HAZOP (HAZARD & OPERABILITY STUDY)
HAZOP Study means “Hazard and Operability Study”. It is a risk assessment technique which adopts a systematic way to identify possible hazards in a work process. To carry out the HAZOP study, the process is broken down into simpler sections called nodes and the nodes are individually reviewed; every variation in work parameters is considered for each node, to see what could go wrong
The aim of the HAZOP study is to find potential situations that could cause the element in a process to pose a hazard or limit the operability of the process as a whole.
What are the benefits of conducting HAZOP Study?
A HAZOP is used as a final check on a sound engineering design and should not be used as an element of a design review for an operating facility. HAZOPs are used in a wide range of industries, including Oil & Gas, Mining & Minerals, and Pharmaceuticals, to name a few. In order to effectively run a HAZOP process, a multidisciplinary team is required to ensure that a diversity of knowledge and experience is used to identify the credible risks.
When HAZOP should be done?
HAZOP analysis can be performed during different stage of a system lifecycle.
HAZOP is usually carried out once final P&IDs from the design team are available. The diagrams are subjected to questioning with the use of proper guidewords and visualizing possible failure modes. Before undertaking HAZOP of a new facility, it is essential that the latest design considerations during the design review stages are already incorporated in the P&IDs and other documents.
Approach / Methodology
A HAZOP is a structured brainstorming meeting, involving multi-disciplinary team, set up to identify potential undesirable events that may create hazards or operability problems, i.e. risks to personal safety and potential damage to assets, the environment and the reputation. The identified hazards, along with any actions for further investigation and other relevant, supporting information are recorded on HAZOP worksheets.
The information & the documents/ P & IDs to be used for a HAZOP study, should be the latest one authenticated for HAZOP study and display accurate information. Fol-lowing basic assumptions are made before initiation of HAZOP study-Assembly of a team of experienced project personnel
- HAZOP Studies assume that all the design criteria have been met & design is not challenged unless obvious error is identified.
- All subsequent in-house modifications have been engineered using best engineering practice and international standards.
- Purpose of HAZOP Study is not to discover the design flaws.
The HAZOP process is best understood if divided into the following steps:
- Identifying a section of plant on the P&I diagram and divide them in nodes;
- Define the node’s design intent and process conditions;
- Apply the first/next parameter (i.e. flow, pressure, temperature etc.);
- Apply the first/next guide word, which when combined with the parameter will give the deviation;
- Determine (by brainstorming) all the potential causes of the deviation;
- Agree the credibility of each cause;
- Assess the consequences of each cause;
- Assess the protection/ safeguards provided against the causes and its consequences;
- Evaluate the likelihood of the net effect of consequence and protection (using risk ranking matrix);
- Agree a recommendation for action or further consideration of the problem;
- Apply the next guide word (relevant to the selected parameter);
- Apply the next parameter until they have all been considered; and
- Move onto the next node of the system until the whole study has been examined.
This team will include:
- Design consultant / Project Manager
- Production Manager
- Chemical engineer / Chemist
- Maintenance Manager
- Electrical Engineer
- Instrument Engineer
- Quality Control Engineer
- HSE Representative, etc.
Within the team, a lead facilitator should be nominated to lead the study. The lead facilitator should be a competent and experienced person in the conduct of the HAZID study.
The overall methodology for the HAZOP workshop is depicted in below Figure.
Figure: HAZOP Methodology
Other information needed when identifying hazards are:
- Information about the hazards present or likely to be present in the workplace.
- Information from conduct of initial and periodic workplace inspections of the workplace to identify new or recurring hazards.
- Information from incident investigation.
- Information from trend analysis
- Information from the severity and likelihood analysis of incidents that could result for each hazard identified, and use this information to prioritize corrective actions.
Backup documents for effective hazard identification
Some important documents are good source of information when carrying out hazard identification.
These documents may be internal documents or external documents.
The software to be used for the HAZOP study is PHA PRO
PHA-Pro is designed based on corporate-wide risk policies and programs into place and aid in the adoption of Process Safety Management (PSM) programs under OSHA 26 CFR 1910.119, EPA Risk Management Program, Seveso II Directive, Control of Major Accident Hazards (COMAH), IEC 61511, ANSI/ISA S84.00.01-2004 standards and regulations. It helps in building customizable worksheets and forms of existing templates, as well as brand new templates, enabling the user to adapt to a variety of safety and reliability methodologies. The software is characterized by advanced professional reporting.
The HAZOP Study report will contain, as a minimum, the following sections:
- Executive Summary
- Scope of the study
- Study methodology
- HAZOP findings and summary of recommendations
- HAZOP Team Attendance Sheet
- HAZOP Worksheets
iFluids Engineering helps to provide the right solution and necessary recommendation with results for the precise decision for your HAZOP studies…