Hazard operability analysis

Since clinical trials and toxicology studies require increasing amounts of product, an intermediate scale-up is often necessary. Scale-up may be performed in a pilot plant or in intermediate-sized laboratory equipment on-site or at a contract facility. As the scale increases, evaluation of the hazardousness of the operation sequence becomes necessary. Hazardous operation analysis may be done during this intermediate scale-up or during the detailed design. It is useful to take the results of the gap analysis and collect the appropriate data during intermediate scale-up. 

The Process Hazards Analysis team takes a systematic approach to identify potential process hazards and to document them [51]. The Hazardous-Operation Analysis (Haz-Op) is a method by which the process procedures, process and instrument diagrams, and process flow diagrams are evaluated for operability and safety. Fault-Tree Analysis (FTA) is also a method, which investigates the assessment of what-if scenarios and failure conditions. The outcomes of this analysis are recommendations for the col-... 

HSE assessments have a long tradition within the oil-and gas industry. These assessments use a wide range of methodologies, from the strict quantitative methods such as QRA (Quantitative Risk Analysis) and FMECA (Failure Mode Effect and Criticality Analysis) to the more qualitative methods such as HAZOP (HAZard OPerability analysis). Most methods combine qualitative and quantitative data and approaches. For example, an FMECA basically uses generic failure data, expert judgments are likewise important. 

Compare hazard operability analysis (HAZOP) with preliminary hazard analysis (PHA). 

Hazard and Operability Analysis. The hazard and operabihty analysis (HAZOP) procedure is quite popular because of its ease of use, the abihty to organize and stmcture the information, minimal dependence on the experience of the analysts, and the high level of results. Furthermore, the approach is capable of finding hazards associated with the operation of a faciUty, hence the incorporation of the word operabihty in the name. 

Recognized systematic approaches include hazard operability study (HAZOP) event tree analysis fault tree analysis. 

The analysis set out above demonstrates the importance of a comprehensive evaluation of the human aspects of a hazardous operation, from the point of view of identifying all contributory events and recovery possibilities. It also indicates the need for a complete evaluation of the operational conditions (procedures, training, manning levels, labeling, etc.) which could impact on these probabilities. 

Tliis particular case study does illustrate how event tree and fault tree analysis can be used in a hazard operability (HAZOP) study. 

New systems or processes may also need to be qualified from an operational safety perspective. This is particularly relevant in the case of chemical synthesis involving exothermic reactions. Critical safety aspects are usually identified using hazard operability or HAZOP assessments and studies. For example, a HAZOP analysis of an exothermic reaction vessel would involve consideration of the consequence of failure of the motors for mixers or circulation pumps for cooling water. Thus, the qualification of such a system would involve checks and assessment to ensure that the system/process can be operated safely and that pressure relief valves or other emergency measures are adequate and functional. 

MCA SD-99, 1973) HCS1980, 125 RSC Lab. Hazards Data Sheet No. 28, 1984 Piccinini, N. et al., Plant/Operations Progr., 1982, 1, 69-74 An operability analysis to identify potential risks in an allyl chloride manufacturing plant has been published. 

Another widely used safety analysis method in process industry is the Hazard and Operability Analysis, better known as Hazop (Kletz, 1992). The conventional Hazop is developed to identify probable process disturbances when complete process and instrumentation diagrams are available. Therefore it is not very applicable to conceptual process design. Kletz has also mentioned a Hazop of a flowsheet, which can be used in preliminary process design, but it is not widely used. More usable method in preliminary process design is PIIS (Edwards and Lawrence, 1993), which has been developed to select safe process routes. 

Hazard and Operability Analysis (Hazop) (Kletz, 1992) is one of the most used safety analysis methods in the process industry. It is one of the simplest approaches to hazard identification. Hazop involves a vessel to vessel and a pipe to pipe review of a plant. For each vessel and pipe the possible disturbances and their potential consequences are identified. Hazop is based on guide words such as no, more, less, reverse, other than, which should be asked for every pipe and vessel (Table 1). The intention of the quide words is to stimulate the imagination, and the method relies very much on the expertise of the persons performing the analysis. The idea behind the questions is that any disturbance in a chemical plant can be described in terms of physical state variables. Hazop can be used in different stages of process design but in restricted mode. A complete Hazop study requires final process plannings with flow sheets and PID s. 

Hazard and Operability Analysis (HAZOP) Identification of process disturbances with the quide words No, not more, less as well as part of reverse other than sooner, later other place... 

Hazard and operability analysis (HAZOP) A qualitative hazard analysis technique to identify and... 

If there is no hypothesis for the event, use an inductive method to find potential scenarios. Inductive methods speculate a given fault or failure, then look forward in time to determine the probable outcome, that is, What would happen if... Inductive methods include using a Checklist or a Hazard and Operability Analysis (HAZOP). 

Methods for performing hazard analysis and risk assessment include safety review, checklists, Dow Fire and Explosion Index, what-if analysis, hazard and operability analysis (HAZOP), failure modes and effects analysis (FMEA), fault tree analysis, and event tree analysis. Other methods are also available, but those given are used most often. 

Basically, it remains up to the design engineer and/or end user to determine whether and which type of SRV is to be used when doing a hazard and operability analysis (HAZOP). 

Identifying the potential hazards (PHA, process hazard analysis, or HAZOP, hazard and operability analysis) during operation must be done from a wide-angle approach dangerous situations can occur due to many root-cause situations other than those specified by, for instance, ASME or PED. Based on the results of the risk assessment, the pressure equipment can be correctly designed and the most effective safety system selected. 

Operational analysis comprises five tasks, the first of which is to identify and assess feasible hazard adjustments for the community and its households/ businesses. To accomplish this objective, EP coordinators... 

There are usually surprises when new processes are first tried. In view of the particular sensitivity of the chemical agent disposal program, the committee emphasizes the need for a hazardous operations (HAZOP) analysis for any new process (see Chapter 4). A HAZOP analysis by suitably trained people, and with input from operating people, could be particularly useful it might identify problems and at the same time warn the operating people about what to expect. 

A detailed safety assessment including persoimel hazard analysis (PHA), hazardous operations (HAZOP) and failure mode and effects analysis (FMEA) has been performed. 

---