safety control systems conference 2015 - introduction to functional safety in gas detection (preeju)
TRANSCRIPT
Introduction to Functional Safety Standard for Gas Detection
Preeju Anirudhan (Instr. & Elec. Eng.)Product & Application Manager – Fire & Gas Detection SolutionsMarketing Manager – Chemical, Oil & Gas
Draeger Safety Pacific Pty. Ltd.
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
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
1 Gas Dispersion & Sensor Placement2 Principle of Operation – F&G System
3 Risk reduction & Role of F&G detectors4 Functional Safety Standards for F&G and Projects.5 Decision Making on Type Of F&G System
6 Applications of F&G Detectors7 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
1 Gas Dispersion & Sensor Placement2 Principle of Operation – F&G System3 Risk reduction & Role of F&G detectors
4 Functional Safety Standards for F&G and Projects.5 Decision Making on Type Of F&G System6 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
Gas heavier than air:dense gas
Gas lighter than air:buoyant gas
Functional Safety – Fire and Gas Detection Systems Gas dispersion & Gas categories
HydrogenMethaneAmmoniaAcetyleneNitrogen
OxygenCarbon dioxidePropaneChlorineBenzenePhosgene
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
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
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
Functional Safety – Fire and Gas Detection Systems Gas Dispersion
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
• 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
1 Gas Dispersion & Sensor Placement2 Principle of Operation – F&G System3 Risk reduction & Role of F&G detectors4 Functional Safety Standards for F&G and Projects.5 Decision Making on Type Of F&G System
6 Applications of F&G Detectors7 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
12
Functional Safety – Fire and Gas Detection SystemsGas & 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
FLAMEPROOF ENCLOSURE
MEASURING DETECTOR REFERENCE DETECTOR
BEAM SPLITTER
IR-SOURCES SAPPHIRE WINDOW
GASHEATED REFLECTOR
CH4
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 SystemsPrinciples of Operation of Infra-Red Point-Gas Detectors
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
Functional Safety – Fire and Gas Detection SystemsPrinciples of Operation of Open Path Detectors (Flammable & Toxic)
Transmitter Receiver
An infrared/Laser beam (2 wavelengths) sent from TX to RXReference 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
Functional Safety – Fire and Gas Detection SystemsPrinciples 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
Electrochemical SensorsPrincipleA 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 SystemsPrinciples of Operation of Electro-Chemical sensors
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
1 Gas Dispersion & Sensor Placement2 Principle of Operation – F&G System3 Risk reduction & Role of F&G detectors4 Functional Safety Standards for F&G and Projects.5 Decision Making on Type Of F&G System6 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
risk
Risk – ignition from non-Ex rated equipmentdangerous
safe
necessaryrisk reduction
actual risk reduction
tolerable risk
Functional Safety – Fire and Gas Detection SystemsRisk reduction & role of Fire & Gas detection.
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
risk
Risk – ignition from non-Ex rated equipmentdangerous
safe
Air inlet positioning
Ventilation rate
emergency shut-down
Gas Detection
residual risk
riskreduction
necessaryrisk reduction
actual risk reduction
tolerable risk
Functional Safety – Fire and Gas Detection SystemsRisk reduction & role of Fire & Gas detection.
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
risk
Risk – ignition from non-Ex rated equipmentdangerous
safe
Air inlet positioning
Ventilation rate
emergency shut-down
Gas Detection
residual risk
riskreduction
necessaryrisk reduction
actual risk reduction
tolerable risk
Functional Safety – Fire and Gas Detection SystemsRisk reduction & role of Fire & Gas detection.
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
risk
dangerous
safe
Gas Detection
residual risk
Risk – ignition from non-Ex rated equipment
riskreduction
necessaryrisk reductionactual risk
reduction
tolerable risk
Functional Safety – Fire and Gas Detection SystemsRisk reduction & role of Fire & Gas detection.
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
1 Gas Dispersion & Sensor Placement2 Principle of Operation – F&G System3 Risk reduction & Role of F&G detectors
4 Functional Safety Standards for F&G and Projects.5 Decision Making on Type Of F&G System6 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
Functional Safety – Fire and Gas Detection SystemsWhat 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
Functional Safety – Fire and Gas Detection Systems Functional Safety Standards & where gas detection fits
IEC 61508Generic
IEC 62061Machinery
IEC 61513Nuclear
EN 50126Railway
IEC 61511Process
BS EN 50402 IEC 60880 Ed 2prEn 50495 IEC 60079-29-3
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
Functional Safety – Fire and Gas Detection SystemsGas 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
Functional Safety – Fire and Gas Detection SystemsVarious Standards for Fire & Gas Detection Systems
EN 60079 – 10 -1:2009 (EN 1127-1 : 2011)
ISO 31000 : 2009
BS 6079 -1 : 2010
EN 60079 – 1 : 2007
IEC 60079 – 29 – 1 : 2007
IEC 61508 : 2011
EN 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
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
Functional Safety – Fire and Gas Detection Systems Standards currently applied in Projects
Project
Products developed under IEC 61508Application standards written
within the framework of IEC 61508
Machinery safety delivered under IEC 62061
Process safety delivered under IEC 61511ANSI/ISA 84.00.01
Fire and Gas Detection Systems
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
Functional Safety – Fire and Gas Detection Systems Standards that shall be followed in Projects
Project
Products developed under IEC 61508Application standards written
within the framework of IEC 61508
Machinery safety delivered under IEC 62061
Gas Detection delivered under BS EN 50402 / IEC 60079-29-3ANSI/ISA 84.00.07 Fire & Gas
Process safety delivered under IEC 61511ANSI/ISA 84.00.01
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
Functional Safety – Fire and Gas Detection SystemsInterpretation 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
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
1 Gas Dispersion & Sensor Placement2 Principle of Operation – F&G System3 Risk reduction & Role of F&G detectors4 Functional Safety Standards for F&G and Projects.
5 Decision Making on Type Of F&G System6 Applications of F&G Detectors7 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
Functional Safety – Fire and Gas Detection SystemsDecision path - Types of Fire and Gas detection system
Is there a statedSafety function
&Safety integrity?
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
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
Functional Safety – Fire and Gas Detection SystemsF&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
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 SystemsSafety Function - Fire and Gas detection system
Preeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
• 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
1 Gas Dispersion & Sensor Placement
2 Principle of Operation – F&G System3 Risk reduction & Role of F&G detectors4 Functional Safety Standards for F&G and Projects.
5 Decision Making on Type Of F&G System6 Applications of F&G Detectors7 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
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
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
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
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
1 Gas Dispersion & Sensor Placement2 Principle of Operation – F&G System3 Risk reduction & Role of F&G detectors
4 Functional Safety Standards for F&G and Projects.5 Decision Making on Type Of F&G System6 Applications of F&G Detectors7 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
– 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
Functional Safety – Fire and Gas Detection Systems
Thank youPreeju Anirudhan - Product & Applications Manager – F&G / Marketing Manager – Chem, Oil & Gas
Email: [email protected]