Smith D.,Smith and Burgess
28th Center for Chemical Process Safety International Conference 2013, CCPS - Topical Conference at the 2013 AIChE Spring Meeting and 9th Global Congress on Process Safety | Year: 2013
Since around 2005, regulators in the United States have put greater emphasis on relief device installations meeting the 3% rule. Spending large amounts of money to "fix" relief device installations that pose no safety risk decreases the plant's overall safety. To date, more incidents have occurred during facility construction / modifications than due to relief device chatter. This paper presents a method to assist engineers in determining if relief devices are susceptible to chatter. The methodology in this paper provides an engineering study to determine if existing installations are safe, which are allowed in the relevant engineering standards (API STD 520), and shows the research data by which it was validated. The model is used as a screening method that places the relief devices into two categories: (1) those installations that may chatter and (2) those installations that need no further review. The goal of any experimental comparison is that the model will error on the side of predicting chatter, but will be reliable enough to screen valves. In addition to presenting the model, this paper will compare instances of known chatter to research conducted by API and work done by the Electric Power Research Institute in the 1980s. Thus far, based on research and acquired information, the method predicted all instances of chatter known to the authors. By providing a screening methodology that is supported by experimental data, plants can focus their spending on fixing real safety issues by identifying which relief installations are not expected to chatter. The paper will close by giving a brief explanation of the on-going research in relief valve stability.
Doe N.,Smith and Burgess |
Smith D.,Smith and Burgess
Process Safety Spotlights 2016 - Topical Conference at the 2016 AIChE Spring Meeting and 12th Global Congress on Process Safety | Year: 2016
The consequences associated with liquid overfilling are serious for plant safety, as illustrated by many recent incidents (2009, Bayamón, Puerto Rico; 2008, Chesapeake, VA; 2005 Hertfordshire, England; 2005 Texas City, Texas). In many cases, providing overpressure protection solely with pressure relief devices may not protect the facility. Preventing the uncontrolled release of liquid may be the only viable safe option. This paper will present an abbreviated analysis of several incidents that could have been avoided with proper preventive measures. Engineering methods will be presented to eliminate the need to release liquids from a closed system. For instance, the system can be designed such that upstream pressure sources are limited below the allowable downstream pressure. A designer can provide a safety instrumented system with an appropriate Safety Integrity Level (SIL) rating to reduce or eliminate the credibility of overfilling. Alternatively, consideration may be taken for alarms and operator response, with consideration for RAGAGEP, to reduce the credibility of overfilling to an acceptable risk. Systems can be redesigned to be inherently safer by minimizing contained liquids. This paper then gives a few examples of the use of system design, shutdown systems, alarms/operator response combination and inventory controls to eliminate or reduce the potential for liquid release scenarios.
Burgess J.,Smith and Burgess
AIChE Ethylene Producers Conference Proceedings | Year: 2014
Sizing pressure relief valves is a complex process for any chemical or petrochemical; however, relief devices in Ethylene, Propylene, and Ethane service can raise some unique concerns. One concern is how the chemicals' physical properties affect the operating conditions. Chemical processes of Ethane, Ethylene, and Propylene are frequently operating in thermodynamic supercritical conditions because the chemicals' temperatures and critical pressures are low. Operating in thermodynamic supercritical conditions makes it even more imperative that the engineer ensures accurate physical properties are used in the analysis. Another unique concern is the cryogenic processing conditions of these chemicals, which makes it challenging to meet material and brittle fracture hazards. The last unique concern is the decomposition of these chemicals when at elevated pressure. All three chemicals, but especially Ethylene, can decompose upon rapid depressurization from pressure greater than 4000 psig.This paper is a brief analysis of these special considerations and how they could potentially affect a relief systems design.
Wakil W.,Smith and Burgess |
Bruner T.,Smith and Burgess
50th Annual Loss Prevention Symposium 2016, LPS 2016 - Topical Conference at the 2016 AIChE Spring Meeting and 12th Global Congress on Process Safety | Year: 2016
Most young engineers experience a defining moment or moments in their career that shape their attitude towards importance of Process Safety Management (PSM). Experiencing a plant upset first-hand knowing that there were actual capital or human life impacts or both from an incident at the site, one soon realizes early in their engineering career why process safety is so important. It becomes evident that the most successful corporations are those who are willing to invest large capital costs into PSM documentation projects or projects that have come as a result of findings identified during a study, allowing them to prevent incidents from occurring. The findings generated during the course of a study may result in simple documentation update action items, or they may require a multi-million dollar investment. For young engineers, this exposure puts into perspective the value of their work, and emphasizes the importance of a thorough and adequate study. © 2016, Smith & Burgess, LLC.
White J.,Smith and Burgess |
Spearow J.,Smith and Burgess
AIChE 2013 - 2013 AIChE Spring Meeting and 9th Global Congress on Process Safety, Conference Proceedings | Year: 2013
Heat integration is a common practice in process optimization, and it is becoming more and more important in the oil, gas, and petrochemical industry. This optimization often involves increases in process throughput. Two examples were presented, where evaluating the effects of heat integration on the relief systems prevented costly modifications to those systems. The first case involves a refinery investigating the implementation of a heat integration project in their crude fractionation. The second case involves a refinery working to resolve some concerns pertaining to the radiation levels identified previously for the controlling flare scenario (total power failure). The two case studies demonstrated that examining the limitations of the system does not require significant time or rigorous modeling software. A relatively simple steady state analysis can be performed that captures the limitations of the systems and still provides a conservative result that does not take any credit for positive control. By simply understanding how heat is conserved in the process, numerous engineering hours and countless dollars can be saved. This is an abstract of a paper presented at the 2013 AIChE Spring Meeting & 9th Global Congress on Process Safety (San Antonio, TX 4/28-5/2/2013).
Stein A.,Smith and Burgess |
White J.,Smith and Burgess
AIChE Annual Meeting, Conference Proceedings | Year: 2013
The foundation of one's profession can have an exponential effect on the lifelong development of their careers. There may be no stronger launching point than the lessons learned as a young engineer specializing in process safety. A young engineer building a foundation on process safety may have the opportunity to work on and visit a magnitude of different processes and environments. One may also see similar processes operated in different manners. However, a vast range of exposure is not the only valuable material in the development of a career. In a relatively short period of time, one specializing in process safety can learn to understand how safety can sometimes become an afterthought for many process engineers. This can ultimately lead to costly or even life-threatening consequences that must be addressed reactively. With a foundation in process safety, one is of the mindset to address safety issues in a proactive manner, and thus ultimately becoming a more efficient engineer.
Rozmus G.,Smith and Burgess |
Smith D.J.,Smith and Burgess |
Baum D.A.,Smith and Burgess
Process Safety Progress | Year: 2014
Greater numbers of action items are being generated from the Layer of Protection Analysis (LOPA) process as it becomes increasingly utilized as a method for risk evaluation. The quantity and type of action items result from the combination of initiating events, conditional modifiers, and prescribed guidelines. The quality of the inputs determines whether the action items will actually provide any additional safety benefit. This article is not a procedure for performing a LOPA analysis but presents issues to be aware of when generating a list of initiating events, evaluation of the initiating event severities, and the influence of conditional modifiers. © 2013 American Institute of Chemical Engineers.