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SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR Title slide PIPELINE QRA SEMINAR 1.

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Presentation on theme: "SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR Title slide PIPELINE QRA SEMINAR 1."— Presentation transcript:

1 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR Title slide PIPELINE QRA SEMINAR 1

2 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES 2 Ignition sources Chemical reactions Oil soaked lagging on hot piping Pyrophoric iron sulphide (H 2 S & metal corrosion) Electrical sparks and arcs Electrical motors and generators Switches, relays and other arching components of electrical circuits Electrical wiring mal functioning Electrical welding Lighting fixtures Impressed cathodic protection system Mechanical sparks Lightning

3 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES 3 Static electrical sparks Fuelling operations Filling containers, tanks and pressure vessels High fluid exit velocities (high pressure water sprays, gas jets) Drive belt operation Shot blasting Friction Flame Flaring Fired equipment Gas welding and cutting Hot surfaces Fired vessels stacks Engine exhaust Heat of compression

4 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 4

5 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 5 Definitions:

6 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES Content slide, two columns with image Ignition Probabilities (Liquids): 6

7 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES Content slide, two columns with image Ignition Probabilities (Gas Pipelines): 7

8 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES Content slide, two columns with image 8

9 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES Content slide, two columns with image Aim of Zoning Classification (IP 15): Avoid ignition of those releases that may occur from time to time Reduce to an acceptable minimum level the probability of coincidence of flammable atmosphere and an electrical or other source of ignition Risk Target is 10 -5 year IP 15 does not concern major releases (spread of flammables more than 30 m). These shall be minimised by design and operation to an acceptable residual risk. Hazardous area classification requires an interdisciplinary approach: Process Safety and loss prevention Electrical Agreements reached on hazardous area classification should be formally recorded in a Hazardous Area Dossier in supplement to hazardous areas drawings. For the majority of releases the shape profile depends primarily on angle and location of the release. 9

10 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES 10 Zone 0: The part of a hazardous area in which a flammable atmosphere is continuously present or present for long periods Zone 1: That part of a hazardous area in which a flammable atmosphere is likely to occur in normal operation Zone 2: That part of a hazardous area in which a flammable atmosphere is not likely to occur in normal operation and, if it occurs, will only exist for a short period. Non-Hazardous: areas that do not fall into any of the above. Zoning:

11 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES 11 Continuous grade release: A release that is continuous or nearly so, or that occurs frequently and for short periods Primary grade release: a release that is likely to occur periodically or occasionally in normal operations, i.e. a release which, in operating procedures is anticipated to occur Secondary grade release: A release that is unlikely to occur in normal operation and, in any event, will do so only infrequently and for short periods i.e. a release which in operating procedures is not anticipated to occur. Such release may be of unknown size e.g. fracture of a drain or unknown size e.g. corrosion hole. If it is likely to be present for more than 1000 hours per year. If it is likely to be present for between 10 to 1000 hours per year. If it is likely to be present for 1 to 10 hours per year.

12 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES Content slide, two columns with image Grade of Release: Continuous grade release  Typically Zone 0 Primary grade release  Typically Zone 1 Secondary grade release  Typically Zone 2 “Typically” refers that it is ventilation dependent Grade of release depends solely on frequency and duration. Grade does NOT depend on rate or quantity, ventilation or characteristics of the fluid. 12

13 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES Content slide, two columns with image Fluid Categories: 13

14 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – FLUID CATEGORY Natural gas Unstabilized Crude Stabilized Crude 14

15 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – APPROACH 15 3 Different approaches to zoning: Based on experience and provides hazard radii for typical installations. Open field: Ambient temperature of max. 30°C Wind speed 0.5 m/s – 2 m/s Identify sources Determine grade Establish zone Determine hazard radii Leak size Pressure Draw zone Risk target of 10 -5 per year Unknown leak size Varying release size Consequences Exposure Approach is similar to risk analysis Direct Examples Approach Point Sources Approach Risk Based Approach

16 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – RELEASE RATES Continuous and primary grade release rates are normally well defined as they have been designed for. Secondary grade release rates/ leak holes are often unknown as they occur unintentionally e.g. breakage of a flange, corrosion hole, fracture of a drain etc. Secondary Grades of Release operates with LEVELS: LEVEL I10 -2 / release source year LEVEL II 10 -2 - 10 -3 / release source year LEVEL III 10 -3 - 10 -4 / release source year The LEVEL to be used on a specific plant is based on the exposure of the most exposed individual to flammable releases and the probability of ignition of those releases. LEVEL frequencies are for the zone 2 boundary. 16

17 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE: LEVEL 17 Exposure: Exp = P occ X N range P occ : Probability the worker is on site within the hazardous area. N range : The time weighted average number of release sources which can affect the individual during their time within the hazardous area. Exposure is normally only calculated for the most exposed person and used for the entire installation.

18 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE: LEVEL 18

19 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE: LEVEL 19

20 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE 20 Piping: Fully welded Designed according to ANSI/ASME B31.3 Does not require zoning. Flanges:  Secondary grade release source  Broken flanges Valves:  Infrequently used  Well maintained  Frequently used (Control valves)  Secondary grade  Additional Primary grade of 0.3 m  Primary grade

21 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE 21 Flanges: Ten or more flanges are required within close proximity to create sufficient likelihood of release to justify classification as a secondary release. Fuel gas flange connection to turbine does not require classification.

22 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR HAZARDOUS AREA CLASSIFICATION – POINT SOURCE Flanges & Valves Secondary Grade LEVEL I: 10 -2 / year LEVEL II: 10 -2 – 10 -3 / year LEVEL III: 10 -3 – 10 -4 / year Flange d ≤ 3” : 3.95∙10 -5 per year – 30 off = 0.001185 Flange 3”<d≤11”: 5.56∙10 -5 per year – 10 off = 0.0112 Natural Gas IR; Occupation and ignition P occ = 0.05 (Estimate) N range = 5 (Table) Exposure = 0.25 (P occ x N range) P ig = 0.03 (Table) P ig,total = 0.00037 (0.001185+0.0112) X 0.03 From curve it is seen that we are at LEVEL 1 Calculation Example 22

23 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE 23 Pig Receivers Pig receivers are likely to opened frequently and should normally be regarded as primary grade release. The hazardous area should be classified as zone 1. Provided that interlock systems are in place, the release that occurs from opening the launcher/receiver will be minor and a hazard radius of 3 m is suggested in IP 15. If the operating procedures include purging or water washing before opening the launcher/receiver the nominal hazard radii can be reduced to 1.5 m.

24 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE 24

25 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR HAZARDOUS AREA CLASSIFICATION – POINT SOURCE 25

26 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR HAZARDOUS AREA CLASSIFICATION – POINT SOURCE 26 At ground level

27 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE -VENTILATION 27 Natural ventilation and wind without stagnant zones. Typically air velocities will not be less than 0.5 m/s and will frequently be above 2 m/s. Where a facility is classified as an open area, the hazardous area classification of previous slides applies without further ventilation considerations.

28 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE VENTILATION – ENCLOSED AREAS 28 Area where natural ventilation does not provide a minimum of 12 air changes per hour. 12 acph is defined as adequate ventilation (10 minutes persistence 2. grade release). Displacement ventilation. Dilution ventilation. Localised Exhaust Ventilation (LEV). Forced draught fan (acoustic enclosures). Over- and under-pressurisation

29 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES AREA CLASSIFICATION – POINT SOURCE VENTILATION – ENCLOSED AREAS 29

30 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT 30 As a general policy, electrical equipment should not be located in a hazardous area if it is possible to place it in a non-hazardous area, nor should it be placed in a Zone 1 if it can be placed in Zone 2. Correct selection of equipment requires three factors to be taken into account: Zone in which the equipment will be used. Sensitivity to ignition of the gases or vapour likely to be present, expressed as gas group. Sensitivity of the gases or vapour present to ignition by hot surfaces, expressed as a temperature classification.

31 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 31 TypeProtectionFunctionality/concept oOil filled apparatus. The equipment is submerged in oil preventing an flammable atmosphere to occur in the area where sparks are likely to occur. pPressurisedThe equipment is pressurised with a protective gas to prevent ingress of flammable gasses or liquids. The overpressure can be made with or with out constant flushing of the protective gas. qPowder filledBy filling the housing with a finely grained powder, an arc within the housing is unable, with correct use, to ignite the potentially explosive atmosphere outside. dFlame proofThe enclosure is designed to withstand an explosion and prevent its propagation. The enclosure shall be able to withstand an internal pressure of 12 bar. eIncreased safetyEnclosure in which there is no spark or hot surface in normal operation. iaIntrinsically safe “ia”Limit the energy within the system so that even under fault conditions a spark or thermal effects cannot occur. ibIntrinsically safe “ib”Limit the energy within the system so that a spark or thermal effects cannot occur considering 1 fault. nNon incendiveType n protection has several implementation types: nA: non sparking nC: hermetically sealed enclosure nL: energy limited MEncapsulatedParts that could ignite a potentially explosive atmosphere by means of sparks or heat are potted soas to prevent ignition of the potentially atmosphere. This is achieved by encapsulating the components in a compound resistant to physical - especially electrical, thermal and mechanical - and chemical influences. FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT

32 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 32 FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT

33 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 33 For ”o”, ”d”, ”i” and ”n” there is a material subgroup division: IIA IIB IIC FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT

34 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 34 Intrinsic safe, ia ’ia’ Intrinsic, ib ’ib’ Non incendive ’n’ Encapsulating ’m’ FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT - SUMMARY

35 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 35 FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT –TYPICAL PRACTICE

36 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 36 Instrumentation for use in hazardous areas shall be suitable for at least Zone 1 Instrumentation for use in unclassified areas, which is required to remain energised during an emergency, shall also be suitable for Zone 1. Instrument ”electrical systems” shall by preference be intrinsically safe (IS). Equipment shall comply with at least temperature Class T3, Group IIB. FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT –TYPICAL PRACTICE Instrument ”electrical systems” shall by Equipment comply with at least temperature Class T3, Group IIB. All electrical apparatus located outdoor, shall be certified according to EU directive 94/9/EC (ATEX) and shall as minimum be certified for Equipment Group II Category 2G, Explosion group IIB, temperature class T3.

37 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 37 To aid maintenance and demonstrate that ignition hazards have been properly addressed, an inventory of equipment installed in a hazardous area should be maintained, including: Type of protection Temperature class Subgroup of apparatus Location Marking FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT –DOCUMENTATION

38 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR 38 Battery rooms should be adequately ventilated in order to assist in the dispersion of hydrogen. Electrical apparatus thus may need to be suitable for use in zone 1 hazardous areas with apparatus of subgroup IIC T1 class suitability for hydrogen unless there is dilution by LEV. FREQUENCY ASSESSMENTS & IGNITION PROBABILITIES EX EQUIPMENT Battery Rooms IP 15 is designed for selection and location of fixed electrical equipment. However hazardous area classification is a good basis for deciding what equipment may be used at any particular location. This is in accordance with the ATEX Directives, which apply equally to electrical and non-electrical capable of causing an ignition of a flammable atmosphere. Non-electrical Equipment

39 SEPTEMBER 8-12, 2014 INOGATE PIPELINE QRA SEMINAR END OF FREQUENCY ASSESSMENTS & IGNISTION PROBABILITIES End slide 39


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