Process hazards analysis techniques

You can quickly identify these plant sections by reviewing process flow diagrams and valving arrangements. Isolation points are defined by control valves or powered block valves that can be remotely activated. Process hazard analysis techniques help you identify the maximum credible accident scenarios. (Note that manual valves should not be considered reliable isolation points unless they are located to be accessible following a major accident. However, remotely-activated valves can only be considered reliable isolation points if there are adequate reliability engineering and maintenance programs in place.)... 

In 1993, the Center for Chemical Process Safety (CCPS) published Guidelines for Safe Automation of Chemical Processes (referred to henceforth as Safe Automation). Safe Automation provides guidelines for the application of automation systems used to control and shut down chemical and petrochemical processes. The popularity of one of the hazard and risk analysis methods presented in Safe Automation led to the publication of the 2001 Concept Series book from CCPS, Layer of Protection Analysis A Simplified Risk Assessment Approach. This method builds upon traditional process hazards analysis techniques. It uses a semiquantitative approach to define the required performance for each identified protective system. 

The process hazards analysis is conducted by an experienced, multidisciplinary team that examines the process design, the plant equipment, operating procedures, and so on, using techniques such as... 

Process Hazard Analysis (PHA) An organized effort to identify and evaluate hazards associated with chemical processes and operations to enable their control. This review normally involves the use of qualitative techniques to identify and assess the significance of hazards. Conclusions and appropriate rec-... 

Deciding among a number of process options having inherent safety advantages and disadvantages with respect to different hazards can be quite difficult. The first step is to understand thoroughly all hazards associated with the process options. Process hazard analysis and evaluation techniques are appropriate tools (CCPS, 1992). These include ... 

While RP14C provides guidance on the need for process safety devices, it is desirable to perform a complete hazards analysis of tlie facility to identify hazards that are not necessarily detected or contained by process sLifety devices and that could lead to loss of containment of hydrocarbons or otherwise lead to fire, explosion, pollution, or injury to personnel. The industry consensus standard, American Petroleum Institute Recommended Practice 14J, Design and Hazards Analysis for Offshore Facilities (RP14J), provides guidance as to the use of various hazards analysis techniques. 

A number of hazard identification and analysis techniques (e.g., HAZOP), can be applied to identify, analyze, and reduce and/or mitigate the process hazards, which includes handling of reactive chemicals and energetic reactions. Chapter 4 provides an overview of these kinds of techniques as related to reactive chemicals mote detailed reviews of hazards analysis techniques are included in [2,3]. 

Process hazard analysis (PHA) Any of a number of techniques for understanding and managing the risk of a chemical process or plant. Examples of PHA techniques include HAZOP, checklists, what-if methods, fault tree analysis, event tree analysis, and others. 

Procedural controls, process controls, 98-99 Process controls, 96-100 active controls, 98 inherently safer approach, 97 mitigation techniques, 99 passive controls, 97-98 procedural controls, 98-99 safe operating limits, 99-100 Process definition, documentation, 102-104 Process design, documentation, 105 Process hazard analysis (PHA) risk assessment, 92-93 screening methods, 63 Process risk management decisions, documentation, 105-106... 

The process hazards analysis is conducted by an experienced, multidisciplinary team that examines the process design, plant equipment, operating procedures, and so on, using techniques such as hazard and operability studies (HAZOP), failure mode and effect analysis (FMEA), and others. The process hazards analysis recommends appropriate measures to reduce the risk, including (but not limited to) the safety interlocks to be implemented in the safety interlock system. 

The term operability study should more properly be used for this type of study, though it is usually referred to as a hazard and operability study, or HAZOP study. This can cause confusion with the term hazard analysis or process hazard analysis (PHA), which is a similar but somewhat less rigorous method. Numerous books have been written illustrating the use of HAZOP Those by Hyatt (2003), AIChE (2000), Taylor (2000), and Kletz (1999a) give comprehensive descriptions of the technique, with examples. 

Prior to stan-up of i production campaign, a process hazards analysis (PHA) should be conducted. A common and generally accepted PHA technique is the HAZOP (Hazard and Operability) method, although alternate teehniques can he equally effective 113.14,l.s, The purpose of the PHA is to evaluate the maiuiltictiiring prtteess to identity aiul address potential safely issues prior to start-up. 

Hazard analysis techniques shall be selected and used that are appropriate for the hazards and complexities of work processes being analyzed... 

The most widely used existing hazard analysis techniques were developed fifty years ago and have serious limitations in their applicability to today s more complex, software-intensive, sociotechnical systems. This chapter describes a new approach to hazard analysis, based on the STAMP causality model, called STPA (System-Theoretic Process Analysis). 

STPA (System-Theoretic Process Analysis) can be used at any stage of the system life qrcle. It has the same general goals as any hazard analysis technique accumulating information about how the behavioral safety constraints, which are derived from the system hazards, can be violated. Depending on when it is used, it provides the information and documentation necessary to ensure the safety constraints are... 

The team size will vary according to the nature of the process, the analysis technique, and the degree of experience of the individual team members. Figure 5.5 shows that the number of hazards identified will increase as the team size increases up to a certain point. Beyond that point, it is likely that adding more people will degrade the quality of the analysis because the discussion is more likely to be difficult to follow and control. 

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