A Correlation Method of Quality Problems and Process Safety for Improving Security Status of Chemical Production

The chemical process is always accompanied by a series of quality problems which are easy to cause accidents. Most of process safety incidents are caused by a series of quality problems. Quality problems play a very important role in the process of chemical production. However, compared with process safety incidents, quality problems did not receive strenuous investigation in some organization. If we can take some measures and pay more attention to quality problems in the daily process of chemical production, many process safety incidents may be avoided.

According to probabilistic principle and Swiss Cheese Model, the number of quality problems is consistent with the accident probability. A large number of quality problems are more likely to cause an accident. If the number of quality problems can be controlled, the accident probability may be controlled effectively. By the analysis of quality problems, an improved theory based on Process Safety Pyramid and Swiss Cheese Model is presented in the paper. The theory describes the relationship between quality problems and the risk level of no-impact or low-impact events and process safety incidents. Process safety quadrangle is put forward to explain the theory. In the theory, four risk levels are defined to show the security status of chemical production according to the number of quality problems.

On the basis of the theory, quality problems and process safety correlation method is put forward in the paper. In this method a checklist is used to investigate quality problems and determine the risk level of units. In order to apply the method to improve the security status of chemical production, several steps are included:

• preparation of quality problems checklist
• inspection of quality problems and the determining of risk level
• corrective action
• establish of data base

The method is applied to natural gas storage area briefly in this paper. The intent of the method is to improve the security status of chemical process and prevent occurrence of accidents. When the method is applied to the process of actual chemical production, some problems are discussed such as the division of risk level, table preparation, the determining of time interval and so on. The security status of chemical production can be improved effectively by using the method.

Keywords: quality problems, process safety, method, chemical production