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Hazop method

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Hazop Method

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Hazop method

  1. 1. 1 Hazard and Operabi l i t y ( HAZOP) St udy Dr. AA
  2. 2. 2 HAZOP Fundament al
  3. 3. 3 A s cenari o… • You and your family 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.
  4. 4. 4 Poi nt s t o 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? (5 minutes for brainstorming ideas)
  5. 5. 5 What other possible accidents might happen on the road trip? Can we be prepared before the accident occurs?
  6. 6. Can we make i t more sys t emat i c ? 6 Par amet er Gui dewor d Possi bl e Causes Consequences Act i on Saf eguar d Car speed Too f ast Too sl ow Rushi ng Ski dded when emer gency br ake - Sl ow down - Speed up - ABS br ake syst em - Saf et y bel t - Ai r bag Ti r e No t hr ead Less t hr ead Ti r e t oo ol d, of t en speedi ng and emer gency br eak Car ski dded - Check f r equent l y - Have spar e t i r e Wi ndow vi si bi l i t y Low Ver y l ow Rai n Cannot see t he r oad Car l i ght Di m No l i ght - St op car - Go t o near est gar age - Use emer gency si gnal Road Wi t h hol es Rocky Br eaks t he car t i r e - Put a si gnboar d - St r eet l i ght s Tr avel t i me Ni ght Foggy No st r eet l i ght - Tr avel dur i ng dayl i ght
  7. 7. 7 What is HAZOP? • Systematic technique to IDENTIFY potential HAZard and OPerating problems • A formal systematic rigorous examination to the process and engineering facets of a production facility • A qualitative technique based on “ guide-word s” to help provoke thoughts about the way deviations from the intended operating conditions can lead to hazardous situations or operability problems • HAZOP is basically for safety - Hazards are the main concern - Operability problems degrade plant performance (product quality, production rate, profit) • Considerable engineering insight is required - engineers working independently could develop different results
  8. 8. 8 Ori gi n of HAZOP • Ini t i al l y prepared by Dr H G Lawl ey and as soc i at es of ICI at Wi l t on i n 1960’ s . • Subsequent l y C J Bul l ock and A J D Jenni ng f rom ChE Dept . Tees i de Pol yt echni c under supervi s i on of T. A. Kl et z appl i ed t he met hod at hi gher i ns t i t ut i on ( pos t - graduat e l evel ) . • In 1977, Chemi cal Indus t ri es As soc i at i on publ i shed t he edi t ed vers i on.
  9. 9. 9 Lat er Devel opment - HAZOP • ICI expanded t he procedure cal l ed HAZARD STUDY s t eps 1 t o 6. • The ICI s i x s t eps :  Proj ec t expl orat i on / prel imi nary proj ec t asses sment – t o i dent i f y i nherent hazards of proces s chemi cal s , s i t e sui t abi l i t y and probabl e envi ronment al impac t .  Proj ec t def i ni t i on – t o i dent i f y and reduce si gni f i cant hazards assoc i at ed wi t h i t ems and areas, check conf ormi t y wi t h rel evant st andards and codes of prac t i ces . USE CHECK LI STS
  10. 10. Lat er Devel opment - HAZOP  Des i gn and procurement – t o exami ne t he PID 10 i n det ai l f or i dent i f i cat i on of devi at i ons f rom des i gn i nt ent capabl e of causi ng operabi l i t y probl ems or hazards.  Duri ng f i nal s t ages of cons t ruc t i on – t o check t hat al l recommended and ac cept ed act i ons recorded i n s t eps i , i i and i i i impl ement ed.  Duri ng pl ant commi ss i oni ng – t o check t hat al l rel evant s t at ut ory requi rement s have been acknowl edges and al l i ns t al l ed saf et y sys t ems are rel i abl y operabl e.
  11. 11. 11 Lat er Devel opment - HAZOP  Duri ng normal operat i on, some t ime af t er s t art - up – espec i al l y i f any modi f i cat i on been made. To check i f changes i n operat i on has not i nval i dat ed t he HAZOP report of s t ep i i i by i nt roduc i ng new hazards . Thi s procedures are adopt ed f ul l y or part l y by many compani es around t he worl d.
  12. 12. 12 Objective of HAZOP • 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.
  13. 13. • HAZOP identifies potential hazards , failures and operability problems. • Its use is recommended as a principal method by professional institutions and legislators on the basis of proven capabilities for over 40 years. • It is most effective as a team effort consists of plant and prices designers, operating personnel, control and instrumentation engineer etc. • It encourages creativity in design concept evaluation. • Its use results in fewer commissioning and operational problems and better informed personnel, thus confirming overall cost effectiveness improvement. 13 How and Why HAZOP is Used
  14. 14. • Necessary changes to a system for eliminating or reducing the probability of operating deviations are suggested by the analytical procedure. • HAZOP provides a necessary management tool and bonus in so far that it demonstrates to insurers and inspectors evidence of comprehensive thoroughness. • HAZOP reports are an integral part of plant and safety records and are also applicable to design changes and plant modifications, thereby containing accountability for equipment and its associated human interface throughout the operating lifetime. 14 How and Why HAZOP is Used
  15. 15. • HAZOP technique is now used by most major companies handling and processing hazardous material, especially those where engineering practice involves elevated operating parameters : - oil and gas production - flammable and toxic chemicals - pharmaceuticals etc • Progressive legislation in encouraging smaller and specialty manufacturing sites to adopt the method also as standard practice. 15 How and Why HAZOP is Used
  16. 16. • It emphasizes upon the operating integrity of a system, thereby leading methodically to most potential and detectable deviations which could conceivably arise in the course of normal operating routine - including "start-up " and "shut-down" procedures - as well as steady-state operations. • It is important to remember at all times that HAZOP is an identifying technique and not intended as a means of solving problems nor is the method intended to be used solely as an undisciplined means of searching for hazardous scenarios. 16 Purpose of HAZOP
  17. 17. 17 HAZOP - Hazard and operability HAZOP keeps all team members focused on the same topic and enables them to work as a team 1 + 1 = 3 NODE: Concentrate on one location in the process PARAMETER: Consider each process variable individually (F, T, L, P, composition, operator action, corrosion, etc.) GUIDE WORD: Pose a series of standard questions about deviations from normal conditions. We assume that we know a safe “normal” operation.
  18. 18. 18 HAZOP - Hazard and operability NODE: Pipe after pump and splitter PARAMETER*: Flow rate GUIDE WORD*: Less (less than normal value) • DEVIATION: less flow than normal • CAUSE: of deviation, can be more than one • CONSEQUENCE: of the deviation/cause • ACTION: initial idea for correction/ prevention/mitigation A group members focus on the same issue simultaneously
  19. 19. Question : How can one be certain to identify all possible deviations ? Answer : No absolute certainty as the study is subjective and 100 % achievement in this context can have no significance. Any individual or corporate effort will yield results directly proportional to the appropriate background experience of those taking part. However, with the appropriate levels of individual project-related expertise , such a procedure is fully capable of identifying at least 80 % of potential deviations which could rise during normal operation. 19 Relevant Question About HAZOP
  20. 20. Separate consideration is demanded for other operating modes, such as commissioning, emergency shut-down procedures and isolation of equipment for maintenance or modification. Once an installation is endorsed by a properly-conducted HAZOP study, it is these non-steady state circumstances which benefit particularly from the technique throughout the life time of the installation. ' Operability' must also consider the human factors involved as well as the prediction of equipment behavior. 20 Relevant Question About HAZOP
  21. 21. Apart from the uniformity of day-to-day activities , hazards which could cause major production interruptions and loss, possibly leading to costly incidents, need to be identified : • Are there chemicals used in the plant which have not been classified as hazard because they are handled in small quantities, are assumed harmless, or are not considered to have long-term toxic effect upon employees? • What hazardous materials are transported to or from the site ? • What routes are taken ? • What would be the consequences of accidental release? 21 Relevant Question About HAZOP
  22. 22. • What effluents are generated by the operation being carried out or contemplated ? What regulations require to be honored for their disposal? • Are chemicals properly packaged & labeled? • Are the consequences of product misuse made absolutely clear? • Have all potential God-made events and man-made incidents (e. g breaches of security, sabotage, electric power failure ) been considered? • Are the codes and standards applicable to each facility and relating to its design , sitting and construction complied with? For example, in pressure vessel design. 22 Relevant Question About HAZOP
  23. 23. 23 Feat ures of HAZOP St udy Subsys t ems of i nt eres t l i ne and val ve, et c Equi pment , Ves sel s Modes of operat i on Normal operat i on St art - up mode Shut down mode Mai nt enance /cons t ruc t i on / i nspec t i on mode Tri gger event s Human f ai l ure Equi pment /i ns t rument /component f ai l ure Suppl y f ai l ure Emergency envi ronment event Ot her causes of abnor mal oper at i on, i ncl udi ng i nst r ument di st ur bance
  24. 24. Feat ures of HAZOP St udy Ef f ec t s wi t hi n pl ant Changes i n chemi cal condi t i ons Changes i n i nvent ory Change i n chemi cal phys i cal condi t i ons 24 Hazardous condi t i ons Rel ease of mat eri al Changes i n mat eri al hazard charac t eri s t i c s Operat i ng l imi t reached Energy source exposed et c . Correc t i ve ac t i ons Change of proces s des i gn Change of operat i ng l imi t s Change of sys t em rel i abi l i t y Improvement of mat eri al cont ai nment Change cont r ol syst em Add/ r emove mat er i al s
  25. 25. 25 Feat ures of HAZOP St udy How woul d hazardous Duri ng normal operat i on condi t i ons det ec t ed ? Upon human f ai l ure Upon component f ai l ure In ot her c i rcums t ances Cont i ngency ac t i ons Improve i sol at i on Improve prot ec t i on
  26. 26. Document s Needed f or HAZOP 26 St udy • For Prel imi nary HAZOP – Proces s Fl ow Sheet ( PFS or PFD ) – Des cri pt i on of t he Proces s • For Det ai l ed HAZOP – Pi pi ng and Ins t rument at i on Di agram ( P & ID ) – Proces s Cal cul at i ons – Proces s Dat a Sheet s – Ins t rument Dat a Sheet s – Int erl ock Schedul es – Layout Requi rement s – Hazardous Area Cl as s i f i cat i on – Des cri pt i on of t he Proces s
  27. 27. 27 Bef ore Det ai l ed HAZOP • The devel opment of t he det ai l ed P&I Di agram i s t he l as t s t age of t he proces s des i gn. • The devel opment wi l l f ol l ow a normal s t andard procedure and i nc l ude t he f ol l owi ng cons i derat i ons : – Bas i c proces s cont rol sys t em - t hi s i s a c l osed l oop cont rol t o mai nt ai n proces s wi t hi n an ac cept abl e operat i ng regi on. – Al arm sys t em - t hi s i s t o bri ng unusual s i t uat i on t o at t ent i on of a person moni t ori ng t he proces s i n t he pl ant – Saf et y i nt erl ock sys t em - t hi s i s t o s t op operat i on or part of t he proces s duri ng emergenc i es . – Rel i ef sys t em - t hi s i s t o di vert mat eri al
  28. 28. 28 P&ID • A Pi pi ng and Ins t rument at i on Di agram - P&ID, i s a s chemat i c i l l us t rat i on of f unc t i onal rel at i onshi p of pi pi ng, i ns t rument at i on and sys t em equi pment component s . • P&ID represent s t he l as t s t ep i n proces s des i gn. • P&ID shows al l of pi pi ng i nc l udi ng t he phys i cal sequence of branches , reducers , val ves , equi pment , i ns t rument at i on and cont r ol i nt er l ocks. • P&ID i s normal l y devel oped f rom proces s f l ow di agram ( PFD) . • The P&ID are used t o operat e t he proces s sys t em. • A proces s cannot be adequat el y des i gned wi t hout proper P&ID.
  29. 29. P&I D A P&ID shoul d i nc l ude: ( Basi cal l y every mechani cal aspec t of t he pl ant wi t h 29 some except i ons ) • Ins t rument at i on and des i gnat i ons • Mechani cal equi pment wi t h names and numbers • Al l val ves and t hei r i dent i f i cat i ons • Proces s pi pi ng, s i zes and i dent i f i cat i on • Mi s cel l aneous - vent s , drai ns , spec i al f i t t i ngs , sampl i ng l i nes , reducers , i ncreasers and swagers • Permanent s t art - up and f l ush l i nes • Fl ow di rec t i ons • Int erconnec t i ons ref erences • Cont rol i nput s and out put s , i nt erl ocks • Int erf aces f or c l as s changes • Sei smi c cat egory • Qual i t y l evel • Annunc i at i on i nput s • Comput er cont rol sys t em i nput • Vendor and cont rac t or i nt erf aces • Ident i f i cat i on of component s and subsys t ems del i vered by ot hers • Int ended phys i cal sequence of t he equi pment
  30. 30. A P&ID shoul d not i nc l ude: • Ins t rument root val ves • cont rol rel ays • manual swi t ches • equi pment rat i ng or capac i t y • primary i ns t rument t ubi ng and val ves • pres sure t emperat ure and f l ow dat a • el bow, t ees and s imi l ar s t andard f i t t i ngs • ext ens i ve expl anat ory not es 30 P&I D
  31. 31. 31 P&ID and Saf et y • P&I Di agram – ISA St andard – DIN St andard • Layers of prot ec t i on
  32. 32. • Procedure in HAZOP study consist of examining the process and instrumentation (P&I) line diagram , process line by process line . • A list of guide words is used to generate deviations from normal operation corresponding to all conceivable possibilities. • Guide words covering every parameter relevant to the system under review :i.e. flow rate and quality, pressure, temperature, viscosity, components etc. • Flowchart for application of HAZOP is shown in figure. 32 HAZOP St udy Procedure
  33. 33. 33 HAZOP St udy Fl ow Chart Select Line Select deviation e. g more flow Is Move on to next more flow possible deviation Is it hazardous or does it prevent efficient operation ? Will the operator know that there is more flow ? What changes in plant or method will prevent the deviation or make it less likely or protect against the consequences ? Is the cost of the change justified ? Agree change (s) Agree who is responsible for action Consider other causes of more flow What change in plant will tell him ? Consider other change(s) or agreed to accept hazard Follow up to see action has been taken
  34. 34. 34 Gui del i nes f or Di vi s i on i nt o Sec t i ons • Choi ces of l i nes – P&ID mus t be di vi ded l ogi cal l y. Not t oo many sec t i ons . Fac t ors t o be cons i dered : – Each sec t i on shoul d cont ai n ac t i ve component s , whi ch gi ves ri se t o devi at i ons . E. g pi pi ng whi ch cont ai ns cont rol val ves can gi ve ri se t o f l ow devi at i ons , heat exchangers can cause T devi at i ons . – Mat eri al s i n sec t i on – cont ai n s i gni f i cant amount of hazardous mat eri al s . – Sec t i on based on proces s and s t at es of mat eri al s . Onl y 1 proces s operat i on per 1 sec t i on.
  35. 35. 35 Gui del i nes f or Di vi s i on i nt o Sec t i ons • General gui del i nes : – Def i ne each maj or proces s component as a sec t i on. Usual l y anyt hi ng as s i gned equi pment number shoul d be cons i dered a maj or proces s component . – Def i ne one l i ne sec t i on between each maj or proces s component . – Def i ne addi t i onal l i ne sec t i ons f or each branches of f t he mai n proces s f l ow. – Def i ne a proces s sec t i on at each connec t i on t o exi s t i ng equi pment .
  36. 36. 36 Gui del i nes f or Di vi s i on i nt o Sec t i ons • Suppl ement ary gui del i nes – Def i ne onl y one proces s sec t i on f or equi pment i n i dent i cal servi ce. However, pumps i n di f f erent servi ce wi t h a common spare mus t be t reat ed separat el y. – Def i ne onl y one l i ne at t he end of a seri es of component s i f t here are no ot her f l ow pat hs . – Def i ne onl y one addi t i onal l i ne sec t i on i f t here are al t ernat i ve f l ow pat hs , regardl es s of how many branches t here are.
  37. 37. • Do not def i ne l i ne between maj or equi pment i t ems i f t here are no s i ngl e ac t i ve component s t hat coul d cause devi at i ons . • Do not def i ne sec t i ons f or exi s t i ng equi pment t hat i s ups t ream of new or modi f i ed equi pment . Addres s mal f unc t i ons of such ups t ream equi pment as devi at i ons i n t he new or modi f i ed equi pment . 37 Gui del i nes f or Di vi s i on i nt o Sec t i ons
  38. 38. 38 HAZOP Study Procedure GUIDE WORDS * POSSIBLE CAUSES DEVIATION ( FROM DESIGN AND/OR OPERATING INTENT ) CONSEQUENCES ACTION(S) REQUIRED OR RECOMMENDEED
  39. 39. Guide Words NONE No forward flow when there should be MORE More of any parameter than there should be, e.g more flow, more pressure, more temperature, etc. LESS As above, but "less of" in each instance PART System composition difference from what it 39 should be MORE THAN More "components" present than there should be for example, extra phase, impurities OTHER What needs to happen other than normal operation, e.g. start up,shutdown, maintenance
  40. 40. Guide Words NONE e.g., NO FLOW caused by blockage; pump failure; 40 valve closed or jammed : leak: valve open ;suction vessel empty; delivery side over - pressurized : vapor lock ; control failure REVERSE e.g., REVERSE FLOW caused by pump failure : NRV failure or wrongly inserted ; wrong routing; delivery over pressured; back- siphoning ; pump reversed MORE OF e.g., MORE FLOW caused by reduced delivery head ; surging ; suction pressurised ; controller failure ; valve stuck open leak ; incorrect instrument reading.
  41. 41. Guide Words MORE 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. LESS OF e.g., LESS FLOW caused by pump failure; leak; scale in delivery; partial blockage ; sediments ; poor suction head; process turndown. LESS e.g., low temperature, pressure caused by Heat loss; vaporisation ; ambient conditions; rain ; imbalance of input and output ; sealing ; blocked vent . 41 PART OF Change in composition high or low concentration of mixture; additional reactions in reactor or other location ; feed change.
  42. 42. MORE THAN 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. OTHER 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. 42 Guide Words
  43. 43. 43 HAZOP STUDY REPORT FORM TITLE : Sheet 1 of LINE 1 : DEVIATION CAUSES CONSEQUENCES EXISTING PROVISIONS ACTIONS, QUESTIONS OR RECOMMENDATIONS HAZOP Study Form
  44. 44. 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. 44 HAZOP Study
  45. 45. • HAZOP is a systematic, reasonably comprehensive and flexible. • It is suitable mainly for team use whereby it is possible to incorporate the general experience available. • It gives good identification of cause and excellent identification of critical deviations. • The use of keywords is effective and the whole group is able to participate. • HAZOP is an excellent well-proven method for studying large plant in a specific manner. • HAZOP identifies virtually all significant deviations on the plant, all major accidents should be identified but not necessarily their causes. 45 Strength of HAZOP
  46. 46. • HAZOP is very time consuming and can be laborious with a tendency for boredom for analysts. • It tends to be hardware-oriented and process-oriented, although the technique should be amenable to human error application. • It tends to generate many failure events with insignificance consequences and generate many failure events which have the same consequences. • It stifles brainstorming although this is not required at the late stage of design when it is normally applied. • HAZOP does not identify all causes of deviations and therefore omits many scenarios. 46 Weakness of HAZOP
  47. 47. • It takes little account of the probabilities of events or consequences, although quantitative assessment are sometime added. The group generally let their collective experiences decide whether deviations are meaningful. • HAZOP is poor where multiple-combination events can have severe effects. • It tends to assume defects or deterioration of materials of construction will not arise. • When identifying consequences, HAZOP tends to encourage listing these as resulting in action by emergency control measures without considering that such action might fail. It tends to ignore the contribution which can be made by operator interventions 47 Weakness of HAZOP
  48. 48. 48 Managi ng HAZOP How to manage HAZOP
  49. 49. 49 Prel imi nary HAZOP Exampl e TC Cooling Coils Monomer 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
  50. 50. 50 Prel imi nary HAZOP on Reac t or - Exampl e Guide Word Deviation Causes Consequences Action NO No cooling Temperature increase in reactor REVERSE Reverse cooling flow Failure of water source resulting in backward flow MORE 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 contaminated
  51. 51. 51 Prel imi nary HAZOP on Reac t or – Answer Guide Word Deviation Causes Consequences Action NO 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 MORE 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 contaminated May be cooling inefffective and effect on the reaction If less cooling, TAH will detect. If detected, isolate water source. Back up water source?
  52. 52. Case St udy – Shel l & Tube Heat 52 Exchanger • Us i ng rel evant gui de works , perf orm HAZOP s t udy on shel l & t ube heat exchanger Process fluid Cooling water
  53. 53. 53 HAZOP on Heat Exchanger – Answer 1 Guide Word Deviation Causes Consequences Action Less Less flow of cooling water Pipe blockage Temperature of process fluid remains constant High Temperature Alarm More More cooling flow Failure of cooling water valve Temperature of process fluid decrease Low Temperature Alarm More of More pressure on tube side Failure of process fluid valve Bursting of tube Install high pressure alarm Contamination Contamination of process fluid line Leakage of tube and cooling water goes in Contamination of process fluid Proper maintainance and operator alert Corrosion Corrosion of tube Hardness of cooling water Less cooling and crack of tube Proper maintainence
  54. 54. 54 HAZOP on Heat Exchanger – Answer 2 Guide Word Deviation Causes Consequences Action NONE No cooling water flow Failure of inlet cooling water valve to open Process fluid temperature is not lowered accordingly Install Temperature indicator before and after the process fluid line Install TAH MORE More cooling water flow Failure of inlet cooling water valve to close Output of Process fluid temperature too low Install Temperature indicator before and after process fluid line Install TAL LESS Less cooling water Pipe leakage Process fluid temperature too low Installation of flow meter REVERSE Reverse process fluid flow Failure of process fluid inlet valve Product off set Install check valve (whether it is crucial have to check?) CONTAMINATION Process fluid contamination Contamination in cooling water Outlet temperature too low Proper maintenance and operator alert
  55. 55. Consequence 55 HAZOP - Hazard and Operability ATTITUDE CHECK HAZOP Nodes Parameters Guide words Deviation All of these terms! This stupid table! I hate HAZOPS. Why don’t we just learn the engineering?
  56. 56. 56 I suppose that I should have done that HAZOP Study!
  57. 57. 57 HAZOP - Hazard and Operability You are responsible for the safety team. Without HAZOP How will you focus all members of a team on the key issues in a systematic manner?
  58. 58. 58 Case St udy Case study hydrogen plant
  59. 59. 59 Sampl e Answers result HAZOP reactor.doc
  60. 60. 60 HAZOP Management
  61. 61. 61 Planning for HAZOP Study What is required? • Define objectives and scope – define TOR and scope of work. •To new design – applied to a detailed design. •To existing design – identify hazards not previously identified probably because not being HAZOPED. •To plant modification • Select team members. Two types of person needed : •Detailed technical knowledge of the process. •Those with knowledge and experience of applying highly structured, systematic HAZOP approach.
  62. 62. 62 Pl anni ng f or HAZOP • Prepare f or t he s t udy. Need suf f i c i ent i nf ormat i on : • Pr ocess Fl ow Sheet ( PFS or PFD ) • Pi pi ng and I nst r ument at i on Di agr am ( P & I D ) • Pr ocess Cal cul at i ons • Pr ocess Dat a Sheet s • I nst r ument Dat a Sheet s • I nt er l ock Schedul es • Layout Requi r ement s • Hazar dous Ar ea Cl assi f i cat i on • Oper at i ng i nst r uct i ons
  63. 63. 63 Pl anni ng f or HAZOP • Prepare f or t he s t udy. Need suf f i c i ent i nf ormat i on : • Saf et y pr ocedur es document s • Rel i ef / vent i ng phi l osophy • Chemi cal i nvol ved • Pi pi ng speci f i cat i ons • Pr evi ous HAZOP r epor t
  64. 64. 64 Pl anni ng f or HAZOP • Carry out t he s t udy • Record t he resul t s ( may need a secret ary) • Fol l ow- up of ac t i ons not ed – f i nal report cont ai n resol ut i on of al l recommended ac t i ons – mus t appoi nt someone as l eader t o check progres s of ac t i on – t eam may meet agai n i f answers t o ques t i ons do not s impl y l ead t o an ac t i on – t eam may meet agai n i f s i gni f i cant des i gn changes i n i nt erim report
  65. 65. 65 Team Charac t eri s t i c s – Members share common obj ec t i ves . – Everybody cont ri but es and knows hi s/her rol es , not l eader dependent t oo much. – Each members val ues and respec t s cont ri but i on of ot hers . – Members l earn whi l e t hey work. – Over a peri od of t ime, i ndi vi dual cont ri but i on l evel are more or l es s equal . – Di sagreement are worked t hrough by di s cus s i on. – The use of vot i ng procedures i s spari ng and normal l y onl y l as t resort i f hi ghl y neces sary. – Members enj oy t eam meet i ngs .
  66. 66. 66 Ques t i oni ng Techni ques • Open ques t i ons – Hel p person bei ng asked t o t hi nk – use words how, what and why. • Cl osed ques t i ons – To f ocus on an i s sue or probl em. St art wi t h words who, when, where. – Requi red answer yes or no onl y. • Ques t i on mi x – Mi x between open and c l osed ques t i ons .
  67. 67. 67 Ques t i oni ng Techni ques • Thi ngs t o avoi d – Ambi guous or vague ques t i ons . – Doubl e barel l ed/mul t i pl e ques t i ons . – Long compl i cat ed ques t i ons . – Int errogat i on t ype of ques t i ons . – A l oaded ques t i ons – impl i ed j udgement .
  68. 68. Respons i bi l i t y of HAZOP Team 68 HAZOP leader Members • Plan sessions and timetable • Control discussion • Limit discussion • Encourage team to draw conclusion • Ensure secretary has time for taking note • Keep team in focus • Encourage imagination of team members • Motivate members • Discourage recriminations • Judge importance issues
  69. 69. 69 Checkl i s t f or HAZOP Leader • Al ways prepare s t udy program i n advance. • Agree on t he f ormat or f orm t o be used. • Prepare f ol l ow up procedures . • Bri ef members about HAZOP duri ng f i rs t meet i ng. • St op t he t eam t ryi ng t o redes i gn t he proces s . • HAZOP i s a t eam exerc i se. Do not l et anybody ( i nc l udi ng t he l eader himsel f t o domi nat e) .
  70. 70. Checkl i s t f or HAZOP Leader • If conf l i c t ari ses , handl e wi t h care. • Avoi d l ong di s cus s i ons by recordi ng areas whi ch need t o be resol ved out s i de meet i ng. • Leader mus t be s t rong, yet di pl omat i c . • Speak c l earl y. Make you poi nt . • Bet t er have experi ence worki ng as t eam member previ ous l y. • Do not ski p anyt hi ng…. some t ime 70 smal l t hi ngs may cause bi g
  71. 71. Respons i bi l i t y of HAZOP Team 71 HAZOP Secretary Members • Take adequate notes • Record documentations • Inform leader if more time required in taking notes • If unclear, check wording before writing • Produce interim lists of recommendations • Produce draft report of study • Check progress of chase action • Produce final report
  72. 72. Respons i bi l i t y of HAZOP Team 72 Process Engineer Members • Provide a simple description • Provide design intention for each process unit • Provide information on process conditions and design conditions • Provide a simple description • Provide design intention for each process unit • Provide information on process conditions and design conditions
  73. 73. Respons i bi l i t y of HAZOP Team 73 Members Mechanical Design Engineer • Provide specification details • Provide vendor package details • Provide equipment and piping layout information Instrument Engineer • Provide details of control philosophy • Provide interlock and alarm details • Provide info on shutdown, safety features
  74. 74. Respons i bi l i t y of HAZOP Team Plant Engineer or Manager • Provide information on compatibility with any existing adjacent plant • Provide details of site utilities and services • Provide (for study on existing plant) any update on maintenance access and modifications Shift Operating Engineer or Supervisor • Provide guidance on control instrumentation integrity from an operating experience view point • Provide (for study on existing plant) information on plant stability at the specified control parameters • Provide information on experienced operability deviations of hazard potential 74 Members
  75. 75. Respons i bi l i t y of HAZOP Team 75 Chemist Members • Provide details of process chemistry • Provide details of process hazards (polymerisations, byproducts, corrosion etc) Project Engineer • Provide details of cost and time estimation and also budget constraints. • Ensure rapid approval if required

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