HAZOP.pptx

Hazop

1. Ha z ard and Operabi l i t y ( HAZOP) St udy 1

2. HAZOP ? - Definition? - Background? Where HAZOP is used ? Seven Steps of HAZOP study? Contents ? 2

3. A SCENARIO….  You and your f riends are on a road trip by using a car in the middle of the night. You were replying a text message while driving at 100 km/h and it was raining heavily. The car hits a deep hole and one of your tire blows. You hit the brake, but due to slippery road and your car tire thread was thin, the car skidded and was thrown off the road. 3

4. POINTS TO PONDER What is the cause of the accident? What is the consequence of the event? What can we do to prevent all those things to happen in the first place? What other possible accidents might happen on the road trip? Can we be prepared before the accident occurs? 4

5. Can we make it more systematic? Parameter Guideword Possible Causes Consequences Action Safeguard Car speed Too fast Too slow Rushing Skidded when emergency brake Slow down Speed up -ABS brake system -Safety belt - Air bag Tire No thread Less thread Tire too old, often speeding and emergency break Car skidded Check frequently Have spare tire Window visibility Low Very low Rain Cannot see the road Car light Dim No light -Stop car -Go to nearest garage -Use emergency signal Road With holes Rocky Breaks the car tire - Put a signboard -Street lights Travel time Night Foggy No street light -Travel during daylight 5

6. HAZ OP ?  A Hazard and Operability (HAZOP) study is a structured and systematic examination of a planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel or equipment, or prevent efficient operation.  A HAZOP is a qualitative technique based on guide-words and is carried out by a HAZOP team during a set of meetings.  A HAZOP is a process to identify and Access risks . 6

7. Objective of HAZOP 7 For identifying cause and the consequences of perceived mal operations of equipment and associated operator interfaces in the context of the complete system. It accommodates the status of recognized design standards and codes of practice but rightly questions the relevance of these in specific circumstances where hazards may remain undetected.

8. HAZ OP ? 8

9. RISK ? 9

10. HAZOP team and meetings

11. HAZ OP ? 10

12. Team Members & Their Responsibility HAZOP team leader HAZOP secretary HAZOP team members Responsibilities: Responsibilities: The basic team for a 1.Define the scope for the 1.Prepare HAZOP process plant will be: analysis 2.Select HAZOP team members worksheets 2.Record the discussion in the HAZOP meetings Project engineer Commissioning manager Process engineer Instrument/electrical 3.Plan and prepare the 3.Prepare draft report(s) engineer o Safety engineer study 4.Chair the HAZOP meetings

13. HAZOP meeting Proposed agenda: Introduction and presentation of participants. Overall presentation of the system/operation to be analysed. Description of the HAZOP approach. Presentation of the first node or logical part of the operation. Analyse the first node/part using the guide-words and parameters. Continue presentation and analysis (steps 4 and 5) Coarse summary of findings. Focus should be on potential hazards as well as potential operational problems. Each session of the HAZOP meeting should not exceed two hours. 7

14. Types of HAZOP Process HAZOP: Human HAZOP : Procedure HAZOP: Software HAZOP : Indrajit Das;REC;IIT-KGP 14

15. HAZOP procedure • • • • • • • • • • • Divide the system into sections (i.e., reactor, storage) Choose a study node (i.e., line, vessel, pump, operating instruction) Describe the design intent Select a process parameter Apply a guide-word Determine cause(s) Evaluate consequences/problems Recommend action: What? When? Who? Record information Repeat procedure (from step 2) Indrajit Das;REC;IIT-KGP 15

16. Causes & Consequences Causes: The reason(s) why the deviation could occur. Several causes may be identified for one deviation. It is often recommended to start with the causes that may result in the worst possible consequence. Consequences: The results of the deviation, in case it occurs. Consequences may both comprise process hazards and operability problems, like plant shut-down or reduced quality of the product. Several consequences may follow from one cause and, in turn, one consequence can have several causes . 17

17. Sa f e g u a r ds Facilities that help to reduce the occurrence frequency of the deviation or to mitigate its consequences. There are five types of safeguards that: Identify the deviation: Compensate for the deviation: Prevent the deviation from occurring: Prevent further escalation of the deviation: Relieve the process from the hazardous deviation.

18. HAZOP technique is used by most major companies handling and processing hazardous material, oil and gas production flammable and toxic chemicals pharmaceuticals etc Where HAZ OP is used ? 11

19. 7 steps of HAZ OP ? Let’s break down a HAZOP into 7 steps: Identify the Risk by asking what can cause a hazardous event. Describe the consequence and assign a severity level. Assess the probability of the cause. Evaluate the Risk based on the severity and probability without any safeguards Look up your Risk Matrix to categorize the Risk. Assess the Risk with Safeguards Make a decision to accept the Risk or make a recommendation to further reduce the risk. 12

20. G UI D E W O RD S * POSSIBLE CAUSES DEVIATION ( FROM DESIGN AND/OR OPERATING INTENT ) CONSEQUENCES ACTION(S) REQUIRED OR RECOMMENDEED HAZOP Study Procedure 21

21. Guide Words 22 NONE MORE No forward flow when there should be More of any parameter than there should be, e .g m o r e f l ow , m o r e p r e ss ure, m o re temperature, etc. LE S S P A R T MORE THAN O T H E R As above, but "less of" in each instance S ys t em c o m po s i t i o n d i ff e r e n ce f r o m wha t it should be More "components" present than there should be for example, extra phase, impurities W h a t n ee ds t o h a p p e n ot he r t h a n n o r m a l operation, e.g . start up,shutdown, maintenance

22. Guide Words 23 MORE OF LESS OF LE SS PART OF MORE TEMPERATURE , pressure caused by external fires; blockage ; shot spots; loss of control ; foaming; gas release; reaction;explosion; valve closed; loss of level in heater; sun. e.g ., LESS FLOW caused by pump failure; leak; scale in delivery; partial blockage ; sediments ; poor suction head; process turndown. e.g ., low temperature, pressure caused by Heat loss; vaporisation ; ambient conditions; rain ; imbalance of input and output ; sealing ; blocked vent . Change in composition high or low concentration of mixture; additional reactions in reactor or other location ; feed change.

23. Guide Words Impurities or extra phase Ingress of contaminants such as air, water, lube oils; corrosion products; presence of other process materials due to internal leakage ; failure of isolation ; start-up features. Activities other than normal operation start-up and shutdown of plant ; testing and inspection ; sampling ; maintenance; activating catalyst; removing blockage or scale ; corrosion; process emergency ; safety procedures activated ; failure of power, fuel, steam , air, water or inert gas; emissions and lack of compatibility with other emission and effluents. 24 MORE THAN O T H ER

24. HAZOP Study Form 28 Sheet 1 of HAZOP STUDY REPORT FORM TITLE : LINE 1 : C A U S ES DEVIATION C ON S EQUEN C E S EXISTING PROVISIONS ACTIONS, QUESTIONS OR RECOMMENDATIONS

25. HAZOP Study 29 HAZOP study are applied during : Normal operation Foreseeable changes in operation, e.g. upgrading, reduced output, plant start-up and shut-down Suitability of plant materials, equipment and instrumentation Provision for failure of plant services, e. g . steam, electricity, cooling water Provision for maintenance.

26. 30 M a n a g i n g H A Z O P How to manage HAZOP

27. Prel i mi nary HAZOP Exampl e 31 T C Cooling Coils M o n o me r Feed Cooling Water to Sewer Cooling Water In Thermocouple Refer to reactor system shown. The reaction is exothermic. A cooling system is provided to remove the excess energy of reaction. In the event of cooling function is lost, the temperature of reactor would increase. This would lead to an increase in reaction rate leading to additional energy release. The result could be a runaway reaction with pressures exceeding the bursting pressure of the reactor. The temperature within the reactor is measured and is used to control the cooling water flow rate by a valve. Perform HAZOP Study

28. Prel i mi nary HAZOP on 32 R e a c t o r - C a uses Action Guide Word NO Deviation No cooling Exampl e Consequences Temperature increase in reactor REVERSE Reverse cooling flow Failure of water source resulting in backward flow M O RE More cooling flow Instruct operators on procedures AS WELL AS Reactor product in coils Check maintenance procedures and schedules OTHER THAN Another material besides cooling water Water source co n t a m in a t e d

29. Prel i mi nary HAZOP on Reac t or – Ans wer Deviation Causes Consequences Action 33 Guide Word N O No cooling Cooling water valve malfunction Temperature increase in reactor Install high temperature alarm (TAH) REVERSE Reverse cooling flow Failure of water source resulting in backward flow Less cooling, possible runaway reaction Install check valve M ORE More cooling flow Control valve failure, operator fails to take action on alarm Too much cooling, reactor cool Instruct operators on procedures AS WELL AS Reactor product in coils More pressure in reactor Off-spec product Check maintenance procedures and schedules OTHER THAN Another material besides cooling water Water source c on t a mi n a t ed May be cooling inefffective and effect on the reaction If less cooling, TAH will detect. If detected, isolate water source. Back up water source?

30. HAZOP - Hazard and Operability 34 HAZ O P N o d es Parameters G u i d e w or d s C o n s eq u e n c e Deviation All of these terms! This stupid table! I hate HAZOPS. Why don’t we just learn the engineering? ATTITUDE CHECK

31. I suppose that I should have done that HAZOP Study! 35

32. 5 7 HAZOP - Hazard and Operability Without HAZOP How will you focus all members of a team on the key issues in a systematic manner? You are responsible for the safety team.