The combustion process has always been considered having the potential for a hazardous event which could lead to personnel injury or loss of production. To mitigate this risk, the process industry is now implementing Safety Instrumented Systems which can identify hazardous operating conditions and correctly respond in such a way to bring the combustion process back to a safe operating condition or implement an automatically controlled shutdown sequence to reduce the risk of operator error causing a catastrophic event. Oxygen and combustible flue gas analyzers are now being utilized in these combustion Safety Instrumented Systems (SIS) to identify hazardous operating conditions and automatically return the process to a safe state. The standards of IEC 61511 and API RP 556 will be reviewed as they apply to flue gas analyzers, as well as the process variables of the oxygen and combustible analyzer available for implementation into the SIS system for combustion monitoring, and the resultant actions required to return the process to a safe condition.
This document discusses Safety Integrity Level (SIL) and how it is used to quantify safety in industrial processes. It provides background on the development of international safety standards and defines key terms like SIL, Safety Instrumented Functions (SIF), Probability of Failure on Demand (PFD), and Safe Failure Fraction (SFF). The document explains how hazards analysis is used to determine target SIL levels for safety systems and instrumentation. It also outlines methods for evaluating SIL, including Failure Modes and Effects Analysis (FMEDA) and proven in use testing. Overall, the document provides a comprehensive overview of applying SIL standards to ensure safety in industrial control systems.
Safety is an important consideration in process design. Safety integrity level (or SIL) is often used to describe process safety requirements. However, there are often misconceptions or misunder- standings surrounding SIL. While the general subject, functional safety and SIL, can be highly technical, the general ideas can be distilled down to a few readily understandable concepts. In this paper, we will discuss what SIL is, why it is important, what certification means, and the implications and benefits of that certification to the end user.
Safety instrumented systems angela summers Ahmed Gamal
This document discusses safety instrumented systems (SIS), which are designed to respond to hazardous conditions in industrial plants. An SIS monitors for conditions that could become hazardous and responds by taking actions to prevent or mitigate hazards. Examples provided include a furnace that shuts off fuel valves in response to high pressure and a reactor that opens a coolant valve when temperature rises too high. The document outlines standards for good engineering practices in designing, implementing, and maintaining SIS according to lifecycle phases from planning and design to operations and auditing. Key aspects covered are managing risks to people and procedures, assessing and mitigating risk through assigning safety integrity levels, and proving that SIS designs achieve the desired safety functionality.
The document discusses safety systems used in industrial plants, including emergency shutdown systems (ESD), process shutdown systems (PSD), and fire and gas control systems (F&G). It defines these terms and describes their objectives, typical components, and functions. Safety is measured by factors like average probability of failure on demand (PFDavg) and risk reduction factor (RRF). The document also covers related topics like hazard analysis, risk, reliability, availability, and definitions of key safety terminology.
Practical Safety Instrumentation & Emergency Shutdown Systems for Process Ind...Living Online
COPY THIS LINK INTO YOUR BROWSER FOR MORE INFORMATION: bit.ly/1Htp9ZC
For project managers and engineers involved with hazardous processes, this workshop focuses on the management, planning and execution of automatic safety systems in accordance with IEC 61511, the newly released international standard for process industry safety controls.
IEC 61511 has been recognised by European safety authorities and by USA based process companies as representing the best practices available for the provision of automatic safety systems. The new standard captures many of the well established project and design techniques that have been described since 1996 in ANSI/ISA standard S84 whilst introducing many newer principles based on the master standard IEC 615108. The newly released standard IEC 61511 (published in 3 parts) combines the principles of IEC 61508 and S84 into a practical and easily understood code of practice specifically for end users in the process industries.
This workshop is structured into two major parts to ensure that both managers and engineering staff are trained in the fundamentals of safety system practices. The first part of the workshop, approx the first third, provides an overview of the critical issues involved in managing and implementing safety systems.
WHO SHOULD ATTEND?
Automation/machinery design engineers
Control systems engineers
Chemical or energy process engineers
Instrument/electrical engineers and technicians
Instrument suppliers technical staff
Maintenance supervisors
Project engineers and project managers
COPY THIS LINK INTO YOUR BROWSER FOR MORE INFORMATION: bit.ly/1Htp9ZC
The document discusses functional safety and fire and gas (F&G) systems. It defines functional safety and outlines standards like IEC 61508. F&G systems aim to detect and respond to hazards to reduce risk. Key components discussed include detectors, logic solvers, and final elements. Specific final elements presented are Niagara monitors for delivering water, electric actuators for redundancy, and VDD deluge valves with a fully redundant design. These components are described and their advantages for achieving safety integrity levels are outlined.
SIL = Safety Integrity Level
•Safety systems are becoming increasingly instrumented
•Depending less on human intervention and operator’s ability to respond correctly in a given situation
•Depending more on instrumentation and programmable systems
•SIL requirements are intended to ensure the reliability of such safety instrumented systems
Safety-critical systems are computer systems whose failure could result in injury, death, or environmental damage. Examples include aircraft control systems, nuclear power plant controls, medical devices like pacemakers, and railway signaling systems. These systems require high integrity to avoid hazards and ensure safety. Techniques like developing diverse redundant systems can improve safety by detecting and tolerating a wider range of faults.
This document discusses Safety Integrity Level (SIL) and how it is used to quantify safety in industrial processes. It provides background on the development of international safety standards and defines key terms like SIL, Safety Instrumented Functions (SIF), Probability of Failure on Demand (PFD), and Safe Failure Fraction (SFF). The document explains how hazards analysis is used to determine target SIL levels for safety systems and instrumentation. It also outlines methods for evaluating SIL, including Failure Modes and Effects Analysis (FMEDA) and proven in use testing. Overall, the document provides a comprehensive overview of applying SIL standards to ensure safety in industrial control systems.
Safety is an important consideration in process design. Safety integrity level (or SIL) is often used to describe process safety requirements. However, there are often misconceptions or misunder- standings surrounding SIL. While the general subject, functional safety and SIL, can be highly technical, the general ideas can be distilled down to a few readily understandable concepts. In this paper, we will discuss what SIL is, why it is important, what certification means, and the implications and benefits of that certification to the end user.
Safety instrumented systems angela summers Ahmed Gamal
This document discusses safety instrumented systems (SIS), which are designed to respond to hazardous conditions in industrial plants. An SIS monitors for conditions that could become hazardous and responds by taking actions to prevent or mitigate hazards. Examples provided include a furnace that shuts off fuel valves in response to high pressure and a reactor that opens a coolant valve when temperature rises too high. The document outlines standards for good engineering practices in designing, implementing, and maintaining SIS according to lifecycle phases from planning and design to operations and auditing. Key aspects covered are managing risks to people and procedures, assessing and mitigating risk through assigning safety integrity levels, and proving that SIS designs achieve the desired safety functionality.
The document discusses safety systems used in industrial plants, including emergency shutdown systems (ESD), process shutdown systems (PSD), and fire and gas control systems (F&G). It defines these terms and describes their objectives, typical components, and functions. Safety is measured by factors like average probability of failure on demand (PFDavg) and risk reduction factor (RRF). The document also covers related topics like hazard analysis, risk, reliability, availability, and definitions of key safety terminology.
Practical Safety Instrumentation & Emergency Shutdown Systems for Process Ind...Living Online
COPY THIS LINK INTO YOUR BROWSER FOR MORE INFORMATION: bit.ly/1Htp9ZC
For project managers and engineers involved with hazardous processes, this workshop focuses on the management, planning and execution of automatic safety systems in accordance with IEC 61511, the newly released international standard for process industry safety controls.
IEC 61511 has been recognised by European safety authorities and by USA based process companies as representing the best practices available for the provision of automatic safety systems. The new standard captures many of the well established project and design techniques that have been described since 1996 in ANSI/ISA standard S84 whilst introducing many newer principles based on the master standard IEC 615108. The newly released standard IEC 61511 (published in 3 parts) combines the principles of IEC 61508 and S84 into a practical and easily understood code of practice specifically for end users in the process industries.
This workshop is structured into two major parts to ensure that both managers and engineering staff are trained in the fundamentals of safety system practices. The first part of the workshop, approx the first third, provides an overview of the critical issues involved in managing and implementing safety systems.
WHO SHOULD ATTEND?
Automation/machinery design engineers
Control systems engineers
Chemical or energy process engineers
Instrument/electrical engineers and technicians
Instrument suppliers technical staff
Maintenance supervisors
Project engineers and project managers
COPY THIS LINK INTO YOUR BROWSER FOR MORE INFORMATION: bit.ly/1Htp9ZC
The document discusses functional safety and fire and gas (F&G) systems. It defines functional safety and outlines standards like IEC 61508. F&G systems aim to detect and respond to hazards to reduce risk. Key components discussed include detectors, logic solvers, and final elements. Specific final elements presented are Niagara monitors for delivering water, electric actuators for redundancy, and VDD deluge valves with a fully redundant design. These components are described and their advantages for achieving safety integrity levels are outlined.
SIL = Safety Integrity Level
•Safety systems are becoming increasingly instrumented
•Depending less on human intervention and operator’s ability to respond correctly in a given situation
•Depending more on instrumentation and programmable systems
•SIL requirements are intended to ensure the reliability of such safety instrumented systems
Safety-critical systems are computer systems whose failure could result in injury, death, or environmental damage. Examples include aircraft control systems, nuclear power plant controls, medical devices like pacemakers, and railway signaling systems. These systems require high integrity to avoid hazards and ensure safety. Techniques like developing diverse redundant systems can improve safety by detecting and tolerating a wider range of faults.
Reliability Instrumented System | Arrelic Insights Arrelic
An approach that strays from the conventional, coupled with
consistency, enables us to contribute to the company's overall
growth and success.
This Insights talks about RIS Process and applications
This document provides an overview and definitions related to Safety Instrumented Systems (SIS). It discusses the need for SIS to protect personnel, equipment, and the environment from hazardous events in industries like chemical and oil & gas. SIS are designed to reduce the likelihood or impact of emergencies. The document defines common SIS terms and describes the basic components and purpose of SIS, which include sensors to detect process parameters, a logic solver to determine necessary actions, and final control elements like valves to isolate the process. It also discusses the concept of layers of protection to prevent and mitigate hazardous events, with SIS comprising the final active prevention layer.
lain Engels
Product Manager Level & Safety Applications Consultant
Endress+Hauser
Alain werkt bij Endress+ Hauser sinds 1984.
Hij heeft verschillende functies gehad zoals Product Manager van Druk, Temperatuur en Niveaumetingen.
In paralell was hij ook Industrie specialist voor Chemie & Oil & Gas en ATEX, SIL en PED.
Critical Review of PSM In Petroleum Industry | Mr. Hirak Dutta, Executive Di...Cairn India Limited
This document summarizes the key points from a presentation on process safety management in India's petroleum industry. It notes that India has become a major exporter of petroleum products, with over 200 million metric tons of annual refining capacity and significant crude oil and gas production. It outlines the pillars of process safety like operational integrity and discusses taking a systemic approach. It emphasizes the importance of recognizing warning signs to avoid accidents and highlights lessons around focusing on leading indicators and inherent safety principles. The document concludes by outlining the Oil Industry Safety Directorate's focus on key drivers of process safety like procedures, hazard identification, and managing change.
The document discusses safety instrumentation and safety integrity levels (SILs). It provides examples of major industrial accidents from 1974 to 2005 and their causes. These include failures of safety systems and instrumentation. The document then discusses key aspects of safety instrumented systems (SIS) such as their hardware components, separation from process controls, definition, and role in risk reduction. It introduces SIL ratings from 1 to 4 which define the reliability of a SIS based on its risk reduction factor and probability of failure on demand.
This document explains Safety Integrity Levels (SIL) which are used to quantify safety requirements for Safety Instrumented Systems. It discusses what SIL is, the four SIL levels and their required reliability, how SIL ratings are determined through a risk assessment process, and how hazards are protected against through a layered approach. The document also outlines the SIL life cycle including design, realization, and operation phases, how equipment failures can occur, and how a Safety Instrumented Function's performance is quantified through its Probability of Failure on Demand. It provides information on how components like actuators can be certified as "suitable for use" at a given SIL level and the role of proof and diagnostic testing.
This document is an engineering handbook on fire and gas systems published by Kenexis Consulting Corporation. It provides an overview of Kenexis, which is an engineering consulting company focused on implementing safety systems in process plants. The handbook was written by several authors from Kenexis who have experience designing fire and gas systems and safety instrumented systems. It aims to distill best practices for performance-based fire and gas system design based on risk analysis methods from the ISA technical report on this topic. The handbook is intended as a practical reference for everyday use in fire and gas system design.
This document provides an introduction to methodologies for evaluating the safety integrity level (SIL) of safety instrumented functions (SIF) through determining the probability of failure on demand (PFD) of the SIF. It describes the safety lifecycle model and how SIL evaluation fits in. The document focuses on performance-based approaches for SIL evaluation and provides examples of SIS architectures without promoting any single methodology. It evaluates the whole SIF from sensors to final elements. The user is cautioned to understand the assumptions and limitations of the methodologies described.
This document discusses Safety Instrumented Systems (SIS) and methods for determining risk reduction requirements. An SIS monitors industrial processes for dangerous conditions and executes actions to prevent or mitigate hazardous events. The document describes various methods to determine the necessary level of risk reduction for a given process, including risk graphs and Layer of Protection Analysis, both of which consider the consequences, frequency, possibility of avoidance, and probability of occurrence of an event. The determined risk reduction requirement is characterized by a Safety Integrity Level (SIL) on a scale of 1 to 4. An SIS provides risk reduction by successfully performing its safety functions, with its effectiveness measured by its probability of failure on demand (PFD).
The document discusses Safety Instrumented Systems (SIS) and the Safety Life Cycle as defined by ANSI/ISA 84.00.01-2004. It outlines the steps in the Safety Life Cycle from initial Hazard and Risk Assessment to determine Safety Instrumented Functions (SIFs) and required Safety Integrity Levels (SILs), to design, installation, and ongoing maintenance of SIS including functional proof testing. The Safety Life Cycle is meant to guide safety systems through all stages from initial assessment to eventual decommissioning to minimize risk in industrial processes.
Process Safety Life Cycle Management: Best Practices and ProcessesMd Rahaman
Learn how to transform your current process safety program to deliver intelligent and integrated safety solutions that can directly affect the bottom line, while simultaneously improving process and personnel safety.
Introduction to Functional Safety and SIL CertificationISA Boston Section
This overview session will acquaint attendees with the key concepts in the IEC 61508 standard for functional safety of electrical/electronic and programmable electronic systems. An introduction is provided to safety integrity levels (SIL), the safety lifecycle and the requirements needed to achieve a functional safety certificate. Information will be provided on documentation requirements and an introduction to the basic objectives of product design for functional safety.
Process safety aims to prevent incidents involving hazardous materials that could endanger workers, property, and the environment. It involves applying engineering and operating practices to control hazards. Key elements of process safety management include process hazard analysis, operating procedures, employee participation, training, contractor management, pre-startup safety reviews, mechanical integrity programs, emergency response planning, compliance audits, and incident investigation. The goal is to anticipate, identify, evaluate, and control hazards to protect people and prevent accidents.
Safety Lifecycle Management - Emerson Exchange 2010 - Meet the Experts Mike Boudreaux
The document discusses process safety and functional safety. It covers many topics related to ensuring safety in industrial processes, including safety lifecycles, risk assessments, safety instrumented systems, standards like IEC 61511, and maintaining safety through proper design, installation, operation and modification of systems.
The document discusses burner management systems (BMS) and how programmable electronic systems (PES) can be used for burner control while ensuring safety. It outlines several key requirements for PES-based BMS to be certified, including using redundant safety-related PES, obtaining independent safety certification, and the designer demonstrating proper development and testing practices. The document also describes various safety features that can be designed into BMS, such as input/output monitoring, guarded outputs, processor watchdog timers, and power monitoring. It discusses architectures for safety programmable logic controllers (PLCs) including 1oo1D (one out of one with diagnostics) and 1oo2D (one out of two with diagnostics).
This document discusses improving health and safety management practices in West Africa's construction industry. It begins by noting the high accident rates in construction and the risks workers face. The objectives are to raise safety awareness, challenge stakeholders to do more to prevent accidents, and develop best practices. It then examines factors that contribute to accidents such as lack of safety training and policies. Statistics on fatal injuries in the UK construction industry are also provided. The document advocates for creating a health and safety management model that includes a safety policy, addresses legal requirements, and fosters a safety culture.
The document discusses process safety and functional safety. It covers topics like hazard and risk assessments, safety instrumented systems (SIS), safety integrity levels (SIL), and the safety lifecycle described in standards like IEC 61511. The purpose of process safety management is to reduce the frequency and severity of chemical accidents by implementing layers of protection that can include inherently safer design, equipment reliability, formal safety assessments, operating procedures, training and emergency response. Functional safety focuses specifically on instrumented safety systems and ensuring safety instrumented functions are designed and maintained to a reliability suitable for their risk reduction purpose.
The document summarizes efforts to improve production yields for catalytic bead gas sensors from 20-40% to 80-95% after the manufacturing process was moved. Critical process steps were identified and improved through tools like root cause analysis and design of experiments. Process upgrades like chemical application methods and quality controls helped address defects. Testing procedures were enhanced and hands-on training provided. The changes reduced scrap and improved productivity while supporting $10-12M in annual business.
The reliable identification of low combustion oxygen in a red heater or boiler has always been critical to the effectiveness of the Burner Management System for proper control and safety.
Low emission burners and aggressive ring control points to achieve increased efficiency and emission reductions have driven the industry to tighter control measures. But tighter control measures also hold a greater potential for combustion damage. Reducing the risk of a combustion event has become a priority and has led to the implementation of Safety Instrumented Systems (SIS). This additional layer of safety is added to the Basic Process Control System.
Reliability Instrumented System | Arrelic Insights Arrelic
An approach that strays from the conventional, coupled with
consistency, enables us to contribute to the company's overall
growth and success.
This Insights talks about RIS Process and applications
This document provides an overview and definitions related to Safety Instrumented Systems (SIS). It discusses the need for SIS to protect personnel, equipment, and the environment from hazardous events in industries like chemical and oil & gas. SIS are designed to reduce the likelihood or impact of emergencies. The document defines common SIS terms and describes the basic components and purpose of SIS, which include sensors to detect process parameters, a logic solver to determine necessary actions, and final control elements like valves to isolate the process. It also discusses the concept of layers of protection to prevent and mitigate hazardous events, with SIS comprising the final active prevention layer.
lain Engels
Product Manager Level & Safety Applications Consultant
Endress+Hauser
Alain werkt bij Endress+ Hauser sinds 1984.
Hij heeft verschillende functies gehad zoals Product Manager van Druk, Temperatuur en Niveaumetingen.
In paralell was hij ook Industrie specialist voor Chemie & Oil & Gas en ATEX, SIL en PED.
Critical Review of PSM In Petroleum Industry | Mr. Hirak Dutta, Executive Di...Cairn India Limited
This document summarizes the key points from a presentation on process safety management in India's petroleum industry. It notes that India has become a major exporter of petroleum products, with over 200 million metric tons of annual refining capacity and significant crude oil and gas production. It outlines the pillars of process safety like operational integrity and discusses taking a systemic approach. It emphasizes the importance of recognizing warning signs to avoid accidents and highlights lessons around focusing on leading indicators and inherent safety principles. The document concludes by outlining the Oil Industry Safety Directorate's focus on key drivers of process safety like procedures, hazard identification, and managing change.
The document discusses safety instrumentation and safety integrity levels (SILs). It provides examples of major industrial accidents from 1974 to 2005 and their causes. These include failures of safety systems and instrumentation. The document then discusses key aspects of safety instrumented systems (SIS) such as their hardware components, separation from process controls, definition, and role in risk reduction. It introduces SIL ratings from 1 to 4 which define the reliability of a SIS based on its risk reduction factor and probability of failure on demand.
This document explains Safety Integrity Levels (SIL) which are used to quantify safety requirements for Safety Instrumented Systems. It discusses what SIL is, the four SIL levels and their required reliability, how SIL ratings are determined through a risk assessment process, and how hazards are protected against through a layered approach. The document also outlines the SIL life cycle including design, realization, and operation phases, how equipment failures can occur, and how a Safety Instrumented Function's performance is quantified through its Probability of Failure on Demand. It provides information on how components like actuators can be certified as "suitable for use" at a given SIL level and the role of proof and diagnostic testing.
This document is an engineering handbook on fire and gas systems published by Kenexis Consulting Corporation. It provides an overview of Kenexis, which is an engineering consulting company focused on implementing safety systems in process plants. The handbook was written by several authors from Kenexis who have experience designing fire and gas systems and safety instrumented systems. It aims to distill best practices for performance-based fire and gas system design based on risk analysis methods from the ISA technical report on this topic. The handbook is intended as a practical reference for everyday use in fire and gas system design.
This document provides an introduction to methodologies for evaluating the safety integrity level (SIL) of safety instrumented functions (SIF) through determining the probability of failure on demand (PFD) of the SIF. It describes the safety lifecycle model and how SIL evaluation fits in. The document focuses on performance-based approaches for SIL evaluation and provides examples of SIS architectures without promoting any single methodology. It evaluates the whole SIF from sensors to final elements. The user is cautioned to understand the assumptions and limitations of the methodologies described.
This document discusses Safety Instrumented Systems (SIS) and methods for determining risk reduction requirements. An SIS monitors industrial processes for dangerous conditions and executes actions to prevent or mitigate hazardous events. The document describes various methods to determine the necessary level of risk reduction for a given process, including risk graphs and Layer of Protection Analysis, both of which consider the consequences, frequency, possibility of avoidance, and probability of occurrence of an event. The determined risk reduction requirement is characterized by a Safety Integrity Level (SIL) on a scale of 1 to 4. An SIS provides risk reduction by successfully performing its safety functions, with its effectiveness measured by its probability of failure on demand (PFD).
The document discusses Safety Instrumented Systems (SIS) and the Safety Life Cycle as defined by ANSI/ISA 84.00.01-2004. It outlines the steps in the Safety Life Cycle from initial Hazard and Risk Assessment to determine Safety Instrumented Functions (SIFs) and required Safety Integrity Levels (SILs), to design, installation, and ongoing maintenance of SIS including functional proof testing. The Safety Life Cycle is meant to guide safety systems through all stages from initial assessment to eventual decommissioning to minimize risk in industrial processes.
Process Safety Life Cycle Management: Best Practices and ProcessesMd Rahaman
Learn how to transform your current process safety program to deliver intelligent and integrated safety solutions that can directly affect the bottom line, while simultaneously improving process and personnel safety.
Introduction to Functional Safety and SIL CertificationISA Boston Section
This overview session will acquaint attendees with the key concepts in the IEC 61508 standard for functional safety of electrical/electronic and programmable electronic systems. An introduction is provided to safety integrity levels (SIL), the safety lifecycle and the requirements needed to achieve a functional safety certificate. Information will be provided on documentation requirements and an introduction to the basic objectives of product design for functional safety.
Process safety aims to prevent incidents involving hazardous materials that could endanger workers, property, and the environment. It involves applying engineering and operating practices to control hazards. Key elements of process safety management include process hazard analysis, operating procedures, employee participation, training, contractor management, pre-startup safety reviews, mechanical integrity programs, emergency response planning, compliance audits, and incident investigation. The goal is to anticipate, identify, evaluate, and control hazards to protect people and prevent accidents.
Safety Lifecycle Management - Emerson Exchange 2010 - Meet the Experts Mike Boudreaux
The document discusses process safety and functional safety. It covers many topics related to ensuring safety in industrial processes, including safety lifecycles, risk assessments, safety instrumented systems, standards like IEC 61511, and maintaining safety through proper design, installation, operation and modification of systems.
The document discusses burner management systems (BMS) and how programmable electronic systems (PES) can be used for burner control while ensuring safety. It outlines several key requirements for PES-based BMS to be certified, including using redundant safety-related PES, obtaining independent safety certification, and the designer demonstrating proper development and testing practices. The document also describes various safety features that can be designed into BMS, such as input/output monitoring, guarded outputs, processor watchdog timers, and power monitoring. It discusses architectures for safety programmable logic controllers (PLCs) including 1oo1D (one out of one with diagnostics) and 1oo2D (one out of two with diagnostics).
This document discusses improving health and safety management practices in West Africa's construction industry. It begins by noting the high accident rates in construction and the risks workers face. The objectives are to raise safety awareness, challenge stakeholders to do more to prevent accidents, and develop best practices. It then examines factors that contribute to accidents such as lack of safety training and policies. Statistics on fatal injuries in the UK construction industry are also provided. The document advocates for creating a health and safety management model that includes a safety policy, addresses legal requirements, and fosters a safety culture.
The document discusses process safety and functional safety. It covers topics like hazard and risk assessments, safety instrumented systems (SIS), safety integrity levels (SIL), and the safety lifecycle described in standards like IEC 61511. The purpose of process safety management is to reduce the frequency and severity of chemical accidents by implementing layers of protection that can include inherently safer design, equipment reliability, formal safety assessments, operating procedures, training and emergency response. Functional safety focuses specifically on instrumented safety systems and ensuring safety instrumented functions are designed and maintained to a reliability suitable for their risk reduction purpose.
The document summarizes efforts to improve production yields for catalytic bead gas sensors from 20-40% to 80-95% after the manufacturing process was moved. Critical process steps were identified and improved through tools like root cause analysis and design of experiments. Process upgrades like chemical application methods and quality controls helped address defects. Testing procedures were enhanced and hands-on training provided. The changes reduced scrap and improved productivity while supporting $10-12M in annual business.
The reliable identification of low combustion oxygen in a red heater or boiler has always been critical to the effectiveness of the Burner Management System for proper control and safety.
Low emission burners and aggressive ring control points to achieve increased efficiency and emission reductions have driven the industry to tighter control measures. But tighter control measures also hold a greater potential for combustion damage. Reducing the risk of a combustion event has become a priority and has led to the implementation of Safety Instrumented Systems (SIS). This additional layer of safety is added to the Basic Process Control System.
A sensor selection guide when you need to measure
pH, ORP, Turbidity, Specific Ion, Conductivity, Water Analyzers, Dissolved Oxygen
Typical industrial applications are: Petro-Chemical Processing, Biotech & Pharmaceutical, Waste Water Treatment, Chemical Processing, Power Generation, Food & Beverage, Semi-Conductor, Industrial Water, Drinking Water
The Brooks® Ar-MiteTM is a reliable, low flow metal tube flowmeter with 316L stainless steel wetted parts. The magnetically coupled indicator provides a highly reliable method of indication. This model is a practical and economical approach to low flow rate indication for high pressure and difficult to handle fluids. Optional accessories include 4-20 mA output, Needle Valve, Flow Controllers and Alarms.
Instrumentation, Automation and Control Solutions for the Grain IndustryIves Equipment
Over a century and a half later, mechanized equipment is now an essential part of the grain industry, from planting and growing to harvesting, handling, and milling grain. Your challenges are still the same as those of nineteenth century grain operators, though – how can you improve processes and cut costs while also increasing safety?
The HYDRA analyzers are a family of nitrogen analyzers that measure ammonium or nitrate using a single integrated sensor. The HYDRA-NH4 and HYDRA-NO3 sensors measure these compounds in municipal and environmental water applications. Key features include automatic compensation for interfering ions and temperature, integrated spray cleaning, and configurable alarm outputs. The sensors have replaceable electrodes and require minimal maintenance.
Module 3 flammable gas detection, american fork fire rescuejhendrickson1983
This document describes lower explosive limit (LEL) gas sensors and their readings. It discusses that most LEL sensors are calibrated to methane or pentane and read measurements up to the LEL level. Beyond the LEL there is a fire hazard. It also describes the advantages and disadvantages of different sensor types, including wheatstone bridge sensors, catalytic bead sensors, and metal oxide sensors. Understanding how LEL sensors work and interpreting their readings is important for safety in identifying flammable gas risks.
Five men died trying to save each other after inhaling toxic gases in an underground manure pit. Bill Hofer was the first to collapse after inhaling a combination of toxic gases in the pit. The other four men then tried to save Hofer and each other but all died within five minutes from the deadly fumes. Those who died include Bill Hofer, his uncle Carl Theuerkauf Sr., and Carl's two sons and grandson, making it believed to be the worst farm accident in Michigan's history. Investigators determined the men were almost finished emptying the partially covered 12-foot deep concrete manure pit using a pump when it clogged. Hofer descended to clear the block and the others followed in attempts
Source: Honeywell
Gas detection basics
Gas detection sensing technology
Sensor location
SIL in gas detection
Calibration / maintenance
ATEX
www.ie-net.be/reg
www.regeltechnieken.org
The document discusses two main types of oxygen analyzers: zirconia and paramagnetic. Zirconia analyzers work by generating a voltage based on the difference in oxygen concentration between a process gas and reference gas in contact with a zirconia element. Paramagnetic analyzers detect oxygen concentration based on the displacement of a dumbbell in a magnetic field caused by oxygen's paramagnetic properties. The document also provides details on calibrating, testing, and maintaining zirconia oxygen analyzers.
Regulatory modifications have raised important issues in design and use of industrial safety systems. Certain changes in IEC 61508, now being widely implemented, mean that designers and users who desire full compliance must give new consideration to topics such as SIL levels and the transition to new methodologies.
1) IEC 61508 is an international standard for functional safety of electrical, electronic, and programmable electronic safety-related systems. It standardizes safety requirements and assessment methodologies that can be applied across industries.
2) The nuclear industry could benefit from using components certified to IEC 61508, as it offers advantages in technical rigor and economics. Components certified as SIL 2 or higher have undergone reliability and correctness assessments that align with nuclear industry needs.
3) IEC 61508 certification of individual components, like sensors, controllers, and actuators, remains compatible with existing nuclear safety system requirements and could facilitate commercial-grade dedication or suitability evaluations for digital equipment.
This document discusses safety standards for critical systems and proposes a new concept called Assured Reliability and Resilience Level (ARRL). It notes that while safety standards aim to reduce risk, their requirements differ across domains. The document argues that Safety Integrity Levels (SIL) alone are not sufficient and that Quality of Service is a more holistic criterion. It also notes standards provide little guidance on composing systems from components. The ARRL concept aims to address these issues and complement SIL by considering factors like component trustworthiness and fault behavior. The document suggests ARRL could help foster cross-domain safety engineering.
ARRL: A Criterion for Composable Safety and Systems EngineeringVincenzo De Florio
While safety engineering standards define rigorous and controllable
processes for system development, safety standards’ differences in distinct
domains are non-negligible. This paper focuses in particular on the aviation,
automotive, and railway standards, all related to the transportation market.
Many are the reasons for the said differences, ranging from historical reasons,
heuristic and established practices, and legal frameworks, but also from the
psychological perception of the safety risks. In particular we argue that the
Safety Integrity Levels are not sufficient to be used as a top level requirement
for developing a safety-critical system. We argue that Quality of Service is a
more generic criterion that takes the trustworthiness as perceived by users better
into account. In addition, safety engineering standards provide very little
guidance on how to compose safe systems from components, while this is the
established engineering practice. In this paper we develop a novel concept
called Assured Reliability and Resilience Level as a criterion that takes the
industrial practice into account and show how it complements the Safety
Integrity Level concept.
Technical Paper for ASPF 2012 - Choosing the right SISAlvin CJ Chin
This document discusses choosing the right safety instrumented system (SIS) for process plants. It notes that plant owners must balance safety, profitability, and minimizing downtime. The best SIS options minimize unnecessary shutdowns during maintenance and upgrades while still providing high safety (SIL3) protection. Well-designed standalone SIS that permit online maintenance and upgrades without shutting down the entire plant can save millions of dollars in avoided downtime costs each day. The document advocates that plant owners directly select the most suitable SIS rather than relying only on engineering contractors.
This document provides recommendations for process safety leading and lagging metrics. It defines three types of metrics: lagging metrics based on incidents that meet reporting thresholds, leading metrics that indicate performance of protection layers, and internal lagging metrics for less severe incidents or near misses. Metrics are described that companies can incorporate into their process safety management systems to continuously improve safety performance. The document aims to promote common, consistent metrics across industry.
There are four SILs — SIL 1, SIL 2, SIL 3, and SIL 4. The higher the SIL, the greater the risk of failure. And the greater the risk of failure, the stricter the safety requirements
Safety instrumented systems (SIS) are designed to respond to hazardous conditions in industrial plants. An SIS monitors for conditions that could lead to hazards and responds by taking actions to prevent or mitigate hazards. Examples include high fuel gas pressure shutting off main valves or high reactor temperature opening a coolant valve. Standards like ISA 84.01 and IEC 61508/61511 provide guidelines for engineering practices to ensure SIS integrity through their lifecycle from planning and design to operations and maintenance. A key aspect is assessing risk and assigning a safety integrity level to guide system reliability design.
The document discusses three standards related to safety integrity levels (SIL): IEC 61508, IEC 61511, and ANSI/ISA S84.01. It provides an overview of each standard, including their parts and scope. The key points are that IEC 61508 and 61511 define SIL on a scale from 1 to 4 based on reliability requirements for safety instrumented systems (SIS), while ANSI/ISA S84.01 was developed in parallel and also adopted by ANSI. The document then discusses various methods for assigning SILs to safety instrumented functions, including consequence-based, risk matrix, layered risk matrix, and layer of protection analysis (LOPA).
Reliability Instrumented System | Arrelic InsightsArrelic
Reliability Instrumented System is characterized by a relative level of hazard lessening gave by a security work, or to indicate an objective level of hazard decrease. In straight forward terms, RIS is an estimation of execution required for a Safety Instrumented Function.
Industrial safety engineering, oil,gas & refineryMahfuz Haq
Safety is a precondition for any kind of industries. Safety condition of being protected against
physical, social, financial, or other types or consequences of failure, damage, error, accidents, harm
or any other event which could be considered non-desirable. Lack of safety results in accidents
which may result in caviar damage to the business and workforce as well. Every industry has their
own safety instructions but considered to oil/gas/refineries, those safety precautions may lack
behind as their operative product is highly flammable (possesses high hazard) and their business
strategies are impacted not only by their own decisions but also international and national
decisions.
Documented evidence with regard to the adherence to the required safety integrity level (SIL) within the scope of the
safety life cycle has to be delivered in order to proof that the imple-mentation of safety systems (Safety Instrumented
Systems SIS) in the process industry has been executed according to professional standards. When carrying out the hazard
analysis and the risk assessment, safety functions (Safety Instrumented Function SIF) will be estab-lished and evaluated
against a required SIL. The achievable SIL both for systematic defaults and for random failures can be established for each
safety function being carried out by means of a safety system. The established SIL has to be in conformity with or better
than the required SIL. The engineers of the weyer group will establish the respective SIL-level of the plant, taking the data
delivered by the manufacturers as the calculation base.
This document discusses how applying process safety best practices can improve operational technology (OT) cybersecurity. It outlines the five independent protection layers (IPLs) for process safety - inventory and configuration management, automatic process controls, human intervention, safety instrumented systems, and physical protection. Applying best practices to each IPL layer improves OT cybersecurity by making any operational changes from cyber attacks more apparent so they can be addressed quicker. Effective configuration management and change control are especially important, as the Stuxnet attack showed how undetected changes could damage equipment over time. Overall, following process safety practices enhances control performance, alarms, interfaces, and system resilience while countering modern cyber threats.
The article discusses writing a Safety Requirement Specification (SRS), which is the last stage of the analysis phase for a Safety Instrumented System (SIS) lifecycle. It outlines the key components of an SRS, including input information, functional requirements, and safety integrity requirements for each safety instrumented function. The article provides examples of the types of details to include in an SRS, such as the safe state of the process, sources of demand on the system, target safety integrity levels, and requirements for resetting the system. Developing a thorough SRS according to the findings of the hazard and risk assessment is important, as it forms the input for the design and realization phase of the SIS lifecycle.
The document discusses Safety Instrumented Systems (SIS) and the Safety Life Cycle as defined by ANSI/ISA 84.00.01-2004. It outlines the steps in the Safety Life Cycle from initial Hazard and Risk Assessment to determine Safety Instrumented Functions (SIFs) and required Safety Integrity Levels (SILs), to design, installation, and ongoing maintenance of SIS including functional proof testing. The Safety Life Cycle is meant to guide safety systems through all stages from initial assessment to eventual decommissioning to minimize risk in industrial processes.
This document discusses risk analysis and environmental hazard management. It begins by defining risk, hazard, and toxicity. It then outlines the steps involved in hazard identification, including HAZID, HAZOP, and HAZAN. The document presents a case study of a hypothetical gas collecting station, identifying potential accidents and hazards. It discusses quantitative and qualitative approaches to risk analysis, including calculating a fire and explosion index. The document concludes by discussing hazard management strategies like preventative measures, control measures, fire protection, relief operations, and the importance of training personnel on safety.
The document discusses High-Integrity Pressure Protection Systems (HIPPS), which are instrumented systems that can provide overpressure protection as an alternative to pressure relief devices. A HIPPS includes sensors, logic solvers, and final control elements arranged to reach a fail-safe state if overpressure occurs. HIPPS are safety instrumented systems that must meet standards like IEC 61511. They require careful documentation, design, testing and maintenance to ensure the level of protection is equal to or greater than a conventional pressure relief device system.
RiskWatch for Physical & Homeland Security™CPaschal
RiskWatch for Physical and Homeland Security™ assists the user in conducting automated risk analyses, physical security reviews, audits and vulnerability assessments of facilities and personnel. Security threats addressed include crimes against property, crimes against people, equipment of systems failure, terrorism ,natural disasters, fire and bomb threats. Question sets include entry control, perimeters, fire, facilities management, guards, including a specialized set of questions for the maritime/shipping industry. New ASP functionality allows the organization in question to put the entire questionnaire process on it\'s server, where users can easily log in by ID # and answer questions appropriative to their job. From there, all answers are instantly imported into the RiskWatch for Physical and Homeland Security™ program.
This document discusses safety audits and compliance with NFPA 70E standards. It notes that safety audits ensure organizations follow proper safety regulations to avoid injuries, damage, and costs. NFPA 70E specifically addresses electrical safety in workplaces and complying with it helps save lives, reduce liability, and prevent downtime and revenue losses. The document provides details on NFPA 70E's definitions, requirements for personal protective equipment, and establishing electrically safe work environments. It also gives examples of other NFPA standards related to fire safety and prevention.
Similar to Application of Combustion Analyzers in Safety Instrumented Systems (20)
Providing uniform heat to semiconductor devices in degassing chambers is essential in extracting impurities. This can only be achieved if a heating device has the proper fit and temperature uniformity for a given chamber. It is for this very application that BCE was approached by a large semiconductor company from Silicon Valley. In order to heat this company’s semiconductor wafers, it was critical that the heating device be manufactured to fit precisely into a large and circular degassing chamber posing manufacturing challenges due to dimensional and application parameters. BCE was able to provide extensive design consultations, 3D CAD modeling and lean manufacturing capabilities to this semiconductor giant at a competitive price. All these services were rendered while catering to all requirements needed to successfully manufacture their products.
A compact, fast responding electric heating element for clean gases in fuel cell, bio-med, laboratory, food, and pharmaceutical applications. The SuperCirc gas heater is designed for applications where fast heating of clean gases is required. All parts exposed to gas flow are constructed of 316SS (other materials available) rather than exposing process media to exposed resistance elements. This ensures that no foreign matter contaminates gas.
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One of the biggest challenges facing the vacuum industry is to collect multiple readings from complex assemblies while being limited by the number of existing feedthrough ports in a vacuum chamber. With BCE’s Multi-TC, Flanged Feedthrough, companies no longer need to invest in adding more ports for a greater collection of temperatures from a vacuum environment as multiple thermocouples are embedded in just one feedthrough. The number, type and lengths of the thermocouples can be altered to match specific application requirements meeting each customers’ unique needs. As the thermocouples can be adapted to meet unique design constraints, so can this feedthrough’s flange. All sizes used are standard and are easily mountable with readily available hardware. No complicated assemblies are required for the most complicated of vacuum setups.
With most vacuum feedthroughs, troubleshooting can be difficult as well when multiple fixed elements are involved. If one element fails, generally the entire vacuum feedthrough is rendered useless. With BCE’s Multi-TC, Flanged Feedthrough, arduous troubleshooting procedures are a thing of the past. In fact, this feedthrough’s thermocouples are replaceable as they can be extracted from the compression fittings with great ease. This means that if thermocouples fail, they can be removed, tested and replaced within minutes. Thus, this no-hassle design allows for faster, more accurate and more cost-effective thermal data collection. Trust BCE’s Multi-TC, Flanged Feedthrough for your most complicated thermal detection needs.
Practice:
Well made, clamped, and temperature stabilized circular O-rings should be used in the design of
reliable, reusable and long life seals in vacuum sealing applications. Benefits:
Leak free flanges as well as low/undetectable outgassing of the elastomeric materials can be achieved at pressure levels as low as 10-8 Torr by using well made O-rings in a static vacuum seal environment. The use of O-rings has provided ease for running environmental tests on the ground using space simulation chambers.
The Air Process heater will provide hot air and gas up to 1000 degree Fahrenheit (540 C) with infinite control by varying the voltage and air velocity supplied. Units are fitted with a tubing "T" for convenient power lead outlet, while larger diameters can be supplied with post terminals on the sheath for direct electrical connections.
Orion Instruments specializes in high-visibility magnetic level indication and high-accuracy magnetostrictive level transmitters. Magnetic level indicators provide high visibility local indication of liquid level in tanks and vessels.
BARTON 7000 Series liquid turbine meters are designed for a broad range of precise liquid measurement applications. Based on more than 40 years of turbine manufacturing experience, this built-to-order series features a range of sizes, materials, bearing systems, and options.
DCS/PLC and SCADA control systems, though they provide immense capability, share a common weakness. Both are subject to cyber attack from external sources. The potential impact of this vulnerability should not be dismissed. An annunciator system can be put in place that will monitor critical process elements and provide notification of abnormalities. The systems, whether hardwired or software based, are isolated, allowing them to act as a failsafe or backup to the main control and monitoring system.
Companies in the process industry need the ability to visually monitor liquid levels in vessels (boilers, storage tanks, processing units, etc.). Traditionally, armored glass sight gauges have been used. However, many companies want an alternative to sight gauges to avoid problems such as breakage, leaks, or bursting at high pressures and extreme temperatures. In addition, the visibility of the sight glass can be poor and often affected by moisture, corrosion, or oxidation.
Magnetic level indicators (MLIs) do not have the shortcomings of glass sight gauges and are suitable for a wide variety of installations.
Designed for semiconductor, MOCVD and other gas flow control applications, the GF100 series exceeds the semiconductor industry standard for reliability, ensuring repeatable, highly stable performance over time. Standard MultiFlo technology enables one MFC to support thousands of gas types and range combinations without removing it from the gas line or compromising on accuracy.
Process Heaters, Furnaces and Fired Heaters: Improving Efficiency and Reducin...Belilove Company-Engineers
A process heater is a direct-fired heat exchanger that uses the hot gases of combustion to raise the temperature of a feed owing through coils of tubes aligned throughout the heater. Depending on the use, these are also called furnaces or red heaters. Some heaters simply deliver the feed at a predetermined temperature to the next stage of the reaction process; others perform reactions on the feed while it travels through the tubes.
Process level measurement has greatly evolved over the years with new technologies. Instrumentation engineers have more demanding requirements that make it essential to have reliable and accurate liquid level measurements. Although based on a more traditional level measurement technology, one of the most trusted devices for continuous liquid level measurement remains the displacer level transmitter
The document discusses how improving instrumentation and level control in steam generation and condensate recovery systems can increase efficiency and reduce costs for industries that rely heavily on steam. Key areas that better level measurement can optimize include the boiler/steam drum, deaerator, feedwater heaters, blowdown flash tank, condensate receiver tanks, and heat exchangers. Technologies like guided wave radar that are unaffected by process conditions can provide more accurate level measurement and eliminate sources of error compared to differential pressure, buoyancy, or other inferential methods. This allows tighter control of levels throughout the steam cycle for maximum heat transfer, less blowdown waste, and recovery of more condensate for fuel and water savings.
Control Valves for the Power Generation Industry" A Product and Applications ...Belilove Company-Engineers
This document provides an overview of control valves for the power generation industry. It discusses the various systems in a conventional thermal power plant such as the condensate system, feedwater system, and main steam system. It then summarizes several case studies of Trimteck supplying control valves for applications in these systems for power plants. These include valves for condenser level control, boiler burner purge cycles, compressor reject control, turbine bypass, and superheater attemperation spray. The document promotes Trimteck as offering a full line of high quality control valves and solutions for flow control problems in power plants.
Society has benefited tremendously from the development and utilization of mechanical devices which are implanted inside the body and are used to replace bones and joints, increase blood flow, and even measure blood chemistry. To further enhance the performance of these devices, the application of thin films to the external surfaces is an ongoing research and development interest at many companies. Engineers have a choice of a variety of technologies to apply these liquid coatings to these often complex surfaces ranging from vacuum technology to direct liquid application. The decision on what technology to use is a function of the liquid precursor used, the mechanism of coating formation and the geometry of the object to be coated. A critical quality and process control criterion is the consistency of the coating on the surface. Fluid delivery technology can play an important part in maintaining coating consistency. Pumps and liquid flow controllers are technologies being used today. For vapor coating processes, liquid vaporization technology is a critical link in the fluid delivery system. New flow and vaporization technology is available that can be applied to fluid delivery to improve the application of medical device coatings.
An Intrinsically Safe Barrier is a device which limits the power (energy) which can be delivered from a safe area into a hazardous zone. Explosions are prevented; not just contained in explosion-proof conduit and housings. Not only is electrical energy (voltage and current) held within safe limits, but total energy is also contained, eliminating the possibility of an explosion due to excessive heat. Use of barriers and a total intrinsically safe design philosophy offers considerable advantages from cost and safety standpoints.
THE NEED
Equipment manufacturers and scientific researchers are continually challenged with supplying power, fiber-optic, control, and monitoring cables through sealed vacuum vessels. Whether due to space restrictions, special geometries, or number and type of conductors, standard glass-to-metal or ceramic feedthroughs never quite fit the bill. Unfortunately, because of limited options, many designers are forced to compromise and go for an off-the-shelf solution.
EPOXY TO THE RESCUE.
During the past decade, new epoxy compounds have been developed that rival glass and ceramic in performance. BCE is at the forefront of this development.
With modern epoxy feedthroughs, any kind of standard or custom connector is sealed in a completely potted, high-performance, clear epoxy compound. Epoxy seals offer countless design options, and most amazingly, performance equal to or better than glass or ceramic. Better yet, pricing is very competitive and quick turn-around for prototypes and short production runs are not a problem.
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Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
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TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEMHODECEDSIET
Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEM
Application of Combustion Analyzers in Safety Instrumented Systems
1. Application of Combustion Analyzers in
Safety Instrumented Systems
Larry E. Sieker, PE
AMETEK Process Instruments, USA
PRESENTED AT:
ISA Analysis Division
57th Annual Symposium
Anaheim, California, USA
April 2012
PROCESS INSTRUMENTSTHERMOX®
TechnicalPaper
www.ametekpi.com
2. 1
APPLICATION OF COMBUSTION ANALYZERS IN
SAFETY INSTRUMENTED SYSTEMS
Larry E. Sieker, PE
150 Freeport Road Pittsburgh, PA 15238
AMETEK Process Instruments
KEYWORDS
SIS, SIL, IEC 61511, API RP 556, O2
, CO break through, Methane, Zirconium Oxide, Catalytic
Bead, TDL
ABSTRACT
The combustion process has always been considered having the potential for a hazardous event
which could lead to personnel injury or loss of production. To mitigate this risk, the process
industry is now implementing Safety Instrumented Systems which can identify hazardous
operating conditions and correctly respond in such a way to bring the combustion process back
to a safe operating condition or implement an automatically controlled shutdown sequence
to reduce the risk of operator error causing a catastrophic event. Oxygen and combustible
flue gas analyzers are now being utilized in these combustion Safety Instrumented Systems
(SIS) to identify hazardous operating conditions and automatically return the process to a safe
state. The standards of IEC 61511 and API RP 556 will be reviewed as they apply to flue gas
analyzers, as well as the process variables of the oxygen and combustible analyzer available
for implementation into the SIS system for combustion monitoring, and the resultant actions
required to return the process to a safe condition.
4. 3
PROCESS INDUSTRY RISK
On March 23, 2005, a fire and explosion occurred at a Texas City refinery, killing 15 workers and
injuring 170 others. The refiner was charged with criminal violations of federal environmental
laws and has been subject to multiple lawsuits from the victim’s families. OSHA has since
slapped the refiner with a then-record fine for hundreds of safety violations, and subsequently,
imposed an even larger fine after claiming the refiner had failed to implement safety improvements
after the disaster.
Preventing process accidents requires vigilance. The passing of time without a process accident
is not necessarily an indication that all is well and may contribute to a dangerous and growing
sense of complacency. When people lose an appreciation for how safety systems were intended
to work, safety systems and controls can deteriorate, lessons can be forgotten, and hazards and
deviations from operating procedures can be accepted. Workers and supervisors can increasingly
rely on how things were done before, rather than relying on sound engineering principles and
necessary controls and safeguards. People can forget to be afraid.
Most all in the industry are aware of the potential hazards of firing and controlling combustion
processes. The idea of heating a hydrocarbon feed thru radiant and convective tubes to extreme
temperatures within a metal structure containing a “controlled” fire seems like an invitation to
disaster. Further, the variability in fuel quality, low emission burners, aged heaters and boilers,
and the desire to increase production thru the unit would seem to push the limits of proper
control and safety.
The realization that “incidents will happen” has led the refiner to implement safety systems
for combustion which are independent of the Basic Process Control System (BPCS) and will
identify hazardous operating situations and either take control of the process and shut it down
in a safe sequence or provide a permissive function to operations so that no further control
action can take place until the process returns to a safe state.
ThesesystemsimplementedforprocesssafetyarereferredtoasSafetyInstrumentedSystems(SIS).
STAANDARD IEC 61508 (International Electrotechnical Commission)
The current standard for Safety Instrumented Systems (SIS) is by the International Electrotechnical
Commission (IEC) and is detailed in IEC 61508 “Functional Safety of Electrical/ Electronic/
Programmable Electronic safety-related systems.” ANSI./ISA-84.00.01 was released in the
USA market and has since adopted IEC 61508 as the international standard.
This IEC 61508 standard was designed as an umbrella document that covers multiple applications
and industries and designed to be the “blue print” for the design standards of SIS. Released in the
5. 4
year 2000, it details the procedure of identifying process hazards and risks, identifying hardware
and software specification, commissioning, validating and documenting of the SIS process as
well as the eventual decommissioning of the SIS. A key part of this standard is that the design
of the SIS is by committee and not just an individual. All personnel from process engineering,
operations, environmental, validation, and maintenance are involved in the specification and
implementation of the system. This complete involvement of all plant disciplines insures that
all aspects of the process, its control, the potential hazards, required periodic validation, and
eventual decommissioning are addressed to insure maximum safety integrity. Once OSHAin the
United States stated that ISA 84.01 is “a recognized and generally accepted good engineering
practice for SIS”, the standard became accepted by many process companies in North America,
leading them to start implementing SIS for process risk reduction. When IEC 61508 passed for
the first time in February 2000,ANSI/ ISAadopted it as the international standard for functional
safety and a truly world standard was now recognized.
The Safety Life Cycle
The Safety Life Cycle (SLC) is one of the most fundamental concepts detailed in IEC 61508 and
ANSI/ISA 84.01. This common sense engineering procedure can be summarized in three steps:
1) Analyze the problem, 2) Design the solution, 3) Verify that the solution solves the problem
The problem analysis involves hazard identification and risk assessment. Potential indentified
hazards with enough risk may warrant the design of an SIS and the required safety level and
redundancy of measurement needed. Once a Safety Integrated Level (SIL) is assigned, a failure
probability calculation and risk reduction factor (RRF) calculation are done to verify that the
SIS design meets the risk reduction target. If the design does not meet the risk reduction goals,
better equipment can be chosen or redundancy of equipment can be employed to increase the
risk reduction.
THE SAFETY INSTRUMENTED FUNCTION AND THE SAFETY
INTEGRITY LEVEL
A Safety Instrumented Function (SIF) is defined as a “function to be implemented by a SIS
which is intended to achieve or maintain a safe state for the process, with respect to a specific
hazardous event”. A SIS can consist of one or many SIF functions and each SIF usually
incorporates one or more sensors for redundancy. During a “HazardAnalysis & RiskAssessment”,
the SIS committee will review the various control parameters in a particular SIF for a process
and determine each control loops potential to bring the process to a catastrophic state either by
control, final element, soft logic and/or operator failure, and is assigned a risk level, or “Safety
Instrumented Level” (SIL), which dictates the required equipment integrity and redundancy
6. 5
required to achieve the required SIS availability to mitigate a potential event. The basic factors
considered for determining the required SIL level are the potential severity of the event, the
frequency of the event occurring, and how much risk needs to be reduced to place the potential
event into an acceptable level of risk. This is typically a qualitative calculation of the Risk
Reduction Factor (RRF) expressed as follows:
Required Risk Reduction Factor = Mean Time between the Hazard/Demand Rate of the Event
An example would be a process heater where on average a burner flames out once a year,
flooding the firebox with high levels of carbon monoxide and methane which could cause the
heater to explode. Management has dictated that an explosion cannot be tolerated but once in
every 500 years. This would be then a Required Risk Reduction or a calculated RRF of 500.
Risk Level
IEC/ISA/AlChE
Safety Integrity
Level
Required Safety
Availability
Probability of Failure
on Demand
Risk
Reduction
Factor
(Note 1) 4 >99.99% <.0001 >10,000
High 3 99.9-99.99% .001-.0001 1,000-10,000
Medium 2 99-99.9% .01-.001 100-1,000
Low 1 90-99% .1-.01 10-100
Notes:
1. S il 4 is not used in the process industry. It is intended to representat other industries, such
as transportation, aerospace, or nuclear.
2. Field devices are included in the above performance specifications.
Table 1 Correlation between Overall Risk Level and Required Safety System Performance
Also considered in the SIL rating is the required safety availability and probability of failure
on demand. These are based on the field analyzers, final elements, and logic system specified
which have a determined probability of failure/ probability of operating properly if a hazardous
event happens. An SIS is invisible to the control operator. It stands in wait to function as
programmed and may not have to be utilized for years. The design of the system must take
into account the longevity and dependability of the equipment. Several manufacturers now
make available SIL certified equipment which have been reviewed and tested by a third party
agency to IEC 61508 and IEC 61511, and publish the failure rate data in as much the same way
as temperature specifications or accuracy figures, as well as having their equipment certified to
a specific SIL level. These SIL analyzer certifications tend to document the reliability and self
diagnostics available within the analyzer to insure reliable operation. In cases where third party
testing has not been completed, the user themselves can compile their own repair histories on
specific analyzers and instrumentation and compute their own failure rate data.
7. 6
STANDARD API RP 556
As with any combustion safety system, the proper and safe operation is dependent on an effective
control algorithm to monitor and identify potential harmful or catastrophic situations. Further,
the need to reduce risk in combustion processes throughout a company’s many locations dictate
that each site utilize the same proven control and safety standard to eliminate rouge, patched
or insufficient software. The API standard RP556, April 2011 “Instrumentation, Control, and
Protective Systems for Gas Fired Heaters” is currently being utilized in the United States for
process heater control and SIS installations. API RP556 provides guidelines that specifically
apply for gas fired heaters in petroleum production, refineries, petrochemical, and chemical
plants.
COMBUSTION ANALYZER
The combustion analyzer has been a necessary component of fired heater control for many
years. In its simplest form, the combustion analyzer provides an excess oxygen (O2
) reading
so that an air to fuel ratio can be maintained throughout the firing range of the process heater.
The analyzer is typically installed in the convective area of the process in close proximity to the
top of the radiant section so that the analyzer can provides a realistic value of how much extra
air was added to combust the fuel. This excess air set point is considered a “safety factor”, so
that by adding more air than required for complete combustion, operations can have a “control
cushion” so that if conditions change dramatically, the combustion process will not swing to a
“fuel rich” situation where fuel is not completely consumed and the potential for a hazardous
event could occur. Hazardous events created by a fuel rich situation would include burner
flame-out, carbon monoxide flood, black stack, convective section burning, slag formation, an
explosion, etc. In this regard, most refiners have opted to control with a higher than necessary
set point of O2
to insure a fuel rich situation is avoided. This insurance does have a price,
though. The high O2
set points for safety results in less efficient combustion, using more fuel
gas than necessary and higher NOx emissions.
Most refiners today realize the need to run process heaters at their lowest level of excess O2
to insure a complete burn of fuel for efficiency, and to reduce NOx without sacrificing safety.
Therefore, the combustion analyzer now used to control process heaters incorporates, besides the
excess O2
sensor, an additional sensor for “part per million” (ppm) “CO” or ppm “combustibles”
for feedback on the O2
set point. The combined O2
and CO combustion analyzer can provide
an output to control combustion air to a specific set point based on a specific firing rate and
then use the CO output as feedback on how effective the O2
set point is. An O2
set point with
no trace of CO in the combustion gas would mean that a lower O2
set point could be achieved
without affecting safety and reduce NOx emissions. An O2
set point with over 500 ppm CO
in the combustion gas would mean the O2
set point would need to be increased to completely
burn the fuel and avoid a potential combustion swing into a “fuel rich” operating area.
8. 7
SIS JUSTIFICATION
A large progressive US refiner had been using O2
and combustible analyzers for many years to
establish as low as an O2
combustion set point as they could achieve safely for efficiency and
emissions reductions by using the combustible reading as a fine tune adjustment to the primary
O2
set point. The use of combustible reading allowed them to slightly alter their operating O2
set
point to take into account variations of fuel quality, burner performance, and heat rate demand
and maintain maximum control quality and efficiency. However, tight control of a combustion
process does mean that unexpected deviations or upsets can get out of control quickly and in
the interest of safety, an independent system was needed beyond the level of process control
to insure that if a hazardous situation did occur, it could be dealt with so as to automatically
take control of the situation and respond in an appropriate way to bring the process back to a
safe level or achieve a proper shutdown sequence to minimize a hazardous result and insure
maximum safety. The typical operator response to large concentrations (or flooding) of CO or
combustibles in a process heater is to increase combustion air, which in most cases causes a
hazardous event.
The refiner’s hazard identification and risk assessment of their process heater events refinery-
wide revealed that there were only two major incidences where process heater safety was
compromised and shutdowns were common: 1) Heater light off / heater shutdown due to
methane accumulation, and 2) CO or combustible flood where there was a rapid accumulation
of partially burned combustibles whereas the control system and/or operator error performed
the wrong actions to diffuse the situation and resulted in a hazardous event.
The refiner decided to implement an SIS system independent of the BPCS for all process heaters
corporate wide as to insure that all process heaters are monitored by a safety instrumented
system that would take control of a hazardous event and insure that process safety interlocks
prevent any errors from the control system or operations that would bring the process back
into control or if needed, to provide an appropriate shutdown sequence to take place to bring
the process to a safe state.
Combustion analyzers incorporating oxygen, combustibles, and methane outputs were utilized
to provide the appropriate monitoring functions to implement the SIS functions required by
the API RP 559, Section 3.4.4.1 standard.
9. 8
API RP 559 3.4.4.1
ACCUMULATION OF COMBUSTIBLES WITHIN THE FIREBOX
(LOSS OF FLAME, SUBSTOICHIOMETRIC COMBUSTION, OR TUBE
LEAKS)
Potential hazards
The afterburning in the radiant, convection, or stack sections may result in the overheating and
failure of tubes, tube supports, and/or refractory systems.
An explosion may result with the partial or total destruction of the fired heater which may be
hazardous to the personnel in the operating area.
Considerations
At operating conditions, it is possible for a heater to accumulate combustibles at firebox
temperatures above the auto-ignition temperature if there is insufficient air to consume all of the
fuel. Fuel-rich combustion produces hot flue gas with residual combustibles that can explode
if mixed with fresh air too quickly. This is most likely to occur when a furnace transitions
suddenly from rich combustion to lean combustion.
At start up conditions, the accumulation of combustibles within the firebox should not be
permitted to exceed 25% of the lower explosion limit (LEL) before corrective action is initiated.
Excessively fuel lean combustion with low firebox temperature may lead to gradual accumulation
of combustibles within the firebox.
The following control overrides should be considered to keep the heater within operating limits
and prevent a heater shutdown:
• Low Oxygen override to the Fuel Controller - With the event of a low oxygen alarm,
the fuel gas controller is not permitted to increase fuel rate until oxygen is restored to
normal operating levels.
• High Combustible override to the Fuel Controller - With the event of combustibles
being over 500 ppm level, fuel gas flow must be decreased before combustion air can
increase.
10. 9
To mitigate the process hazards associated with the accumulation of combustibles in the firebox
and to prevent flame out, fuel gas valves should be closed in response to:
• Low or High Fuel gas Burner Pressure
• Low Draft (High Firebox Pressure)
• Failure of Stack Damper to Open
• High Liquid Level in Fuel Gas Drum
ANALYZER IMPLEMENTATION FOR SIS
The existing combustion analyzer used for process heater control could not be used in the
implementation of the safety system due to the inherent philosophy of SIS. If the combustion
control analyzer was used in the safety system and malfunctioned or failed, this would create
a situation is which the SIS system is designed to avoid. A completely independent system
from the BPCS is needed to monitor the process and bring it to a safe state or shutdown in a
controlled manner.
The SIF (Safety Instrumented Function) which incorporates the O2
and combustible analyzer
(measurement) was determined to be a SIL 2 Safety Integrity Level from the plant history of
the analyzer maintenance, calibration, and repair records. Further, due to flue gas stratification,
multiple burners, and the effective monitoring area of the convection section, it was determined
that multiple combustion analyzers were needed to provide a comprehensive measurement of
O2
, CO flood and/ or methane accumulation to insure an absolute response for control override
or shutdown. The amount of installed analyzers for the SIS system was determined by radiant
section area/ burner arrangement or by multiple combustion cells within one heater.
In most heater installations, this consisted of two analyzers mounted within 6 feet apart at
the same elevation, located at the bottom of the convection section, monitoring combustible
gases exiting the radiant section of the process heater. The O2
, CO, and methane readings of
each analyzer were compared with each other, as a diagnostic function, so that if any reading
deviated from each other within a certain tolerance, a “notice” alarm would be generated as
a diagnostic tool to insure the health of the SIS system and the accuracies of the analyzers.
These “deviation alarms” could not be set at the catalog accuracies of the combustion analyzer
sensors since the independent analyzers (sensors) were reading different flue gas locations.
Typical deviation alarms are 0.3% oxygen, 200 PPM combustibles, and 5000 PPM methane.
If a “notice” alarm was generated, a technician would be dispatched to determine if the analyzers
were function normally. The calibration frequencies of the combustion analyzers are usually
recommended as quarterly, yet there is a benefit to more frequent calibration. The “probability
of safety on demand” increases with more frequent calibration, which can reduce the required
SILneeded for the Safety Integrated Function that the combustion analyzer requires.An analyzer
11. 10
calibration frequency of monthly is typical.Aremote calibration function where the analyzer can
calibrate itself on a timed cycle allows independent verification without technician involvement.
To prohibit premature trips or false corrective actions from the SIS, the combustion analyzers
are configured in the safety logic as a 2oo2 or a 2oo3 voting scenario whereas either both have
to agree or two out of three agree to initiate the appropriate safety action, depending on the
number of analyzers installed. This insures that momentary stratification or analyzer malfunction
does not cause a non necessary corrective action.
COMBUSTION ANALYZER TECHNOLOGY
Close coupled extractive zirconium oxide (ZrO2
) based O2
analyzers are the analyzer of choice
for the SIS measurements. Typically installed for combustion control with fast response of
excess oxygen levels in hot dirty flue gas, their ability to measure near the radiant zone with
gas temperatures up to 2000F, and an established reliability record in the application, provides
the most reliable and accepted measurement for oxygen. ZrO2
sensors provide an extractive
“point type” measurement and are “net oxygen” analyzers which are heated and utilize platinum
electrodes with catalytic properties to determine oxygen concentrations of flue gas. They will,
however, burn any combustible compounds with oxidation potential such as hydrocarbons, CO,
hydrogen, and high concentrations of sulphur dioxide. During combustible flood conditions,
H2
and CO are the largest combustible components and they will consume oxygen in the flue
gas sample as they combust on the zirconium cell. The ratio of consumption of combustibles to
oxygen is 2:1, thereby, if 1000ppm combustibles is present in the flue gas, 500ppm of O2
will
be consumed from the flue gas sample. This decrease of the oxygen reading due to the burning
of combustibles is normally considered negligible. The operating principle of a zirconium oxide
sensor having to operate at 695 deg. C to function does create concern that the sensor could
cause combustible vapors to ignite on heater light off, shut down, or in a “non-operational
heater” outage state. Precautions are met by the installation of “flame arrestors” before and
after the measurement section of the analyzer to suppress any ignition as well as the possibility
of back-purging the sensor with instrument air to prevent vapors from entering the sensor, or
removal of sensor power in an outage situation.
The addition of catalytic bead type combustible sensors can be added to the close coupled
extractive analyzer O2
sample system to provide independent measurements of PPM combustibles
and percent levels of methane. These sensors, treated with a catalyst to allow combustible
compounds to burn on them at below ignition temperatures, are calibrated with combustible
gas they are designed to detect. The PPM combustible detector will respond to CO as well
as H2
, which both are normally present in fuel rich combustion when burning hydrocarbons,
and this reading is considered the feedback for O2
trim as well as the indication of a CO flood
condition. The methane detector is calibrated strictly for methane and is utilized as a permissive
12. 11
for a “Purge & Light Off” cycle to detect any methane present before the burners are lit. It
can be also utilized on shutdown where combustible fuel can accumulate as the process heater
begins to cool.
Recent advances in tunable diode laser (TDL) technology have made this analyzer a viable option
as well for installations in SIS for O2
and CO monitoring where a single point measurement
provided by close coupled extractive analyzers cannot provide a representative sample of flue
gas concentrations. Normally mounted in an across duct configuration, specific wavelengths
for O2
and CO can transmitted across the heater duct up to 100 feet to a detector mounted on
the other side looking for IR energy absorbance at the specific wavelengths of the specific gas
of interest. The larger the target gas concentration, the larger the IR absorbance is detected.
The installation of TDL analyzers usually requires two separate installations, one for O2
and
another for CO, since each need different lasers frequencies for detection. Recent advances will
provide the capability of incorporating two lasers in one enclosure for the ability of a dual gas
measurement. The location of installation is usually either across the radiant section or across
the top of the convection section due to the need to transmit across the heater with no internal
structures interfering with the IR transmission. TDL analyzers do provide a “duct average”
which can be useful in overall combustion performance and burner operation. Calibration or
verification of the TDL analyzer with calibration gas cannot be achieved due to the nature of
an “across the duct” type measurement. Units either have to be removed from the process for
bench calibration or the process can be “spiked” to insure the TDL analyzer responds.
DISCUSSION
The reliable identification of low combustion oxygen and a CO or combustible flood condition
in a process heater or fired process is critical to the effectiveness of a SIS system. The ability
of combustion analyzers to provide accurate readings quickly and have enough diagnostic and
verification capabilities insure performance when needed year after year should be paramount
to the decision of which type of measurement technology to choose.
Close coupled extractive O2
, combustible, and methane analyzers have years of installed plant
performance data to calculate mean time to failure as well as have established predictive
maintenance, calibration, verification, and repair procedures in place. Typical installations
in the bottom of the convection section are cost effective with one flange mounting for all
gases of interest in the SIS design. Close coupled analyzers can be challenged, verified or
calibrated automatically or on demand to insure optimum performance and availability. Yet,
this configuration does only provide a “point type” measurement and not a duct average, so
that stratification of gas flow concentration could be an issue. Furthermore, combustibles or
CO detection can be in the 20-30 second T90 response time do to the thermal detection of the
catalytic bead detector and the inherent delay of having flame arrestors in the detection flow loop.
13. 12
TDL analyzers can offer faster detection time in the 5 second T90 range and do provide an across
duct type measurement, which can be helpful in early detection of a CO flood condition. They
can be mounted in the hot, radiant section to provide measurement across the burner row and
do not need flame arrestors or aspiration air. TDL technology does lack the ability to challenge
the analyzer with calibration gas to insure proper operation and calibration, nor has much useful
data been made available for SIS failure and reliability calculations due to its minimal field
reliability history. The installations can be costly by having to cut through refractory on both
sides of the process and provide man-ways for both the detector and transmitter service access.
CONCLUSION
What is acceptable risk for catastrophic events when operating fired combustion processes in a
petrochemical complex? If there are 2000 process heaters or large boilers in the United States
and if only one had a catastrophic combustion event every year, a plant’s risk might only be
1 in 2000 per year. Is that acceptable if loss of life or environmental damage was the result?
What if the risk can be reduced to 1 in 2000 per 100 years? Even one large event in 50 years
could cause the federal government to step in to regulating industry safety or impose severe
monetary damages as recent disasters have shown.
It is obvious that the process industry needs to demonstrate a willingness to make plants as
safe as possible and reduce catastrophic events to an acceptable/ tolerable amount of risk. The
implementation of an SIS on the combustion process demonstrates industries investment into
plant and environmental safety, as well as documents their risk assessment and detailed plan for
catastrophic event prevention. If an event was to happen with a standardized SIS implementation
in place, who could argue that they did not do all they could do to reduce the risk of the event
and invested in an engineered risk reduction “as low as reasonably practical” for the safety
of their personnel, the community, and the environment? A Safety Integrated System for the
combustion process is a worthy investment.
14. 13
REFERENCES
BOOKS
1. Gruhn, Paul and Cheddie, Harry: Safety Shutdown Systems: Design, Analysis, and Justi-
fication. (ISA, 1998), ISBN 1-55617-665-1
2. Goble, William and Cheddie, Harry: Safety Instrumented Systems Verification: Practical
Probabilistic Calculations. (ISA, 2005), ISBN 1-55617-909-X
3. O’Brien, Chris and Bredemeyer, Lindsey: Final Elements: & the IEC 61508 and IEC
61511 Functional Safety Standards. (Exida, 2009), ISBN-13: 978-1-934977-01-9
REPORTS
1. Baker III, James Panel Chair: Baker Panel Report: The BP US Refineries Independent
Review Panel. (January 2007), http://www.bp.com/baker_panel_report.
2. Goble, Dr. William M: Safety Integrity Level Verification-Process and Problems. (Dec
2000).
STANDARDS
1. American Petroleum Institute: Instrumentation, Control, and Protective Systems for Gas
Fired Heaters. (April 2011), API Recommended Practice 556, second addition.