ICEweb has nearly 100 Control, Instrumentation, Fire & Gas, Safety Instrumented Systems core pages and a total of more than 300 pages - It Really is Cool Engineering - By Engineers for Engineers it must be just about the World's first choice for Technical Information.
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Whilst every effort is made to ensure technical accuracy of the information supplied on iceweb.com.au, Keyfleet Pty Ltd and its employees accept no liability for any loss or damage caused by error or omission from the data supplied. Users should make and rely on their own independent inquiries. By accessing the site users accept this condition.
Posted by: Jim Russell, August 2015
A Practical Guide to Improving Temperature Measurement Accuracy - Gary Prentice - For many temperature applications, getting a high level of accuracy is vital. “A Practical Guide to Improving Temperature Measurement Accuracy” highlights how plant and site engineers can ensure the most accurate temperature measurement for critical applications. This article details steps that can also help end users improve the stability of their measurements and reduce calibration costs - from our sponsor Moore Industries.
Extracting HART Data from Smart Instruments - According to the FieldComm Group (formerly the HART Communications Foundation), there are more than 30 million HART-enabled instruments installed in chemical and process plants worldwide, and most process transmitters made today are HART compatible. The HART digital signal often contains valuable process measurements and other variables including instrument status, diagnostic data, alarms, calibration values and alert messages. However, many systems fail to utilize the critical information available from HART-enabled transmitters, valve positioners, flowmeters and other "smart" devices. This article from our sponsor Moore Industries shows how a HART interface device can serve as a simple and cost-effective solution for gathering HART information.
Posted by: Jim Russell, June/July 2015
Thanks to ICEweb Sponsor Zedflo the Test and Calibration Instrumentation pages have been updated
Temperature Compensation Really Matters for Pressure Measurement
Guide to Testing and Tagging Portable Electrical Equipment and Residual Current Devices at Workplaces - As prescribed by the Occupational Safety and Health Regulations 1996 (the OSH regulations), the person having control of a workplace or access to that workplace, i.e. Employer, self-employed person, main contractor, must ensure that all portable plug-in electrical equipment and residual current devices (RCDs) at the workplace are safe and appropriately inspected, tested and maintained by a competent person. This document will assist with regulatory compliance by providing guidance on who can inspect and/or ‘test and tag’ such portable equipment and devices - from Worksafe WA.
Instruments and Testers - This Technical Catalogue covers Electrical
Installation Safety , High Voltage Insulation / Continuity / Earth, Appliance /
Machine / Switchboard Safety, Power Quality Analysis , LAN Cabling
Certification, Indoor Environment Quality,ƒ Digital Multimeters / Clamp
Meters / Voltage and Continuity Testers, Variable transformers / Equipment for
laboratories and Schools – from METREL
The following calibration white papers are from Additel Corporation
Calibrating Differential Pressure Sensors – How to calibrate a DP sensor and understand some of the calibration challenges associated with them.
Calibrating a Pressure Switch - Pressure switches are commonly used in the process industry for a wide range of applications. A pressure switch is a form of sensor that closes or opens an electrical contact when a certain pressure has been obtained either through a pressure rise or a pressure drop. Pressure switches are used to monitor, control, or provide a caution or warning for a pressure related process. The repeatability, accuracy, and functionality of a pressure switch often tie directly into the safety or efficiency of a process and thus it becomes important that pressure switches are verified and calibrated to ensure their proper function in the process.
Considerations for Hydraulic Pressure Calibrations - Jon Sanders - If you are doing high pressure, hydraulic calibrations there are a few things that you'll need to consider which will make your life a little easier and help you produce stable measurements. This application note focuses on considerations for pressure calibrations using a high pressure hydraulic pump to generate the pressure.
Improved Methods for High Pressure Pneumatic Calibrations in the Field - Jon Sanders - Are you tired of dragging a nitrogen bottle and dead weight tester out to the field to perform pneumatic high pressure calibrations? Does it trouble you to use a hydraulic pump or dead weight tester for your gas gauges every time you have to go above 600 psi? This application note details the limitations to traditional methods and provides a solution to calibration of gas gauges up to 3,000 psi (200 bar) with a field-ready calibration tool.
Accuracy Specifications for Digital Pressure Sensors – Percentage of
Full Scale Versus Percentage of Reading - Jon Sanders - Specifications for
digital pressure gauges can sometimes seem confusing or overwhelming,
especially, if you are unfamiliar with the terminology. Some pressure sensors
will specify accuracy as a percent of full scale (FS) while others provide the
specification as a percent of reading. So why are there different ways of
specifying the accuracy of pressure sensors and is percent of reading more
accurate than percent of full scale or vise versa? This brief technical note
will discuss the two differences and answer these questions.
Thanks to ICEweb Sponsor Zedflo our comprehensive Ultrasonic Flowmetering page has been updated.
Calibrating Ultrasonic Gas Meters - Joel Clancy - The primary method for
custody transfer measurement has traditionally been orifice metering. While this
method has been a good form of measurement, technology has driven the demand for
a new, more effective form of fiscal measurement. Ultrasonic flowmeters have
gained popularity in recent years and have become the standard for large volume
custody transfer applications for a variety of reasons. Most users require flow
calibrations to improve meter performance and overall measurement uncertainty.
The latest revision of AGA Report No. 9, Measurement of Gas by Multipath
Ultrasonic Meters, Second Addition [Ref 1], now requires flow calibration for
ultrasonic flow meters when being used for custody transfer applications. What
considerations then, should be taken when choosing to flow calibrate an
ultrasonic flowmeter? What are the benefits to the user? What should a user
expect from a flow calibration? What kind of performance should the customer
expect or accept from an ultrasonic meter? What are the diagnostic capabilities
inherent in an ultrasonic meter? These areas, as well as others will be explored
and considered - from CRT Services.
Liquid Ultrasonic Meters - Christopher B. Laird - Proving is the process
that determines the accuracy of a meter. A prover is a device with detector
switches that define a precise, known volume. The prover is connected in series
with the meter being proved so that as flow passes through the meter, the same
flow, and only that flow must pass through the prover. The flow moves the
displacer in the prover until it touches the first detector switch, the pulses
coming from the meter start being counted by a prover counter. When the
displacer touches the second detector switch, the pulses from the meter stop
being counted. In this way, the exact number of pulses generated by the meter
for an exact amount of flow is determined and the actual volume registration of
the meter can be compared to the known volume of the prover. The ratio of the
volume of the prover to the volume registered by the meter is called the Meter
Factor. The proving process involves taking the average of several tests
(comparisons) of the above mentioned ratio and checking the consistency of the
tests. For example, if 5 tests or proving runs are made, the ratios must agree
within 0.05%. If they do, then statistically, the uncertainty of the average
Meter Factor will be within 0.027% and will meet industry requirements - from
Applications in Liquid Measurement Using Clamp-On Ultrasonic Technology - Sid Douglass - Ultrasonic meters are typically used to measure flow and clamp-on ultrasonic meters are no exception. One will find these meters installed in most aspects of the petroleum industry. This white paper details some of these applications - from CRT services.
Posted by: Jim Russell, May 2015
Thanks to Prochem Pipeline Products ICEweb's Instrument Fitting and tubing pages have been updated.
Fittings and Small Bore Tubing Systems - Handbook - This superb 72 page document from the Norwegian Oil and Gas Association covers most engineering aspects of small bore tubing and fittings.
and Tube Fittings - This open source book Lessons in
Industrial Instrumentation by Tony R. Kuphaldt has a useful section on
instrument connections has a useful section on Instrument Tube Fittings – go
to page 573. This is a fantastic resource but be prepared for the 50Mbit
Document on Instrumentation Tubing and their Connections - Nirbhay Gupta
- Instrumentation tubing covers both Impulse tubes (sensing lines) as well as
pneumatic tubes. Connections include tapping points, root valves and tube
fittings. Usually one has to refer to a myriad of technical documents, codes and
standards to search for a specific aspect of tubing design or construction. This
technical note is an attempt to put all the information at one place. The
efforts have been put to expose the readers to all the aspects of tubing and
make them aware of all the developments in the world.
Winterization Solutions for the Power Industry - In the power industry, winterization often presents a set of engineering, design and installation details that can fall to the bottom of a project priority list. Poor coordination of these details can result in a freeze up, which can cost millions in lost revenue and additional expense. High process temperatures combined with sub-freezing ambient conditions requires industry expertise in design and installation of winterizing systems. - from obcorp.
Co-Planer Instrument Manifolds - This technical engineering note from Rosemount gives a good description of the advantages and benefits of these manifolds.
Matching Valve Type to Function - A Tutorial in Valve Selection - Michael D Adkins - In selecting valves for instrumentation, the choices are many and varied. The choice depends mostly on the application the valve is to be used for. When selecting a valve for an instrumentation system, your choices may seem overwhelming. Just to name a few, there are ball valves, diaphragm and bellows valves, as well as check valves, excess flow valves, fine metering, gate, multiport, needle, plug, relief, rising plug and safety valves. Further, each of these valves comes in many sizes, configurations, materials of construction and actuation modes. To make the best choice, it is always good practice to ask the first question in valve selection: what do I want the valve to do? From www.processonline.com.au
2186:2007 - Fluid flow in closed conduits - Connections for pressure signal
transmissions between primary and secondary elements – This standard sets out
provisions for the design, lay-out and installation of a pressure signal
transmission system, whereby a pressure signal from a primary fluid flow device
can be transmitted by known techniques to a secondary device safely and in such
a way that the value of the signal is not distorted or modified.
Valve Fail Action - Frederick Meier and Clifford Meier - Control valves may fail in various positions -open, closed, locked, or indeterminate. The position of a failed valve can have a significant impact on associated equipment, and therefore, it is of interest to operations personnel - from the ISA and InTech.
Posted by: Jim Russell, April 2015
Thanks to our sponsor Powerflo Solutions Pty Ltd ICEweb's Comprehensive Pressure Relief Valve page has been updated extensively and now includes the following links;
Relief Valve Maintenance - This
is what you should expect from your repair facility – Alton Cox - Pressurized
systems are protected from catastrophe by safety measures including preventive
maintenance. The most important piece of equipment in a pressurized system, the
pressure relief valve (PRV), is the one piece of hardware that must always be
ready to operate properly when needed. However, the PRV also is the one piece of
equipment we hope never needs to operate. Because the PRV is the last line of
defense against a catastrophic failure of a pressurized system, it must be
maintained in “like new” condition if it is to provide the confidence
necessary to operate a pressurized system - from Plant Services.
of Safety Relief Valves – This Technical
Resource from LESER provides a collection of documents for repairing or
maintaining safety valves. The following topics are covered; Maintenance
Fundamentals of safety valves, Repair process, Suggested equipment for
assembling, disassembling and rework of critical parts, Disassembly, including
sectional drawings, Rework of critical parts including an overview of critical
dimensions, Assembly, including options, Spring charts, Testing procedures (set
pressure and leak tests), Spare parts lists, Guidelines for inspection, storage
and transport and Trouble shooting.
Prediction of Two-Phase Choked-Flow through Safety Valves - G Arnulfo, C Bertani and M De Salve - Different models of two-phase choked flow through safety valves are applied in order to evaluate their capabilities of prediction in different thermal-hydraulic conditions. Experimental data available in the literature for two-phase fluid and subcooled liquid upstream the safety valve have been compared with the models predictions. Both flashing flows and nonflashing flows of liquid and incondensable gases have been considered. The present paper shows that for flashing flows good predictions are obtained by using the two-phase valve discharge coefficient defined by Lenzing and multiplying it by the critical flow rate in an ideal nozzle evaluated by either Omega Method or the Homogeneous Non-equilibrium Direct Integration. In case of non-flashing flows of water and air, Leung/Darby formulation of the two-phase valve discharge coefficient together with the Omega Method is more suitable to the prediction of flow rate - from IOP Science.
Relief-Valve Sizing Requires Equation Mastery - JS Kim,HJ Dunsheath, NR Singh - This article is related to the sizing of relief valves for
two phase flow.
Best Practices in Pressure Relief Valve Maintenance and Repair - Kate Kunkel - Information about maintenance and repair programs for pressure-relief valves. This article covers the various types and functions of PRVs and defining their physical characteristics, Donalson and Simmons along with codes and standards covering PRVs - from Valve Magazine.
Relief Valve Engineering - The purpose of this amazing
resource from Leser Valves is to
help understand the “world of safety valves”. Specifically, it explains:
- What is a safety valve
- The applications in which safety valves are used
- How a safety valve is installed
- How to size and select a safety valve
- The global standards and requirements which apply to safety valves
This Technical Engineering Book is intended to be a knowledge resource for the occasional user as well as the advanced user of safety valves. It covers; History and Basic Function, Design Fundamentals, Terminology, Codes and Standards, Function, Setting and Tightness, Installation and Plant Design, Sizing, Selection, Materials, Connections, Quality and Environmental Management, Markings, Approvals, Shipping, Handling and Storage, LESER USPs , Frequently Asked questions and Trouble Shooting. It is a large download but worth it!
Relief Devices Requirements - The scope of this document
applies to manufacture, assembly, selection & sizing, inspections, repairs,
servicing, setting & sealing and installation of Pressure Relief Devices in
Alberta, Canada. This document covers; Definitions & Acronyms used in this
document, Certificate of Authorization Requirements,
Overview of The Act, Regulations, Codes And Standards, Scope of
Alberta’s Bench Testing Program, Pressure Relief Devices Manufacturing,
Assembling, Selection And Sizing, Installation, Operation, In-Service
Inspections Requirements and Servicing Intervals, Pressure Relief Devices Design
Registration Requirements and Quality Management System Requirements – Whilst
being targeted at Alberta Canada this document provides some very useful
information – from ABSA.
Pressure Relief Valve Engineering Handbook - Whilst specific for Anderson Greenwood, Crosby and Varec products this manual this document has some useful information. It has been designed to provide reference data and technical recommendations based on over 125 years of pioneering research, development, design, manufacture and application of pressure relief valves. Sufficient data is supplied so that an individual will be able to use this manual as an effective aid to properly size and select pressure relief devices for specific applications. Information covering terminology, standards, codes, basic design, sizing and selection are presented in an easy to use format – from Pentair
Thanks to our sponsor Powerflo Solutions Pty Ltd ICEweb's Comprehensive Level Page has been updated extensively and now includes the following links;
Comparison of Recommendations for Overfill Prevention - The Buncefield
Report (MIIB) & API RP 2350 - Back in 2005, there was a dangerous accident
that occurred at the Buncefield Oil Depot, which was the largest fire in Europe
since World War II. This fire was caused by an overfill of an outdoor storage
tank, causing a release of a flammable vapour that was ignited. The overfill
safety system for Tank 912 in bund A failed to operate and shut off the supply
of petrol to the tank. When API 2350 was released, it was based on the events of
the Buncefield Oil Depot overfill back in 2005. Both API and the MIIB (Major
Incident Investigation Board) released new revisions and reports respectively to
their standards after reflecting on what went wrong at Buncefield. API RP 2350
was released in 2012 and helped establish good practices. The Buncefield final
report was released in 2008 and helped lay out recommended practices for
primary, secondary and tertiary containment of a potential overfill situation.
These recommended practices covered a wide range of overfill prevention areas
from having systematic assessments of SIL requirements to creating a culture
where high performance and leadership are expected. The Buncefield reports and
API 2350 cover very similar topics relating to overfill prevention - thanks
to our sponsors Powerflo Solutions
Pty Ltd and Magnetrol.
Interface Level Measurement - Five leading interface measurement
technologies in use today are discussed in this technical bulletin. Grouped by
their operating technologies, these include Buoyancy (Floats and Displacers), RF
Capacitance, Thermal Dispersion, Radar, and Redundant Technologies (those
combining two measurement technologies in one instrument) - from Powerflo
Solutions Pty Ltd and Magnetrol.
of New Level Technologies in Single Use, Disposable Systems - David
Ladoski and Dan Klees - This article presents guided wave radar level
measurement as an acceptable, less expensive alternate to load cell systems.
Foam Measurement Within Liquid Process Media is a Challenging Application
- Process media susceptible to foaming are particularly challenging to accurate
liquid level measurement. Foam’s lower density, as compared to a foam-free
liquid, will absorb or deflect a substantial portion of the return signal,
diminishing the all-important reflectivity required by non-contact measurement
Standards of Level Control Devices - Malfunctioning level controls
allegedly contributed to the 1986 Chernobyl meltdown and the 2005 Buncefield
depot explosion north of London, to name just two of the more notorious
incidents. For decades, the industrial firewall against safety incidents as they
relate to level controls has been governmental and professional association
standards that require manufacturers to make their products according to safety
guidelines. The International Standards Association, however, lists some 180,000
varieties of international standards. The key health and safety standards that
can affect level control devices and applications fall into three categories:
(1) Instrument and Component Standards, (2) Safety Integrity Levels, and (3)
A Practical Overview of Level Measurement Technologies - Martin Bahner - There are multiple technologies available on the market to measure level. Each and every technology works, when applied properly. This presentation discusses the strengths and weaknesses of RF Admittance, Capacitance, Ultrasonic, Radar, Nuclear, Differential Pressure, and Bubblers level measurement technologies - from Gilson Engineering Sales.
Posted by: Jim Russell, March 2015
Thanks to our sponsor McCrometer ICEwebs V-Cone Flowmetering page has been updated extensively and now includes the following links;
VM V-Cone System Flow Meter - Measurement Simplified -
This bulletin covers Performance, Accuracy, Self-conditions flow, Maximum
installation flexibility, Maintenance and Features and Benefits of V-Cone
Disturbance Cone Meter Testing - Gordon Stobie, Richard
Steven, Kim Lewis, Bob Peebles - Cone meters have grown in popularity due to
their claimed immunity to flow disturbances. Cone meters are said to require no
flow conditioning and little upstream and downstream straight pipe lengths. If
this is true, cone meters can be installed in many locations where no other flow
meter could operate satisfactorily. A meter that is immune to flow disturbances
is of significant importance to industry. Hence, independent proof of cone meter
resistance to flow disturbances is important. However, there is little
literature in the public domain discussing cone meter performance in disturbed
flows - The Norwegian Society for Oil and Gas Measurement.
Flow Meter Improves Efficiency and Reduces Costs in Gas Lift Applications (Ideal
for Low Pressure Oil / Gas Production Sites) - Nick Voss
- Process engineers responsible for crude oil production from wells that employ
gas lift systems to increase oil production will find that the rugged, highly
accurate V-Cone® Flow Meter from McCrometer features a wide turndown, small
footprint and virtually no maintenance, which reduces total installed costs and
operating life cycle costs while improving crude oil production efficiency.
of Wet Gas Measurement Equipment for Fiscal Allocation -
Dr Max Rowe, Rod Bisset, Anthony Alexander - Item 2 on the index of papers -
When a new field is to be accepted by a host, it is necessary to define a
functional specification for the measurement equipment. This is usually
documented as part of the allocation agreement. The question that needs to be
addressed is: “What is an acceptable measurement specification?”. The
ultimate answer will be one which meets standards set by relevant Government
authorities and is acceptable to all parties who approve the allocation
agreement. One approach, often used, is to apply standard guidelines derived
from industry best practice, e.g. 1% uncertainty for a gas fiscal flow
measurement. This approach has the advantage of being simple to apply, but may
involve some measurements being made with an unnecessary degree of accuracy.
Another approach is to undertake modelling of uncertainty in the measurement
system to establish the criticality of each measurement. Scheers and Wolff point
out the need to consider the whole measurement system through to allocated
revenue and propose that the optimum uncertainty of each measurement should be
established by evaluating the trade-off between measurement costs and the losses
and risks of uncertainty in the measurement. In this paper an extension of these
approaches is applied in which uncertainty modelling was applied to the
propagation of uncertainty through the whole measurement and allocation system
and was used to establish the impact on each company or field’s revenue stream
- The Norwegian Society for Oil and Gas Measurement
ICEweb's Safety Instrumented Systems (SIS) page is seen by an average of 320 engineers per month sponsorship of this page can be yours at VERY reasonable rates - Contact ICEweb here for details
The Safety Instrumented Systems page has been updated with numerous new links including:
Management of Functional Safety - Gaps in the Operation Phase - Andy Yam - According to the IEC 61511 standard, the purpose of having a Functional Safety Management (FSM) system during the safety lifecycle is to identify the management activities that are necessary to ensure that the functional safety objectives of the safety instrumented system are met. These activities are separate from the health and safety measures in the workplace. As per the safety lifecycle model in this standard, management of functional safety is a requirement throughout the lifecycle of the plant, including during the conceptual, implementation and operational phases. In the ensuing years after the release of the functional safety standards, a lot of emphasis has been placed on meeting the requirements during the conceptual and implementation phases. However, it is equally important that the Safety Instrumented System (SIS) is operated and maintained in compliance with the standards, especially considering that plants typically are operated for up to 30 years as compared to the Conceptual and Realization Phases, which may last a couple of years. This paper looks at some common gaps in operation and the strategies and activities required for compliance - from the IDC Safety Control Systems Conference 2015
Safety and Ageing Assets - Shane Higgins and Lyn Fernie
– HIMA Australia - When designing a new facility, functional safety standards
can be adopted at relatively low cost in order to reduce risks as low as
reasonably practicable (ALARP), provided that standards are correctly specified
and adopted from the earliest stages of a project. Practical ways to implement
the standards for ageing assets are not immediately evident. The question often
arises whether an existing plant or installation should be expected to comply
with the same base standards as new assets. The functional safety standards
provide a mechanism to determine an integrity requirement for a safety-related
system based on the risk posed by hazardous scenarios. To enable a decision as
to whether a retrofit is reasonably practicable, it is necessary to consider all
the available options, assess the reduction in risk (benefit) provided by any
new or modified safety functions/systems, and weigh that up against the cost of
such improvements - from the IDC Safety Control Systems Conference
Functional Safety and Ageing Assets - Shane Higgins and Lyn Fernie – HIMA Australia - When designing a new facility, functional safety standards can be adopted at relatively low cost in order to reduce risks as low as reasonably practicable (ALARP), provided that standards are correctly specified and adopted from the earliest stages of a project. Practical ways to implement the standards for ageing assets are not immediately evident. The question often arises whether an existing plant or installation should be expected to comply with the same base standards as new assets. The functional safety standards provide a mechanism to determine an integrity requirement for a safety-related system based on the risk posed by hazardous scenarios. To enable a decision as to whether a retrofit is reasonably practicable, it is necessary to consider all the available options, assess the reduction in risk (benefit) provided by any new or modified safety functions/systems, and weigh that up against the cost of such improvements - from the IDC Safety Control Systems Conference
Generally Accepted Good Practice Approach to Functional Safety Management - David
Nassehi- Senior Functional Safety Engineer, CFSE, PMP-
Plexal Group - The Project Management Institute (PMI) Project Management Body of
Knowledge (PMBOK) GUIDE (ANSI/PMI99-001-2008/IEEE1490-2011) presents a set of
standard guidelines for project management and identifies the project management
body of knowledge that is generally recognized as good practice. It is
process-based and the approach is consistent with ISO 9000. It describes the
project management life cycle and the project life cycle. This paper compares AS
IEC-61511 lifecycle and Functional Safety Management requirements with the PMBOK
guidelines, identifies the approaches which are in line with both and suggests
strategies to embed in the project lifecycle which improves Functional Safety
(FS) objectives throughout the safety lifecycle to achieve integrated functional
safety and project management - from the IDC Safety Control Systems Conference
Safety Instrumented Function: An S-Word worth Knowing - Understand the SIF to
Control Confusion, Complexity and Cost of Safety Instrumented Systems - William
L. (Bill) Mostia Jr - The term "safety instrumented function"
or SIF is becoming common in the world of safety instrumented systems (SISs). It
is one of the increasing number of S-words--SIS, SIL, SRS, SLC, etc.--that are
coming into our safety system terminology. The definition of a SIF as provided
in IEC standard 61511, "Functional safety: Safety Instrumented Systems for
the process industry sector," leaves a bit to be desired as a practical
definition, and the application of the term leaves many people confused - from
or SFAIRP, or Reasonably Practicable - What does it mean and how do you meet the
Requirements? - Shane Daniel
– This paper covers; Requirements for reducing risk, How to demonstrate ALARP,
Balance, Analysing and Quantifying the Cost, Implementation, Regulatory
Requirements, Performance Standards Evaluation, Critical factors for success - from
the IDC Safety Control Systems Conference 2015
Achieving Compliance in Hardware Fault Tolerance - Mirek Generowicz FS Senior Expert (TÜV Rheinland #183/12) - Engineering Manager, I&E Systems Pty Ltd - The functional safety standards ISA S84/IEC 61511 and IEC 61508 both set out requirements for ‘hardware fault tolerance’ or ‘architectural constraints’. The method specified in ISA S84 and IEC 61511 for assessing hardware fault tolerance has often proven to be impracticable for SIL 3 in the process sector. Many users in the process sector have not been able to comply fully with the requirements. Further confusion has been created because there are many SIL certificates in circulation that are undeniably incorrect and misleading. This paper describes common problems and misunderstandings in assessing hardware fault tolerance. The 2010 edition of IEC 61508 brought in a new and much simpler and more practicable method for assessing hardware fault tolerance. The method is called Route 2H. This paper explains how Route 2H overcomes the problems with the earlier methods. The proposed new edition of IEC 61511 will be based on Route 2H - from the IDC Safety Control Systems Conference 2015.
Allocation of Client and Contractor Responsibilities for AS 61508 Safety
Lifecycle Activities - Mike Dean - Principal
Engineer/Director, EUC Engineering Pty Ltd - Correct allocation of activities
and deliverables related to the safety lifecycle of AS 61508 between a client
(end-user) and contractor is crucial to achieving success for a project
targeting AS 61508 compliance. Too often end-users establish specifications and
scopes of work with the stated intention for the contractor to carry out all of
the activities and providing all of the deliverables of overall safety lifecycle
phases 1 to 13, without appreciation of their own key role. End-users need to
understand their own legal obligations and the intent of AS 61508 for
establishing overall safety requirements. This paper proposes an allocation of
responsibilities which achieves legal and AS 61508 compliance - from the IDC
Safety Control Systems Conference 2015
Could it be Considered “Good Engineering Practice” to Bypass your SIS during
the Most Critical Time of Your Process? - Luis M. Garcia
G. CFSE - Siemens Energy & Automation - Although most facilities embrace
ANSI/ISA 84.00.01-2004 (IEC 61511) and the Safety Life Cycle (SLC) as the way to
comply with regulatory requirements (Like OSHA 1910.119), there are specific
instances when most operations deviate from the standard. These are during
start-up, shut-downs and process transitions. Processes with adequately designed
Safety Instrumented Functions (SIF) that are validated to well developed Safety
Requirement Specifications (SRS) are commonly (although momentarily) idled, and
instead are practically replaced by a team of operators, managers and
specialized personnel. Bypassing, inhibiting or masking is a common practice
during these plant conditions. In these cases, the Safety Instrumented System
(SIS) is temporarily replaced by humans in calculated and intensely watched
conditions. This paper questions the need for this practice and confronts the
practical limitations that lead to it. It examines the assumptions used to
justify the suspension of certain SIFs and uses Burner Management Standards and
typical process SIS, as an example of how to automate the permissive sequencing
required for these process change of states. Finally, the paper examines how a
cause and effect tool could be used to simplify the development and
implementation of automated permissive sequences including verification and
validation as required in the standard - from the IDC Safety Control Systems
Impact of Bypassing and Imperfect Testing on Safety Instrumented System
Performance - Paul Gruhn, P.E., ISA 84 Expert Global
Process Safety Consultant, Rockwell Automation - Bypassing and imperfect manual
testing have historically been ignored in safety system modelling, yet the
impact of both is quite easy to model, and the negative performance impact is
much greater than many people realize. In fact, one of many recurring causes of
chemical plant accidents has been documented as “inadequate indications of
process condition”, of which at least one case consisted of operations
continuing when a safety instrument was in bypass. The second edition of IEC
61511 about to be released now acknowledges dangerous failures not detected by
automatic diagnostics or manual testing. This paper summarises how these two
factors can be modelled and their dramatic impact on system performance - from
the IDC Safety Control Systems Conference 2015
Optimizing Component Arrangement in Complex SIS - A Case Study - Hamid Jahanian, Senior Engineer, Siemens Ltd - The arrangement of components plays a key role in the performance of complex Safety Instrumented Systems (SIS) in which a SIS logic solver is interlocked with other logic solvers, to share a final element, for instance. The position of components and the way they are utilized affects the reliability characteristics, such as the Probability of Failure on Demand (PFD), Spurious Trip Rate (STR), architectural sensitivity and model uncertainty. A real-life example is presented in this article to highlight the impact of component arrangement. The case study uses quantitative and qualitative analysis to review two SIS architecture solutions in a renovation project where the existing turbine protection system is upgraded to incorporate a new over-speed protection system. Also, a classification for SIS components based on their response to demand is introduced, and a set of guidelines for SIS architecture engineering is developed - from the IDC Safety Control Systems Conference 2015
to Functional Safety Standards in Gas Detection - Preeju
Anirudhan - Draeger Safety Pacific Pty Ltd - The objective of this session is to
create awareness on gas detection and the various technologies used in gas
detection, including the role of gas detectors in risk reduction. This paper
covers gas dispersion & placement of sensors and the considerations that
must be given while deciding sensor technology, sensor placement and maintenance
of the detectors, with a life-cycle approach. It also discusses the various
standards applicable in the field of gas detection, functional safety
applications, including standards applicable to plants & projects. In
addition it addresses common mistakes due to incorrect use of standards,
controller and precautions that must be taken while using PLC’s and the
limitations of using PLC’s for gas detection applications - from the IDC
Safety Control Systems Conference 2015
Posted by: Jim Russell, February 2015
Posted by: Jim Russell, January 2015
The Hazards Associated with Combustible Dust - The hazards associated with the storage and handling of combustible dusts is often overlooked in comparison to those associated with flammable liquids and vapours. Indeed the risks associated with flammable liquids and vapours are generally well understood and appropriate control systems are in place to prevent releases and their ignition. In comparison, although many are aware of the possibility of explosions occurring from combustible dust, the controls implemented are rarely adequate - from Risk Tech
The Shutdown and Blowdown Valve page has been completely upgraded - this must be the best resource in the world for this subject!
ATEX Questions and Answers - This Technical Information sheet from Control and Instrumentation covers ATEX, ATEX Directive, What ATEX applies to, Product Compliance and Marking.
Armoured Cable Glands – Covers; Reasons for using Cable Glands, Standard for Cable glands, Selection of Cable Glands, Barrier Glands and Gland Sizing - from Control and Instrumentation.
Posted by: Jim Russell, November 2014
for an Electrical Preventive Maintenance (EPM) Program - The purpose of this
standard is to provide recommended practices and frequencies that would form the
core of a regularly scheduled electrical preventive maintenance program. There
is a useful section on maintenance of enclosures – from Hartford
Outdoor Equipment Enclosures Simplify Instrumentation Installations in Ultra-Cold Environments – These enclosures provide a versatile alternative to free-standing cabinets for the environmental protection of field-based process instrumentation. Developed at the request of a Russian oil refinery, the enclosures are made from tough glass reinforced polyester (GRP) and include highly insulated options for use in extremely cold climates. They also offer more space than typical instrument enclosures, to allow plant personnel to use gloved hands when accessing the equipment. Typical applications include housing differential pressure flowmeters and process transmitters in refineries, petrochemical and chemical processing plants - from Intertek
Passive Fire Shelters Enhance Safety Management for Offshore Gas Project -
Fabricated using lightweight composite GRP (glass reinforced polyester)
materials, these shelters employ patented techniques to resist fire for two
hours – allowing critical electronic safety equipment to remain operational.
Although there are currently no standards for this application area that cover
containment temperatures, Intertec designs, manufactures and tests its fire
shelters to a rigorous proprietary specification which demands that their
internal temperature must remain below 60 degrees C throughout the rated
protection time. The novel shelters are also capable of withstanding both
conventional and more severe hydrocarbon fires - from Intertek.
Cabinets Protect Sample Conditioning and Process Analyzer Instrumentation on
World’s Largest Vessel - Much of the on-line process analysis
instrumentation on the Prelude FLNG vessel will be housed in purpose-built
environmental protection cabinets. The cabinets are required to be capable
of withstanding severe Category 5 tropical cyclones with wind speeds in
excess of 252 km/h (157 mph) and to have a minimum service life of 25 years
- with 50 years as a design aim. Additional requirements include a high
degree of resistance to corrosion being caused by the saline environment and
the presence of sour or acid gas, and the ability to cool electronics
equipment without using explosion-proof air conditioning systems, which
incur high capital and operating costs - from Intertec
Protection Shelter Employs Passive Cooling to Meet Challenges of Middle East Gas
Project - One of the largest passively-cooled instrumentation shelters ever
constructed is being supplied by Intertec to house remote control and
instrumentation equipment required for a new natural gas collection project in
the Middle East. Without any electricity, the cooling system reduces interior
shelter temperatures by some 20 degrees Celsius – to enable the
instrumentation to operate at its desert location - from Intertec
Cooling Oil Drilling Electronics in Class 1, Division 2 Environments – Details on a cost-effective air conditioning solution for enclosures to be used to protect electronics in drilling rig equipment - from EIC Solutions Inc
Safe Enclosures for Rough Seas - Sturdy Distribution Enclosures Defy the Harsh Environmental Conditions - Details on marine applications enclosures which have a corrosion resistant surface, absolute seal and Ex approval
Enclosures and Cable Glands - This useful technical catalogue from Weidmüller covers the specification and requirements of enclosures which are often used in harsh environments. They remain reliable for many years thanks to the high quality levels, even when exposed to external influences like water, dust, hard impacts, shock, vibration, corrosion, and extreme temperature fluctuations. All components used in potentially explosive atmospheres are subject to strict safety regulations and are checked to the finest detail in terms of their functionality as well as their resistance and resilience against the prevailing environmental conditions. As each enclosure is only as strong as its weakest point, it is ensured that each individual component is of the highest quality and that it will not therefore cause a weak point in the enclosure. This is a large download but jut about provides all the information required for Enclosures and other Accessories.
Posted by: Jim Russell, October 2014
Cable Drum Handling - A Cable is a valuable product. If handling is not done correctly, the drum and in turn the Cable wound over it can be damaged. At times, damage might not be discovered until after installation, when repairs can be extremely difficult / expensive. The purpose of this guide is to illustrate, how damages can be avoided by correct handling and storage practices - from Gulfcable
Drum Schedule - Comprehensive Learning Guide - Drum scheduling is a logical process of putting together pieces of cables to make a spool of cable. Procurement of cables is generally transacted in unit of drum. During construction stage, the lay out (pulling) of cables are drawn out and cut from the drums. For these reasons, proper drum management is necessary to facilitate the procurement processes and to maximize the usage of the cable in the drums - from ELTECHS Engineering & Consulting Co., Ltd.
in Low Voltage Systems - Covers Earthing
connections, Definition of standardised earthing schemes, Characteristics of
TT, TN and IT systems, Selection criteria for the TT, TN and IT systems,
Choice of earthing method – implementation and Installation and
measurements of earth electrodes - from Schneider Electric
Earthing Systems - This excellent link from Wikipedia,
the free encyclopedia
Posted by: Jim Russell, September 2014
Electrical Resistance Temperature Sensor (RTDs and Thermistors) - Kamal Siddique - This report gives a brief description of Electrical Resistance Sensors for the measurement of temperature. The main focus of this report is on “Resistance Temperature Detectors RTDs” and “Thermistors”. The main body of the report includes definition, working principle, construction, different types, wiring configuration, advantages and disadvantages of RTD and Thermistor. All these topics have been explained in such a way that their role in process industries for the measurement of temperature, probably the most important variable in process industries, becomes crystal clear and their selection by a process engineer for a specific duty becomes easier - from Engineering Resource.
WWAN - Expanded Wireless Connectivity - More than 60% of manufacturers have the need for intrinsically safe devices within hazardous environments like oil & gas and the chemical and pharmaceutical industries. this webinar details mobile solutions, merging safety with performance where there are opportunities to help grow your profits - Thanks to our sponsor TRANSTEK and ECOM Mobile Safety.
Mobile Solutions for Hazardous Environments -This webinar details the basics of explosion protection and then covers potential benefits which can be achieved by deploying mobile computing solutions in hazardous areas to achieve a Return on Investment or RoI - Thanks to our sponsor TRANSTEK and ECOM Mobile Safety.
How Can You Manufacture Explosion-Proof Equipment and Systems to World-Class Safety Requirements? - Depending upon the Zone of usage, electrical, electronic and mechancial equipment intended for use in potentially hazardous environments must be independently evaluated for their impact on overall safety. The European Union’s ATEX Directive and the IECEx Certified Product Scheme are two assessment routes used for the safety of equipment used in such environments. This white paper provides an overview of these two routes and provides answers to frequently asked questions. You will have to register to download this paper from TÜV SÜD .
Industrial Temperature Measurement - Basics and Practice - This absolutely fantastic 280 page technical engineering resource from ABB is just about the best document of its type. Well done to the authors.