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Safety control systems conference 2015 - Introduction to functional safety in gas detection (Preeju)

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Objective of the Presentation is to create awareness on
1. The functional safety standards 60079-29-3 which applicable for fire & gas detection to end-users.
2. Why gas detection should not be clubbed together with Process Control Standard IEC 61511 and the various standards applicable.
3. Gas dispersion & placement of Gas detectors & role of gas detectors in risk reduction.
4. Technologies used in Flame & gas detection

Topics Covered:-
1 Gas Dispersion & Sensor Placement
2 Principle of Operation – F&G System
3 Risk reduction & Role of F&G detectors
4 Functional Safety Standards for F&G and Projects.
5 Decision Making on Type Of F&G System
6 Applications of F&G Detectors
7 Why Using PLC's may generate trouble?

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Safety control systems conference 2015 - Introduction to functional safety in gas detection (Preeju)

  1. 1. Introduction to Functional Safety Standard for Gas Detection Preeju Anirudhan (Instr. & Elec. Eng.) Product & Application Manager – Fire & Gas Detection Solutions Marketing Manager – Chemical, Oil & Gas Draeger Safety Pacific Pty. Ltd. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  2. 2. Functional Safety – Fire and Gas Detection Systems Objectives Create awareness on –The functional safety standards 60079-29-3 which applicable for fire & gas detection to end-users. –Why gas detection should not be clubbed together with Process Control Standard IEC 61511 and the various standards applicable. –Gas dispersion & placement of Gas detectors & role of gas detectors in risk reduction. –Technologies used in Flame & gas detection Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  3. 3. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  4. 4. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  5. 5. Gas heavier than air: dense gas Gas lighter than air: buoyant gas Functional Safety – Fire and Gas Detection Systems Gas dispersion & Gas categories Hydrogen Methane Ammonia Acetylene Nitrogen Oxygen Carbon dioxide Propane Chlorine Benzene Phosgene Gas behaving like liquids liquefied gas Gas behave unpredictably gas jet elevated release Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  6. 6. Different scenarios which are typical for gas leaks within a building Functional Safety – Fire and Gas Detection Systems Gas dispersion in closed Rooms Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  7. 7. Different scenarios which are typical for gas leaks within a building Functional Safety – Fire and Gas Detection Systems Gas dispersion in closed Rooms Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  8. 8. Functional Safety – Fire and Gas Detection Systems Gas Dispersion Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  9. 9. • The correct installation of gas sensors for the gas detection in outdoor areas is extremely important. • Determining “what is to be protected” is important, i.e. people, process, asset and visualising the possible impact in the event of a gas leak/explosion. • Environmental conditions can have a detrimental impact on the efficiency of the gas detection systems if care is not taken during the installation process. • Sensors must be protected from weather conditions, e.g. heavy rains can splash more than 30Cm off the ground, so it makes sense for sensors to be placed above 30Cm when detecting heavy gases. • Gas sensors should also be located downstream of prevailing winds; also consider the wind effects caused by buildings, tanks and other obstructions. Areas where wind changes directions during seasons will also need to be considered. • Access to the detectors must be considered for ease of maintenance and use of remote sensors, remote calibration adaptors, remote display, remote bump-test adapter must be considered. Functional Safety – Fire and Gas Detection Systems Placement of Gas detectors – Outdoor Environment Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  10. 10. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  11. 11. 12 Functional Safety – Fire and Gas Detection Systems Gas & Flame Detection Methods & Principles of Operation Gas •Infra red: Point & Open Path •Catalytic: Point •Electro-chemical: Point for Toxic gases & Oxygen •Laser: Open Path for Ammonia, H2S & CO2 •PID: Point for VOC •MOS: Point for H2S –low humidity applications •IMS: Point for warfare gases •Paramagnetic: Oxygen (low/high) •Acoustic: for high pressure leaks (Ultrasonic) Flame •UV •IR •Triple IR •UV-IR •Visual Flame (CCTV Flame) Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  12. 12. FLAMEPROOF ENCLOSURE MEASURING DETECTOR REFERENCE DETECTOR BEAM SPLITTER IR-SOURCES SAPPHIRE WINDOW GAS HEATED REFLECTOR C H 4 IR SOURCE GAS CUVETTE OPTICAL FILTER Hydrocarbons absorb Infra-red light if present in the measuring area. The difference between the reference & signal is proportional to the amount of hydrocarbon or other gases present. Functional Safety – Fire and Gas Detection Systems Principles of Operation of Infra-Red Point-Gas Detectors Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  13. 13. Functional Safety – Fire and Gas Detection Systems Principles of Operation of Open Path Detectors (Flammable & Toxic) Transmitter Receiver An infrared/Laser beam (2 wavelengths) sent from TX to RX Reference wavelength Signal wavelength Gas will absorb only the signal wavelength Signal wavelength absorbed C HH HH Reference wavelength unaffected Receiver outputs a gas reading Pulsar 1 Pulsar 2Pulsar Duct Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  14. 14. Functional Safety – Fire and Gas Detection Systems Principles of Operation of Catalytic Sensors Wheatstone bridge uBridge Rth R2 R1Rref HEAT Oxidation leads to energy release The resulting heat is proportional to the amount of reactions per time Temperature increase can be measured as resistance change of an embedded platinum coil and is proportional to the flammable gas concentration. The resulting heat leads to a temperature increase ∆T The resulting heat is proportional to the amount of flammable gas molecules Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  15. 15. Electrochemical Sensors Principle A chemical reaction of the target gas with the electrolyte produces electrons (current) which is proportional to the gas concentration. Why? Electrochemical sensors are very specific in general to the target gases and measure gases or vapours of very low concentration of gases that are difficult to measure using catalytic or Infra red type gas detectors. Very low levels alarms to comply with exposures Functional Safety – Fire and Gas Detection Systems Principles of Operation of Electro-Chemical sensors Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  16. 16. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  17. 17. risk Risk – ignition from non-Ex rated equipmentdangerous safe necessary risk reduction actual risk reduction tolerable risk Functional Safety – Fire and Gas Detection Systems Risk reduction & role of Fire & Gas detection. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  18. 18. risk Risk – ignition from non-Ex rated equipmentdangerous safe Air inlet positioning Ventilation rate emergency shut- down Gas Detection residual risk risk reduction necessary risk reduction actual risk reduction tolerable risk Functional Safety – Fire and Gas Detection Systems Risk reduction & role of Fire & Gas detection. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  19. 19. risk Risk – ignition from non-Ex rated equipmentdangerous safe Air inlet positioning Ventilation rate emergency shut- down Gas Detection residual risk risk reduction necessary risk reduction actual risk reduction tolerable risk Functional Safety – Fire and Gas Detection Systems Risk reduction & role of Fire & Gas detection. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  20. 20. risk dangerous safe Gas Detection residual risk Risk – ignition from non-Ex rated equipment risk reduction necessary risk reductionactual risk reduction tolerable risk Functional Safety – Fire and Gas Detection Systems Risk reduction & role of Fire & Gas detection. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  21. 21. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  22. 22. Functional Safety – Fire and Gas Detection Systems What IEC 61508 Standards says The scope of IEC 61508 ( Part-1,Clause 1.1) …….A major objective of this standard is to facilitate the development of application sector international standards by the technical committees responsible for the application sector. This will allow all the relevant factors, associated with the application, to be fully taken into account and thereby meet the specific needs of the application sector. ………. Old Edition and NEW Edition Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  23. 23. Functional Safety – Fire and Gas Detection Systems Functional Safety Standards & where gas detection fits Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  24. 24. Functional Safety – Fire and Gas Detection Systems Gas Detection Standards - Explained EN 50402 : 2005 (2013) IEC 60079-29-3 A Product based standard for the Manufacturers A life cycle approach for the system designer, engineering contractor, installation, start-up, service, modification and decommissioning Includes some good guidance of the special requirements in the world of Gas Detection An entire Clause describing the special requirements of gas detection Mandates the need for a R&D facility to operate under a functional safety management system Mandates the need for everyone involved with the life cycle to operate under a functional safety management system Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  25. 25. Functional Safety – Fire and Gas Detection Systems Various Standards for Fire & Gas Detection Systems EN 60079 – 10 -1:2009 (EN 1127-1 : 2011)EN 60079 – 10 -1:2009 (EN 1127-1 : 2011) ISO 31000 : 2009ISO 31000 : 2009 BS 6079 -1 : 2010BS 6079 -1 : 2010 EN 60079 – 1 : 2007EN 60079 – 1 : 2007 IEC 60079 – 29 – 1 : 2007 IEC 61508 : 2011IEC 61508 : 2011 EN 60079 – 19 : 2011EN 60079 – 19 : 2011 • Standards for specifying the hazardous locations • Standards for Risk Analysis • Standards for Project Management • Standards for Product design with respect to Ex areas • Standards for Product performance • Standards for Product Integrity and associated QA systems • Standards for repair workshops Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  26. 26. Functional Safety – Fire and Gas Detection Systems Explosive atmospheres – 60079 Part 29-3: Guidance on functional safety of fixed gas detection systems – This International standard gives guidance for the design and implementation of a fixed gas detection system, including associated and/or peripheral gas detection equipment, for the detection of flammable gases/vapours and Oxygen when used in a safety-related application in accordance with IEC 61508 and IEC 61511. This International standard also applies to the detection of toxic gases. Other parts of this international standard and pertinent local, national and international standards separately specify the performance requirements of a gas detector and a gas detection control unit (logic solver). These standards are commonly known as Metrological Standards and are concerned with the accuracy of the measured value, the overall system performance, but not the device or system integrity with respect to the safety function. This international standard applies to the integrity of the safety function. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  27. 27. Functional Safety – Fire and Gas Detection Systems Standards currently applied in Projects Project Products developed under IEC 61508 Application standards written within the framework of IEC 61508 Machinery safety delivered under IEC 62061 Process safety delivered under IEC 61511 ANSI/ISA 84.00.01 Fire and Gas Detection Systems Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  28. 28. Functional Safety – Fire and Gas Detection Systems Standards that shall be followed in Projects Project Products developed under IEC 61508 Application standards written within the framework of IEC 61508 Machinery safety delivered under IEC 62061 Gas Detection delivered under BS EN 50402 / IEC 60079-29-3 ANSI/ISA 84.00.07 Fire & Gas Process safety delivered under IEC 61511 ANSI/ISA 84.00.01 Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  29. 29. Functional Safety – Fire and Gas Detection Systems Interpretation of Standards General Understanding Actual Requirement A Fire & Gas control circuit includes a detector, a control card and an output device A Fire & Gas control loop includes performance approved detectors, performance approved control cards and output devices The wiring diagram and the Cause & Effects chart are identical The Ex zoning and the use of Intrinsically Safe isolators does not change The Control System is programmed using competent engineers using Ladder Logic Programming is not allowed (Competency would show that programming is not allowed and performance approved equipment is a pre-requisite) Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  30. 30. Functional Safety – Fire and Gas Detection Systems Importance of Performance Approvals What needs performance approval? Why need performance approval? Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  31. 31. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  32. 32. Functional Safety – Fire and Gas Detection Systems Decision path - Types of Fire and Gas detection system Is there a stated Safety function & Safety integrity? Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  33. 33. The definition of a Standard Fire and Gas detection system is – A system who’s specification does not detail a contribution to ‘risk reduction’ – A system which alarms only, with no supporting operational measures which are announced as ‘risk reduction’ – A system which is not guarded against modifications – A system which has no mandatory service and proof test intervals – A system which is not supported by a fixed spare parts list for inspection, maintenance and repair Functional Safety – Fire and Gas Detection Systems Standard Fire and Gas detection system Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  34. 34. Functional Safety – Fire and Gas Detection Systems F&G Classification – Protection, Mitigation or Safeguarding system The definition of a Fire and Gas detection system having a Protection function • A Protection system reduces the frequency of the hazard The definition of a Fire and Gas detection system having a Mitigation function • A Mitigation system reduces the consequence of the hazard The definition of a Fire and Gas Safeguarding system is • An additional system which operates in parallel to the SIS Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  35. 35. The definition of a Fire and Gas detection system having a ‘function of safety (safety requirement specification) – A system who’s specification includes a contribution to ‘risk reduction’ • Safety Integrity level – A system which alarms only, but is supported by operational measures which are announced as ‘risk reduction’ • Safety Integrity level and Operational procedures – A system which is fully supported by a service regime, proof test interval and supporting documentation for spare parts interchangeability – A system which is guarded against unauthorised modification – A system who’s life cycle is supported by a Functional Safety Management system Functional Safety – Fire and Gas Detection Systems Safety Function - Fire and Gas detection system Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  36. 36. • The speed of response of the sensing element (proof test) • Alarm philosophy • The trip level for a specific measuring point • The action required behind the trip point • The time taken for the action to be complete • The required integrity of the complete safety function • The operational procedures • Environmental conditions Note : sensor coverage or mitigation effectiveness is not part of the safety function Functional Safety – Fire and Gas Detection Systems Criteria of a Safety Function Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  37. 37. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  38. 38. Functional Safety – Fire and Gas Detection Systems Applications using gas detectors. Detection of Hydrocarbons (oil & gas/Chemical/manufacturing) Detection in 0 – 100% LEL Leak Detection (Analyzer rooms/labs/solvent storage) Detection in PPM /0 – 10% LEL Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  39. 39. Functional Safety – Fire and Gas Detection Systems Applications for monitoring Flammable gases at heights Special attention must be paid when installing gas detector at heights. E.g. •At entrance of air intake ducts. •Inside air intake ducts •Under ceiling or roof space at heights for CH4 detection in storage facilities & turbine rooms. •Cost of maintenance (scaffolding/ cherry picker/height safety permits) Solutions:- Select performance detectors which has remote test/maintenance/calibration features, so basic maintenance can be performed without direct access to the sensor. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  40. 40. Functional Safety – Fire and Gas Detection Systems Applications for monitoring Flammable gases at Depths (confined Space) Special attention must be paid when installing gas detector at depths or confined spaces. E.g. •In confined spaces (sumps) •Drains /Well heads/collection points •Tank Bund walls subject to flooding. •Cost of replacement due to water damage, CSE extra permits) Solutions:- Select performance approved detectors which has remote test/maintenance/ calibration features, so basic maintenance can be performed without direct access to the sensor. Ensure the sensors are suitable for the application and can withstand flooding/submersion (IP 67/68) Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  41. 41. Functional Safety – Fire and Gas Detection Systems Applications – inline monitoring When designing Sampling systems, consider the following •Delay for gas transit •Ensure proper flow for reliable gas reading. •Ex-Approvals all the equipment used in the system. •Calibration of gas sensors inline. •Easy access for maintenance (cleaning/replacements) •Process conditions (heat/ humidity/ temperature/ Pressure /corrosion) •Sample Conditioning as required. Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  42. 42. 1 Gas Dispersion & Sensor Placement 2 Principle of Operation – F&G System 3 Risk reduction & Role of F&G detectors 4 Functional Safety Standards for F&G and Projects. 5 Decision Making on Type Of F&G System 6 Applications of F&G Detectors 7 Why Using PLC's may generate trouble? Functional Safety – Fire and Gas Detection Systems AGENDA Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  43. 43. – SAFETY may be compromised because the programming is open to the programmer. Plant operations may be affected due to false alarms. – Analogue input channels need to be configured correctly to recognise the Special signals of Fire & Gas detection transmitter (0 – 4mA & 20 – 22mA) – PLC’s are not designed for gas detection applications with respect to the International Standards for gas detection systems – PLC’s does not have local displays to indicate gas readings – only external viewing panels are available which require configuration – Gas detection system manufacturer has no control on PLC quality, availability, obsolescence, pricing etc. – Skilled engineers are not always available and our tech support do not support PLC based central control systems Functional Safety – Fire and Gas Detection Systems Why using a PLC can generate trouble? Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
  44. 44. Functional Safety – Fire and Gas Detection Systems Thank you Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas Email: Preeju.Anirudhan@Draeger.com

Editor's Notes

  • The Objective was the basis on which standards were developed for the Fire & Gas detection system. Fire & Gas deetction system have unique requirements which differ from other equipment & standards.
    e.g.
    Need for diagnostic signals & additional information below 4mA and above 20mA
    Built in fault tolerance due to short circuit using a rate a rise algorithm (fault should not cause a flase gas alarm)
    Performance approvals for the gas detector to detect the target gas in a functional safety application.
  • Gases and vapors can be sorted by their specific weight or density. This is why you need to select the correct type of gas detector and determine the correct placement. If a gas is buoyant and the dispersion is not disturbed, it will rise into the air. If a gas belongs to the group of dense gases it will move towards the ground. As always in life there are exception to be considered, behaving the opposite way. If temperature or pressure is involved substances might show different behavior, at least for a period of time until they equilibrate with the environmental conditions. If liquefied substances leak they might first form a puddle which evaporates over time. Leaking Gas jets can point in all direction and show no specific behavior.
  • List of gases heavier than air. These gases tend to stay on the ground for a long time and travel downhill and behaves similar to liquids..
  • An electrochemical Sensor is comparable to a battery which generates some µWatt of power if the target gas is present.
    EC sensor is supposed to be:
    reactive to a defined target gas
    sensitive to very low concentrations
    generate a concentration dependant signal
    fast in response
    measure accurately over a long period
    function for a long time
    A sensor should not be:
    disturbed by environmental parameters
    cross-sensitive to other substances around
    an environmental hazard
  • Reference from the standard
  • The application of standards should be as mentioned for each part of the project.
  • e.g. for continuous mode Safety function: Continuous flow dryer
  • RISK [expected loss/time] = PROBABILITY [undesirable event/time] x CONSEQUENCE [expected loss/undesirable event
  • ×