Application of Functional Safety Analysis in Refined Oil Station
195
3 Steps of HAZOP-LOPA
(1) Preparation
Determining the analysis scope; collection data; preparing implementation plan;
determining team members; making meeting record form, etc.
(2) Performing HAZOP analysis
Dividing the analysis scope into nodes; describing design intent of target node; calculating the deviation; analyzing the consequences caused by deviation; finding the reasons for the deviation; making a list of the existing safety protection measures; risk level
assessment; proposal of suggestions and measures; analyzing and recording; repeating
the whole procedures of performing HAZOP analysis for other nodes respectively.
(3) Perform LOPA analysis
Picking up the accident scenes exposed to high risk according to the results of
HAZOP analysis, determining the occurrence probability of initial event, conditional
event and consequential event; calculating the frequency of remaining events; identifying
the existing independent protective layers and safety protection measures, and meanwhile
determining their failure probabilities; calculating the frequencies of events relieved;
determining the risk after being relieved and evaluating whether it can be accepted or
not; based on the evaluation, judging whether additional measures are needed, if yes,
proposing relevant suggestions [16].
(4) Writing the HAZOP-LOPA analysis report accordingly.
4 Case Study
HAZOP-LOPA analysis method is applied to evaluating the initial station of a longdistance products oil pipeline. The normal operation of this station is divided into 8
nodes for analysis, such as transferring the oil transported to the station into the oil
tanks at the tank farm (OIT); transporting the oil in oil tanks outside; transferring the
oil between tanks; launching chamber; discharging pollution, etc. Through HAZOP
analysis, 191 existing or potential problems are found, and 278 suggestions are proposed.
While through LOPA analysis, 15 detailed suggestions are given. Taking the high oil
level deviation in the process of OIT for example, the application of HAZOP-LOPA
analysis method in the products oil station is illustrated.
As with the large deviation of the oil level in the tank, the reasons and the occurrence
probability are analyzed. The consequences the deviation may cause and the seriousness
of the consequences are listed in a table. Then the existing protection measures are found
out. After that the residual risk level is determined and corresponding suggestions are
proposed. The matrix describing the risk level is shown by Table 1, while part of the
HAZOP analysis results are shown in Table 2.
195
3 Steps of HAZOP-LOPA
(1) Preparation
Determining the analysis scope; collection data; preparing implementation plan;
determining team members; making meeting record form, etc.
(2) Performing HAZOP analysis
Dividing the analysis scope into nodes; describing design intent of target node; calculating the deviation; analyzing the consequences caused by deviation; finding the reasons for the deviation; making a list of the existing safety protection measures; risk level
assessment; proposal of suggestions and measures; analyzing and recording; repeating
the whole procedures of performing HAZOP analysis for other nodes respectively.
(3) Perform LOPA analysis
Picking up the accident scenes exposed to high risk according to the results of
HAZOP analysis, determining the occurrence probability of initial event, conditional
event and consequential event; calculating the frequency of remaining events; identifying
the existing independent protective layers and safety protection measures, and meanwhile
determining their failure probabilities; calculating the frequencies of events relieved;
determining the risk after being relieved and evaluating whether it can be accepted or
not; based on the evaluation, judging whether additional measures are needed, if yes,
proposing relevant suggestions [16].
(4) Writing the HAZOP-LOPA analysis report accordingly.
4 Case Study
HAZOP-LOPA analysis method is applied to evaluating the initial station of a longdistance products oil pipeline. The normal operation of this station is divided into 8
nodes for analysis, such as transferring the oil transported to the station into the oil
tanks at the tank farm (OIT); transporting the oil in oil tanks outside; transferring the
oil between tanks; launching chamber; discharging pollution, etc. Through HAZOP
analysis, 191 existing or potential problems are found, and 278 suggestions are proposed.
While through LOPA analysis, 15 detailed suggestions are given. Taking the high oil
level deviation in the process of OIT for example, the application of HAZOP-LOPA
analysis method in the products oil station is illustrated.
As with the large deviation of the oil level in the tank, the reasons and the occurrence
probability are analyzed. The consequences the deviation may cause and the seriousness
of the consequences are listed in a table. Then the existing protection measures are found
out. After that the residual risk level is determined and corresponding suggestions are
proposed. The matrix describing the risk level is shown by Table 1, while part of the
HAZOP analysis results are shown in Table 2.