing is necessary, the steam pressure should not exceed
5 pounds per square inch and insulation should not be used. If pressure
must exceed 5 pounds per square inch, limit the length of tubing around

the DPU to two turns and do not insulate.

• When severe pulsation is present, install a suitable pulsation dampening
device upstream of the DPU.

A-6

Appendix A Model 580A Differential Pressure Switch

• Mount the DPU on a solid support to minimize vibration. Tighten all
points, using a suitable sealant compound; leaks in piping can cause

measurement errors.

• Rotate the housing as necessary to place the pressure connection in the

proper position. The DPU has connections in the pressure housings to
accommodate various pipe sizes (refer to DPU Assembly Drawing and

Parts List, page A-17).

• Install a valve manifold between the DPU and the source of differential
pressure to facilitate operation and checking of the DPU.

• Install shutoff and bypass valves so they are accessible from the front of
the instrument. Locate block valves at the source of differential pressure.

Piping Diagrams

Diagrams for typical and special ow applications are presented on the fol­lowing pages. Use the diagram best suited for the application as a guide for
piping conguration.

BLOCK VALVES

PRIMARY DEVICE

STATIC PRESSURE

CONNECTION

(USE ONLY ONE)

BYPASS

VALVES

VENT VALVE

SHUT-OFF

VALVES

DPU

Figure A.3—Gas Flow, DPU Above Run

BLOCK

VALVES

PRIMARY
DEVICE

STATIC PRESSURE

CONNECTION

(USE ONLY ONE)

BYPASS
VALVES

VENT
VALVE

SHUT-OFF

VALVES

DPU

DRIP POTS

Figure A.4—Gas Flow, DPU Below Run

A-7

Model 580A Differential Pressure Switch Appendix A

BLOCK VALVES

PRIMARY
DEVICE

BYPASS
VALVE

SHUT-OFF

VALVES

DPU

Figure A.5—Gas Flow, Hydrates Present

DPU

PLUGS

BLOCK
VALVES

CONDENSING
RESERVOIR

PRIMARY

DEVICE

SHUT-OFF
VALVES

VENT
VALVES
(OPTIONAL)

Figure A.6—Steam Flow, DPU Below Run

BLOCK
VALVES

PRIMARY DEVICE

DRIP POTS

STATIC PRESSURE

CONNECTION

(USE ONLY ONE)

BYPASS
VALVES

VENT

VALVE

SHUT-OFF

VALVES

DPU

Figure A.7— Liquid Flow, DPU Above Run

A-8

Appendix A Model 580A Differential Pressure Switch

BLOCK
VALVES

PRIMARY

DEVICE

BYPASS
VALVE

FILL TEE AND
VENT VALVE
FOR HOT OR

GASSY LIQUIDS

SHUT-OFF
VALVES

DPU

Figure A.8—Liquid Flow, DPU Below Run

BLOCK

VALVES

SEAL
POTS

PRIMARY
DEVICE

BYPASS

VALVE

SHUT-OFF

VALVES

DPU

Figure A.9—Corrosive Liquid Flow

DRAIN
VALVE

BLOCK
VALVE

HIGH-PRESSURE

DPU

BLOCK
VALVE

SHUT-OFF

VALVE

VENT

VALVE

SHUT-OFF
VALVE

Figure A.10—Cool Non-Condensing Liquid, DPU Level with Tank Bottom

A-9

Model 580A Differential Pressure Switch Appendix A

HIGH-PRESSURE

SHUT-OFF
VALVE

BLOCK
VALVE

DRAIN
VALVE

DPU

SHUT-OFF

VALVE

BLOCK

VALVE

Figure A.11—Cool Non-Condensing Liquid, DPU Below Tank

HIGH-PRESSURE

SHUT-OFF
VALVE

REFERENCE
LEG

2" CROSS

BYPASS

VALVE

VENT
VALVE

BLOCK
VALVE

BLOCK
VALVE

DPU

SHUT-OFF
VALVE

DRAIN VALVE

Figure A.12—DPU Bottom Tank with Reference Leg

A-10

Appendix A Model 580A Differential Pressure Switch

SHUT-OFF
VALVE

LOW-PRESSURE

DRAIN
VALVE

BLOCK
VALVE

INVERTED "U"

GAS TRAP

MINIMUM LENGTH
6 INCHES

DPU

BLOCK VALVE

VAPOR GENERATOR

Figure A.13—Liquid CO2

LOW-PRESSURE

HIGH-PRESSURE

SHUT-OFF
VALVE

INVERTED "U"
GAS TRAP

VAPOR GENERATOR
FLAT TUBULAR SPIRAL

IN OUTER 1/3 OF TANK

INSULATION KEEP
DEAD LEG BETWEEN
TANK AND SPIRAL
5 INCHES OR LESS

MINIMUM LENGTH

12 INCHES

BLOCK VALVE

BLOCK
VALVE

DPU

Figure A.14—Cryogenic Liquids

A-11

Model 580A Differential Pressure Switch Appendix A

SHUT-OFF VALVES

BLOCK VALVES

HIGH PRESSURE

GAS
SUPPLY

SIGHT FLOW

GAGE

BYPASS VALVE

DPU

INPUT GAS
REGULATOR

Figure A.15—Bubbler System

SHUT-OFF VALVES

BLOCK VALVES

HIGH-PRESSURE

GAS
SUPPLY

INPUT GAS
REGULATOR

SIGHT FLOW GAGES
WITH THROTTLING VALVES

BYPASS VALVE

DPU

Figure A.16—Liquid Specic Gravity

A-12

Appendix A Model 580A Differential Pressure Switch

Startup

Observe the following practices when starting up a process monitoring instru­ment:

1. Close the block valves.

2. Perform a zero check on the instrument as follows.
a. Open the bypass valve(s), then open one shutoff valve. This proce-

dure equalizes the pressure between both sides of the instrument.

The instrument should indicate zero.

b. If the instrument does not indicate zero, check for gas or liquid

entrapment in the DPU piping or in the DPU (depending on the
orientation of the piping layout and service).

c. If necessary, adjust the pen or pointer by turning the zero adjust knob

on the instrument until the pointer indicates zero.

IMPORTANT: For gas service, perform a zero check with both block valves closed. If

the gas ow is pulsating, a standing wave effect may occur in the pro­cess line which can displace the indicator and appear as a zero error.

3. Check the manifold and piping for leaks as follows.
a. Open the bypass valve(s), then open one shutoff valve to pressurize

the instrument.
b. Close the shutoff valve and the bypass valve.
c. Observe the instrument for pen or pointer movement, up or down the

scale, which could indicate leakage.

IMPORTANT: Do not subject the DPU to unnecessary shock or overrange pressure

during operations.

DPU Maintenance

Periodically inspect the integrity of the DPU piping. Tighten all pipe joints as

necessary.

If the instrument is used in services where solids or semi-solids may accumu­late inside the pressure housings, periodically inspect and clean the DPU. See
DPU Cleaning and Inspection below.

For calibration procedures for the Model 580A Differential Pressure Switch,
see Section 3, page 11.

Required Tools

A screwdriver is needed for adjusting screws in the mounting bracket, and a

50-lb torque wrench is recommended for adjusting pressure housing bolts.

A-13

Model 580A Differential Pressure Switch Appendix A

!

 WARNING:TheunexpectedreleaseofinternalpressurefromaDPUcan

resultinseverepersonalinjury,deathorpropertydamage.Beforeremov­ingDPUhousingbolts,performapressurecheck.Thisisespeciallyim­portantiftheDPUisinstalledinagasapplicationwithworkingpressures
exceeding200psig.

DPU Cleaning and Inspection

1. Remove the DPU from service.

2. Check for internal DPU pressure as follows:
a. Back off all housing bolts 4 turns.
b. Attempt to move the housing in and out along the bolts

If the housing moves freely, no pressure is present. Servicing or

repair may continue.

If the housing does not move freely, the bellows may be pressurized.

Immediately stop all disassembly, tighten the housing bolts, and

return the unit to the factory or authorized service center for repair.
Tag the unit and specify "Gas in the Bellows."

3. Carefully remove the pressure housing bolts and pressure housings.

IMPORTANT: If a heavy buildup of solids or semi-solids has accumulated inside the

housing, rapid removal of the housing may damage the bellows convolu­tions.

4. Remove the accumulation from between the bellows convolutions and
from the inside of the housings. Use a solvent if possible. Do not use a
hard or sharp instrument to clean between convolutions.

5. Check for broken range springs and replace as necessary.

6. Replace the housings and the O-rings.

IMPORTANT: It is recommended that new O-rings be used whenever pressure hous-

ings are replaced.

7. Reinstall housing bolts and apply torque as required. See Table A.2 for
appropriate torque values.

A-14

Appendix A Model 580A Differential Pressure Switch

TableA.2—BoltTorqueRatings

HOUSING BOLT

LUBE

(Note1)

TORQUE

LB-FT

(Note2)

ROTATION

(Degrees)

(Note3)

SWP MATL. MATL. SIZE

500 SST SST 1/4-28 x 2.5 YES 12-14 180

500 CuNi Monel 1/4-28 x 2.5 YES 9-11 180

1,000 Cu-Ni Monel 1/4-28 x 2.5 YES 9-11 180

1,500 SST SST 1/4-28 x 2.5 YES 12-14 180

3,000 SST SST 3/8-24 x 2.5 YES 35 90

6,000 SST SST 3/8-24 x 2.5 YES 40 135

Notes: (1)Lubricant: Molykote G paste, graphite-base grease, or similar lubricants. Lube rst
thread only.(2) Torque on bolts is accomplished in 3 or 4 steps. Tighten uniformly. (3) Cameron
recommendsusingatorquewrenchwheneverinstallinghousingbolts.Rotation of bolt head is
measured after bolt is "snug" (approx. 1/16 turn past head contact) with approximately 2 ft-lb torque.
Do not exceed this rotation. To tighten bolts without torque wrench, use the following values: 1/4 turn
= 90º, 1/2 turn = 180º

Changing the DPU Range

To change the range of the DPU, replace the BUA with a unit of the desired

range.

Replacing the Bellows Unit Assembly (BUA)

!

 WARNING:ReviewthewarningsunderDPUCleaningandInspection,

pageA-13,beforeperformingthisprocedure.

IMPORTANT: Do not loosen the drive arm hole plug located on the top of the BUA

center block when removing the mounting bracket. If the plug is loos­ened, the ll uid in the bellows will be lost and the unit will be inoper­able.

1. Disconnect the DPU piping, remove the process monitoring instrument
from service, and remove the mounting bracket from the DPU.

IMPORTANT: See the manual for the process monitoring instrument for particular

components that must be removed to gain access to the DPU mounting
fasteners.

2. Loosen the drive arm from the process monitoring instrument and
separate it from the torque tube shaft. Do not disconnect the instrument
linkage.

3. Perform a pressure check of the DPU as follows:
a. Back off all housing bolts 4 turns.
b. Attempt to move the housing in and out along the bolts.
If the housing moves freely, no pressure is present. Servicing or
repair may continue.

If the housing does not move freely, the bellows may be pressurized.

A-15

Model 580A Differential Pressure Switch Appendix A

Immediately stop all disassembly, tighten the housing bolts, and

return the unit to the factory or authorized service center for repair.
Tag the unit and specify "Gas in the Bellows."

4. Carefully remove the pressure housing bolts and pressure housings.

IMPORTANT: It is recommended that new O-rings be used whenever pressure hous-

ings are replaced.

5. Install the pressure housings onto the new BUA and attach with appropri­ate housing bolts (see Table A.2, page A-14, for torque requirements).

6. Reattach the mounting bracket to the DPU.

7. Re-attach the DPU to the process monitoring instrument and install the
instrument into service in reverse order of removal. For instructions on
attaching the Model 580A Differential Pressure Switch drive arm to the

torque tube, see Section 3, page 11.

8. Calibrate the instrument per the instructions in Section 3, page 11.

DPUTroubleshooting

Table A.3 provides a description of commonly reported problems, probable
causes, and corrective actions for use in troubleshooting issues involving the
Model 224 DPU.

See Table 3.1, page 23, for Model 580A Differential Pressure Switch trouble-
shooting information.

TableA.3—TroubleshootingTips

Problem Possible

Source

Probable Cause CorrectiveAction

Low or No

Indication

Primary
Element or
DPU

Orice installed backwards or oversized Replace orice

Flow blocked upstream from run Clean out run or open

valve

Loss of liquid in reference leg (liquid level) Rell reference leg

Density changes in process media or
reference leg

Rell reference leg with

same density liquid as
process media

Piping from
Primary
Element to
DPU

Pressure tap holes plugged and/or piping
plugged

Clean out piping

Bypass valve open or leaking Close bypass valve(s)

or repair leaks

Liquids or gases trapped in piping Vent piping

Block or shutoff valves closed Open block or shutoff

valves

Piping leaks on high pressure side Repair leaks

A-16

Appendix A Model 580A Differential Pressure Switch

TableA.3—TroubleshootingTips

Problem Possible

Source

Probable Cause CorrectiveAction

Low or No
Indication

Bellows Unit Housing lled with solids restricting bel-

lows movement

Clean out housing

Gas (liquid service) or liquid (gas service)
trapped in housing

Vent housing

High pressure housing gasket leaks Replace gasket

DPU tampered with Return BUA for repair

High
Indication

Primary
Source

Orice partially restricted or too small Clean out or replace

Primary
Element to
DPU piping

Piping leaks on low pressure side Repair leaks

Bellows Unit Gas (liquid service) or liquid (gas service)

trapped in housing

Vent housing

Low pressure housing gasket leaks Replace gasket

Range spring broken or DPU tampered
with

Return BUA for repair

Erratic
Indication

Primary
Element

Flow pulsating Install dampening

device upstream of
DPU run

Primary
Element to
DPU piping

Liquid (gas service) or gas bubble (liquid
service) trapped in piping

Remove

Vapor generator incorrectly installed Re-pipe

Reference leg gassy or liquid vaporizing See piping instructions

Bellows Unit Obstructed bellows travel Clean bellows

Gas trapped in DPU high pressure or low
pressure housing

Remove (see startup
procedure)

A-17

Model 580A Differential Pressure Switch Appendix A

DPUAssemblyDrawingandPartsList

Figure A.17—Model 224 DPU assembly drawing

A-18

Appendix A Model 580A Differential Pressure Switch

Table A.4—Model 224 DPU Parts List

Item Description Part No. Qty

1 Bellows Unit Assembly, 3/4" or 5/8" 1

Bellows Unit Assembly, 1-5/8"

*2 O-Ring, Housing Gasket 2

Viton 9A-C0001-0039R

EPT 9A-C0001-1054R

3 Bracket, Mounting 9A-C0273-0001C 2

4 Washer, ET Lock, 1/4" SST 9A-C0003-0068K 4

5 Screw, Hex Hd. SST, 1/4-28 x 1/2" 9A-C0116-1011J 4

6 Housing, Pressure 2

Housing, SST, .5/1.5K SWP, 1/4 x 1/4 NPT 9A-C0224-1543C

Housing, SST, .5/1.5K SWP, 1/4 x 1/2 NPT 9A-C0224-1610C

Housing, SST, .5/1.5K SWP, 1/2 x 1/2 NPT 9A-C0224-1579C

Housing, SST, .5/1.5K SWP, Absolute 9A-C0224-1618C

Housing, SST, 3/6K SWP, 1/4 x 1/4 NPT 9A-C0224-1556C

Housing, SST, 3/6K SWP, 1/4 x 1/2 NPT 9A-C0224-1608C

Housing, SST, 3/6K SWP, 1/2 x 1/2 NPT 9A-C0224-1580C

Housing, CuNi, .5/1K SWP, 1/4 x 1/4 NPT 9A-C0224-1581C

Housing, CuNi, .5/1K SWP, 1/4 x 1/2 NPT 9A-C0224-1616C

Housing, CuNi, .5/1K SWP, 1/2 x 1/2 NPT 9A-C0224-1655C

Housing, CuNi, .5/1K SWP, Absolute 9A-C0224-1651C

7 Screw, Housing 4

Soc Head Screw, 1/4-28 x 2-1/2, SST (17-4)

(for .5/1.5K SST units)

9A-C0220-1017J

Soc Head Screw, 3/8-24 x 2-1/2, SST (17-4)

(for 3/6K SST units)

9A-C0220-1014J

Soc Head Screw, 1/4-28 x 2-1/2, Monel

(for .5/1K CuNi units)

9A-C0220-0045J

8 Plug, Pipe 2

Pipe Plug, SST, 1/4 NPT 9A-C0199-0214C

Pipe Plug, SST, 1/2 NPT 9A-C0199-0215C

Pipe Plug, Monel, 1/4 NPT 9A-C0199-0235C

Pipe Plug, Monel, 1/2 NPT 9A-C0199-0234C

9 Spring Pin 9A-C0003-0002T 4

* Indicates recommended spare parts.

A-19

Model 580A Differential Pressure Switch Appendix A

DPUDimensionalDrawing

Figure A.18—Model 224 DPU dimensional drawing

Table A.5—Model 224 DPU Dimensions

SWP

(psi)

Dim"A"
in.(mm)

Dim"B"
in.(mm)

DIM"C"
in.(mm)

DIM"D"
in.(mm)

DIM"E"

in.(mm)

500 or
1500

2-15/16

(74.6)

5-5/8

(142.9)

6-15/16

(176.2)

4-3/4

(120.6)

3-1/8

(79.4)

6000 3-1/4

(82.6)

6

(152.4)

7-5/16

(185.7)

4-55/64

(123.4)

3

(76.2)

A-20

Appendix A Model 580A Differential Pressure Switch

A-21

Model 580A Differential Pressure Switch Appendix A

Product Warranty

A. Warranty

Cameron International Corporation ("Cameron") warrants that at the time of shipment, the prod-

ucts manufactured by Cameron and sold hereunder will be free from defects in material and

workmanship, and will conform to the specications furnished by or approved by Cameron.

B. Warranty Adjustment

(1) If any defect within this warranty appears, Buyer shall notify Cameron immediately.

(2) Cameron agrees to repair or furnish a replacement for, but not install, any product which

within one (1) year from the date of shipment by Cameron shall, upon test and examina­tion by Cameron, prove defective within the above warranty.

(3) No product will be accepted for return or replacement without the written authorization of

Cameron. Upon such authorization, and in accordance with instructions by Cameron, the
product will be returned shipping charges prepaid by Buyer. Replacements made under
this warranty will be shipped prepaid.

C. Exclusions from Warranty

(1) THE FOREGOING WARRANTY IS IN LIEU OF AND EXCLUDES ALL OTHER

EXPRESSED OR IMPLIED WARRANTIES OF MERCHANTABILITY, OR FITNESS FOR
A PARTICULAR PURPOSE, OR OTHERWISE.

(2) Components manufactured by any supplier other than Cameron shall bear only the war-

ranty made by the manufacturer of that product, and Cameron assumes no responsibility
for the performance or reliability of the unit as a whole.

(3) "In no event shall Cameron be liable for indirect, incidental, or consequential damages

nor shall the liability of Cameron arising in connection with any products sold hereunder
(whether such liability arises from a claim based on contract, warranty, tort, or otherwise)
exceed the actual amount paid by Buyer to Cameron for the products delivered hereun­der."

(4) The warranty does not extend to any product manufactured by Cameron which has

been subjected to misuse, neglect, accident, improper installation or to use in violation of
instructions furnished by Cameron.

(5) The warranty does not extend to or apply to any unit which has been repaired or

altered at any place other than at Cameron's factory or service locations by persons not
expressly approved by Cameron.

Product Brand

Barton® is a registered trademark of Cameron International Corporation ("Cameron").
Tefzel® is a registered trademark of E.I. DuPont de Nemours & Co., Inc.