Rosemount Manual: Manual: Flame Photometric Detector For GC Hardware Reference Manual (contains information for the newer 700XA and 1500XA Gas Chromatographs) Manuals & Guides

FPD for Gas Chromatographs

Hardware Reference Manual

7R00370-H01

Revision B

January 2018

Introduction

NOTICE

ROSEMOUNT (“SELLER”) SHALL NOT BE LIABLE FOR TECHNICAL OR EDITORIAL ERRORS IN THIS MANUAL OR
OMISSIONS FROM THIS MANUAL. SELLER MAKES NO WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO THIS MANUAL
AND, IN NO EVENT, SHALL SELLER BE LIABLE FOR ANY SPECIAL OR CONSEQUENTIAL DAMAGES INCLUDING, BUT NOT
LIMITED TO, LOSS OF PRODUCTION, LOSS OF PROFITS, ETC.

PRODUCT NAMES USED HEREIN ARE FOR MANUFACTURER OR SUPPLIER IDENTIFICATION ONLY AND MAY BE
TRADEMARKS/REGISTERED TRADEMARKS OF THESE COMPANIES.

THE CONTENTS OF THIS PUBLICATION ARE PRESENTED FOR INFORMATIONAL PURPOSES ONLY, AND WHILE EVERY
EFFORT HAS BEEN MADE TO ENSURE THEIR ACCURACY, THEY ARE NOT TO BE CONSTRUED AS WARRANTIES OR
GUARANTEES, EXPRESSED OR IMPLIED, REGARDING THE PRODUCTS OR SERVICES DESCRIBED HEREIN OR THEIR USE
OR APPLICABILITY. WE RESERVE THE RIGHT TO MODIFY OR IMPROVE THE DESIGNS OR SPECIFICATIONS OF SUCH
PRODUCTS AT ANY TIME.

SELLER DOES NOT ASSUME RESPONSIBILITY FOR THE SELECTION, USE, OR MAINTENANCE OF ANY PRODUCT.
RESPONSIBILITY FOR PROPER SELECTION, USE, AND MAINTENANCE OF ANY SELLER PRODUCT REMAINS SOLELY WITH
THE PURCHASER AND END-USER.

THE EMERSON LOGO IS A TRADEMARK AND SERVICE MARK OF EMERSON ELECTRIC CO. ROSEMOUNT IS A TRADEMARK
OF ONE OF THE EMERSON FAMILY OF COMPANIES.

©2017

ROSEMOUNT

HOUSTON, TX

USA

All rights reserved. No part of this work may be reproduced or copied in any form or by any means–graphic, electronic,
or mechanical–without first receiving the written permission of Rosemount Houston, Texas, U.S.A.

WARRANTY

LIMITED WARRANTY: Subject to the limitations contained in Section 2 herein and except as otherwise expressly
provided herein, Rosemount (“Seller”) warrants that the firmware will execute the programming instructions
provided by Seller, and that the Goods manufactured or Services provided by Seller will be free from defects in
materials or workmanship under normal use and care until the expiration of the applicable warranty period. Goods are
warranted for twelve (12) months from the date of initial installation or eighteen (18) months from the date of
shipment by Seller, whichever period expires first. Consumables and Services are warranted for a period of 90 days
from the date of shipment or completion of the Services. Products purchased by Seller from a third party for resale to
Buyer (“Resale Products”) shall carry only the warranty extended by the original manufacturer. Buyer agrees that Seller
has no liability for Resale Products beyond making a reasonable commercial effort to arrange for procurement and
shipping of the Resale Products. If Buyer discovers any warranty defects and notifies Seller thereof in writing during
the applicable warranty period, Seller shall, at its option, promptly correct any errors that are found by Seller in the
firmware or Services, or repair or replace F.O.B. point of manufacture that portion of the Goods or firmware found by
Seller to be defective, or refund the purchase price of the defective portion of the Goods/Services. All replacements or
repairs necessitated by inadequate maintenance, normal wear and usage, unsuitable power sources, unsuitable
environmental conditions, accident, misuse, improper installation, modification, repair, storage or handling, or any
other cause not the fault of Seller are not covered by this limited warranty, and shall be at Buyer's expense. Seller shall
not be obligated to pay any costs or charges incurred by Buyer or any other party except as may be agreed upon in
writing in advance by an authorized Seller representative. All costs of dismantling, re-installation and freight and the
time and expenses of Seller's personnel for site travel and diagnosis under this warranty clause shall be borne by Buyer
unless accepted in writing by Seller. Goods repaired and parts replaced during the warranty period shall be in warranty
for the remainder of the original warranty period or ninety (90) days, whichever is longer. This limited warranty is the
only warranty made by Seller and can be amended only in a writing signed by an authorized representative of Seller.
Except as otherwise expressly provided in the Agreement, THERE ARE NO REPRESENTATIONS OR WARRANTIES OF ANY
KIND, EXPRESSED OR IMPLIED, AS TO MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE, OR ANY OTHER
MATTER WITH RESPECT TO ANY OF THE GOODS OR SERVICES.
not covered by our guarantee.

It is understood that corrosion or erosion of materials is

LIMITATION OF REMEDY AND LIABILITY: SELLER SHALL NOT BE LIABLE FOR DAMAGES CAUSED BY DELAY IN
PERFORMANCE. THE SOLE AND EXCLUSIVE REMEDY FOR BREACH OF WARRANTY HEREUNDER SHALL BE LIMITED TO
REPAIR, CORRECTION, REPLACEMENT, OR REFUND OF PURCHASE PRICE UNDER THE LIMITED WARRANTY CLAUSE IN
SECTION 1 HEREIN. IN NO EVENT, REGARDLESS OF THE FORM OF THE CLAIM OR CAUSE OF ACTION (WHETHER BASED
IN CONTRACT, INFRINGEMENT, NEGLIGENCE, STRICT LIABILITY, OTHER TORT OR OTHERWISE), SHALL SELLER'S
LIABILITY TO BUYER AND/OR ITS CUSTOMERS EXCEED THE PRICE TO BUYER OF THE SPECIFIC GOODS
MANUFACTURED OR SERVICES PROVIDED BY SELLER GIVING RISE TO THE CLAIM OR CAUSE OF ACTION. BUYER
AGREES THAT IN NO EVENT SHALL SELLER'S LIABILITY TO BUYER AND/OR ITS CUSTOMERS EXTEND TO INCLUDE
INCIDENTAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES. THE TERM “CONSEQUENTIAL DAMAGES” SHALL INCLUDE,
BUT NOT BE LIMITED TO, LOSS OF ANTICIPATED PROFITS, LOSS OF USE, LOSS OF REVENUE, AND COST OF CAPITAL.

Introduction

Table of Contents

Table of Contents

1 Introduction .......................................................................... 1

1.1 Theory of operation ........................................................................................................2

1.2 Equipment description ...................................................................................................4

1.2.1

Model 700XA FPD ...............................................................................................6

1.2.2

Model 700XA FPD front entry .............................................................................7

1.2.3

Model 1500XA FPD .............................................................................................8

1.3 Glossary .........................................................................................................................9

2 Setup ................................................................................... 11

2.1 Gas connections .......................................................................................................... 11

2.2 Environmental Considerations ..................................................................................... 11

2.3 Utility gases ................................................................................................................. 11

2.4 Venting ....................................................................................................................... 12

3 Operation and maintenance.................................................. 15

3.1 Operation .................................................................................................................... 15

3.1.1

Igniting the flame manually ............................................................................. 16

3.2 Maintenance ............................................................................................................... 17

3.3 Troubleshooting.......................................................................................................... 18

A Appendix A: Drawings .......................................................... 21

A.1 Enclosure threaded entry details ................................................................................. 21

B Appendix B: Manufacturer’s manuals ..................................... 27

B.1 Flame Photometric Detector Operation Manual ........................................................... 28

B.2 GUB FPD 118500-3411 GUB ........................................................................................ 37

C Appendix C: Spare Parts List .................................................. 79

i

Figure

1 Introduction

The flame photometric detector (FPD) that you have received is factory-engineered to be used in
conjunction with all Rosemount gas chromatographs. The FPD can be used as a solitary detector to
measure low levels of sulfur compounds in natural gas or as a secondary detector in conjunction
with a thermal conductivity detector (TCD) that allows the GC to analyze the full range of
components present in a natural gas sample, including sulfur compounds.

1-1: Flame Photometric Detector (FPD)

Introduction

A. Flame photometric detector (FPD)
B. Photomultiplier tube
C. Flame cell
D. Electrometer board

An FPD (A) typically consists of the following major components:

The flame cell (C) - Located in the lower enclosure, the flame cell has connections for fuel gas,
hydrocarbon-free air, sample injection (process gas plus nitrogen carrier), and an exhaust pipe. It is
fitted with an RTD to monitor the temperature when running, and an ignitor to light the fuel gas.

The photomultiplier tube (B) - Located in the lower enclosure, the photomultiplier tube contains the
sensors that measure the light that is emitted from the flame cell during operation. It has one signal
lead and one high voltage wire that take the signal from the detector to the electrometer board
and provide the power for ignition. The leads are co-axial type cables.

1

Introduction

The electrometer board (D) - Located in the upper enclosure, the electrometer board amplifies and
processes the signal data from the detector, and sends it to the CPU board on the GC. It also
provides the ignition circuit, controls the re-light function, and generates the flame out alarm.

1.1 Theory of operation

NOTICE

See also Section 1.3 of this manual, for definitions of some of the terminology used in the following
explanations.

The detection system in the FPD uses the reactions of sulfur components in a hydrogen or air flame
as a source for analytical detection. The source of the FPD's signal is derived from the light
produced by an excited molecule created in the flame's combustion, which is a photochemical
process called chemiluminescence.

A thermocouple is fitted to the flame cell to ensure that the flame is present. If the flame is not
detected, the electrometer shuts off the hydrogen to the flame cell. It then supplies a voltage to
the igniter, waits five seconds and opens the hydrogen shut off valve. The electrometer will make
ten ignition attempts if necessary. If it is not successful, then the hydrogen is shut off, an alarm is
triggered on the GC and the unit awaits attention from the operator.

NOTICE

To ignite the flame manually, see Section 3.1.1.

The signal is sent from the PMT to the electrometer to be amplified. The electrometer also provides
the PMT with the high voltage it requires to operate the auto re-light circuits.1.3

2

Introduction

Figure

1-2: Elution of Components

1.

2.

3.

4.

5.

Carrier gas only at the detector

First component begins to elute from the columns and is sensed by the detector.

Peak concentration of first component.

The second component begins to elute from the columns and is sensed by the detector.

Peak concentration of the second component.

3

Introduction

The signal is then sent to the preamplifier board for further amplification. In addition, the
preamplifier converts each voltage signal to a value that is proportional to the concentration of the
component detected in the gas sample. The preamplifier provides four different gain channels as well
as compensation for baseline drift. The signals are sent to the GC for computation or for viewing on
a PC monitor or local operator interface (LOI).

While the GC is in Idle mode, prior to injecting a sample, the detector is exposed to pure carrier gas.
In this condition, the output from the detector is electrically nulled. The detector output is set to 1
mV DC. This is measured on the red and black terminals on the preamplifier board, and adjusted
using the potentiometer (R38) on the electrometer PCB.

1.2 Equipment description

FPDs are available in the following configurations:

• 700XA FPD

• 700XA FPD Front Entry

• 1500XA FPD

NOTICE

The Front Entry configurations include an additional frame to allow all the FPD enclosures to be
mounted on the front of the unit. This allows the unit to be located close to a wall because no rear
access is required for installation or maintenance.

All configurations are ATEX-certified. The differences between the configurations are detailed in
later sections of this chapter.

4

Introduction

The FPD used with the Model 500, 700, and 700XA gas chromatographs has the following
hazardous area certification markings:

5

Introduction

Figure

1.2.1

Model 700XA FPD

1-3: Model 700XA FPD

The Model 700XA FPD consists of four explosion-proof enclosures mounted on a frame plus an
explosion-proof solenoid valve that acts as a hydrogen shut-off valve.

6

Introduction

Figure

The enclosures contain the following components:

• Electrometer assembly

• Flame cell and photometric detector tube

• Transformer, either a 230/110 Vac or a 110/110 Vac

• PID temperature controller and relay

• Hydrogen shut-off valve

Place the FPD as close as possible to its partner GC to minimize the length of sample tubing
between them, and keep the cycle time as short as possible.

The tubing size required to operate the FPD flame cell is 1/16 in. OD 0.010 in. ID. All tubing enters
the flame cell’s enclosure through a specially designed tubing gland. All internal fittings are
Swagelok double ferrule compression fittings.

1-4: Specialized Tubing Gland

1.2.2

Model 700XA FPD front entry

The Model 700XA FPD front entry is comprised of the same components as the standard Model
700XA FPD with an additional frame added to allow all the enclosures to be mounted on the front
of the unit. This allows the unit to be located close to a wall, because no rear access is required for
installation or maintenance.

7

Introduction

Figure

1.2.3

Model 1500XA FPD

1-5: Model 1500XA FPD

The Model 1500XA FPD consists of four explosion-proof enclosures mounted on a frame plus an
explosion-proof solenoid valve that acts as a hydrogen shut-off valve. The enclosures contain the
following components:

• Electrometer assembly

• Flame cell and photometric detector tube

• Transformer, either a 230/110 Vac or a 110/110 Vac

• PID temperature controller and relay

• Hydrogen shut-off valve

8

Introduction

Figure

Place the FPD as close as possible to its partner GC in order to minimize the length of sample tubing
between them, and therefore to keep the cycle time as short as possible.

The tubing size required to operate the FPD flame cell is 1/16 in. OD 0.010 in. ID. All tubing enters
the flame cell’s enclosure through a specially designed tubing gland. All internal fittings are
Swagelok double ferrule compression fittings.

1-6: Specialized Tubing Gland

1.3 Glossary

Auto Zero

Automatic zeroing of the preamplifier. May be entered into the controller to take place at any time
during the analysis when either the component is not eluting or the baseline is steady (not
normally used).

Chromatogram

A permanent record of the detector output. A chromatograph is obtained from a PC interfaced with
the detector output through the GC controller. A typical chromatogram displays all component peaks
and gain changes. It may be viewed in color as it is processed on a PC VGA display. Tick marks
recorded on the chromatogram by the GC Controller indicate where timed events take place.

Component

Any one of several different gases that may appear in a sample mixture. For example, sample gas
usually contains the following components: ethyl mercaptan, t-butyl mercaptan, methyl ethyl
sulphide, diethyl sulphide, hydrogen sulphide, and carbonyl sulphide.

9

Introduction

Response Factor

Correction factor for each component as determined by the calibration. It is defined by the
equation:

where

= Area response factor for component n in area per mole percent (%)

ARF

n

= Height response factor for component n

HRF

n

= Area associated with component n in calibration gas

Area

n

= Height associated with component n in mole % in calibration gas

Ht

n

= Amount of component n in mole % in calibration gas

Cal

n

Retention time

The time in seconds that elapses between the start of analysis ( 0 seconds) and the sensing of the
maximum concentration of each component by the analyser detector.

10

2 Setup

2.1 Gas connections

Use Silcosteel® or equivalent tubing for all calibration gas and process gas connections on all FPDs
that are used to measure low range sulfur components. If you use Grade 316 or other stainless steel
piping, the sulfur components will adhere to the internal surface of the pipe, and will continue to
do so until the entire internal surface of the tubing is coated or conditioned, which will result in
lower than expected levels of sulfur components reaching the detector for measurement.
Conditioning may take one week or longer, depending on the levels of sulfur components and the
length of the tubing.

2.2 Environmental Considerations

FPDs are sensitive to changes in temperature and pressure; therefore, place them in shelters that
have stable temperature and pressure. Do not use positive pressurization for shelters.

2.3 Utility gases

FPDs require the following utility gases:

• Hydrogen - 99.995% purity

Setup

• Hydrocarbon-free air

• Nitrogen - 99.995% purity (carrier gas)

• Helium - 99.995% purity (optional second carrier gas)

11

Setup

Figure

Make all utility and process gas connections with Swagelok
fittings. Metric conversion kits are available; contact your Rosemount sales representative for more
information.

These are typical values supplied for information only. Actual values are application specific.

2-1: Typical Pressure and Flow Rate Information

2.4 Venting

All Rosemount FPD modules have a vent from the flame cell that exits the GUB enclosure via a
proprietary Exd breather/drain/ flame arrestor assembly. The exhaust from the flame cell emits
water vapor as a result of burning hydrogen as fuel. This vapor condenses in the exhaust tubing
outside the GUB enclosure, and can be seen as drips of water.

®

1/8-inch double ferrule compression

Vent the FPD exhaust to atmosphere. Do not subject the vent to any back pressure because this will
have a detrimental effect on the detector, and may cause the flame to extinguish.

12

Setup

WARNING

Hydrogen-air mixtures can ignite with very low energy input. For reference, an invisible spark or a
static spark from a person can cause ignition. Although the auto- ignition temperature of hydrogen
is higher than those for most hydrocarbons, hydrogen's lower ignition energy makes the ignition of
hydrogen–air mixtures more likely.

Use a container with the FPD module to collect the condensed water from the FPD vent. Do not
pipe the vent away unless you can guarantee a continuous downward slope on the pipe and no
back pressure or obstruction by water.

13

Setup

14

3 Operation and maintenance

3.1 Operation

The FPD operates as a separate detector. It is controlled by and reports to the GC. The flow rates for
the utility gases and the carrier gas are factory set, and are specific to each FPD. These should only
be adjusted by fully trained and authorized personnel.

The FPD is identified as Detector #1 on the Detector screen, which is viewable with MON2000,
MON2020, and the LOI. When used in conjunction with a TCD, the FPD is Detector #1, and the TCD
is Detector #2.

NOTICE

The electrometer switch (A), which has three positions—up for Reset, centered for Normal, and
down for Override—should not be left in Override.

Operation and maintenance

A. Electrometer switch

3 - 1

15

Operation and maintenance

3.1.1

Igniting the flame manually

1.

Connect air to the inlet and slowly bring the inlet pressure to 60 psig.

2.

Connect hydrogen to the inlet and slowly bring the inlet pressure to 60 psig.

3.

Remove tubing from flame cell exhaust and use a digital flow meter to adjust the air control
valve until a reading of 160 cc/ min is obtained.

4.

Turn off the air supply.

5.

Set the auto relight switch (S1) on the electrometer PCB to the OVERRIDE position.

6.

Use the digital flow meter to adjust the hydrogen control valve until a reading of 100
cc/min is obtained.

7.

Turn on the air supply.

8.

Set the auto relight switch (S1) on the electrometer PCB to the RUN position. The auto
relight sequence starts as follows:

a. The LED on the electrometer comes on after 10 seconds, and the glow plug fitted to the

side of the flame cell is now supplied a voltage.

b. After another 5 seconds, the hydrogen shut off valve operates.
c. The gas mixture is ignited.
d. If the flame does not light in 5 seconds, the electrometer de-energizes the hydrogen

shut off valve to stop the flow into the flame cell.

e. The flame cell is then purged with air and nitrogen carrier.
f. The process starts again—up to 10 times—until the flame stays lit.

16

g. If the flame does not stay lit, the LED flashes. If the alarm output is linked to the 2350A

controller discreet input, there will be an alarm present on the controller.

h. Set the auto relight switch (S1) on the electrometer PCB to the RESET position and then back

to the RUN position. The re-light sequence is restarted.

If the unit still fails to light after resetting the electrometer, recheck the air and hydrogen flows.

3.2 Maintenance

The FPD is a complex piece of equipment and needs to be regularly maintained, preferably as part
of an annual planned maintenance process.

The following important maintenance procedures should be conducted on an annual basis:

• Replace the flame cell and photometric tube O-rings, except for the Kalrez O-ring, which

should be replaced every 24 months.

CAUTION

Be certain that the flame cell has cooled down before touching it, because it often reaches a
temperature of 170 °C (338 °F).

Operation and maintenance

• Lubricate the stem of the hydrogen shut-off valve.

For both of these operations, the GC should be shut down, and the appropriate permits and
permissions gained before commencing.

Only trained and authorized personnel should carry out maintenance..

NOTICE

The flame out logic should always be tested to ensure it works at the end of any maintenance.

Failure to maintain the FPD may cause a loss of functionality and can result in permanent damage to
the equipment.

17

Operation and maintenance

Fault symptom(s)

Possible solution(s)

When monitoring the baseline

• Check high voltage is present on coax.

Upsets are being seen, but there

• Check the 12 V GND wiring to the electrometer board. The two GND terminals on

3.3 Troubleshooting

Only competent trained personnel should troubleshoot FPDs.

The following list of faults is not definitive. It only details the most common faults.

in MON2020, there are no
upsets present when the auto
re- light circuit fires.

If no voltage, remove coax
connector.

If voltage is present, check
signal coax.

are no peaks when gas is
injected.

• Approx. -600 Vdc

• If voltage now present on board, check coax cable.

• Check BNC coax connectors are tight.

• If there is no voltage, or the signal cable is OK, replace electrometer.

connector #2 are not linked on board. If there are three black wires, ensure that pins 1
and 4 are connected to the power supply. The other wire is for the flame cell GND.

• Check the tubing going into the bottom of the flame cell. Loosen fitting and pull

tubing downwards while watching CGM.

• If peaks appear, then the tubing needs to be cut.

• Check to see if there is flow from the metering valve next to the heater block.

• Check the sample is getting to the flame cell.

• Try replacing the columns one at a time.

• Check you are getting carrier through port 1 with valve 2 on and through port 5 with

valve 2 off. If not check the vents on the Alcon valve for back pressure.

18

Operation and maintenance

Fault symptom(s)

Possible solution(s)

Air and H2 flows are set

• Using a digital thermometer connected to the thermocouple wires

Unit give good size sample

There might be soot on the sample tube going to the flame-cell. Pull tube down

Flame cell temperature cannot

Check the flame cell thermistor.

Flame cell temperature is

• Check that the thermistor has not been pushed right through the flame

Unable to balance the bridge.

• Check the BNC connectors for the signal in and the high voltage. Ensure

Restrictor metering valve seems

restricting the output flow

®

Peaks are very small or appear

• Check nitrogen flow into union at flame cell.

correctly, and the unit fails to
stay lit.

peaks; then after a while, the
peaks are not present, but the
relight still gives good peaks.

be controlled.

erratic.

coming from the bottom of the flame-cell, check that the temperature is
160 °C (320 °F).

• Check flame out thermocouple wires.

• Ensure no insulation is trapped under screw on terminal strip.

• Try pulling the sample tube out when it is attempting to light in case the

tube is affecting the fuel mixture.

• Replace the flame cell and try again.

• Ensure that the signal wires are connected to the correct place;

remember that the white signal wire should be connected to the TC+ of
the CON5.

slightly while watching the CGM to see if that cures the fault.

The resistance is approximately 100 KΩ at ambient. Resistance goes down as

temperature goes up.

cell.

• In later models, the flame cell will be blanked at end of holes to ensure

that this cannot happen.

• Check there is enough heat-sink compound fitted around sensors.

that they are tight.

• Cut off the flame and check the response from the detector on a live

CGM.

• Try changing the filter.

to be
completely.

to be back to front.

• Apply Snoop

• Change the metering valve.

• This should be no less than 15cc/min.

to the two fittings at the bottom of the metering valve.

19

Operation and maintenance

Fault symptom(s)

Possible solution(s)

Noisy baseline and/or very big

Check the air supply, which should be no lower than 500psi in the cylinder.

dips on the baseline.

20