GP 76-01 13 December 2005 - Guidance on Practice for HSSE in Design and Loss Prevention

Guidance on Practice for HSSE in Design and Loss Prevention

GP 76-01

BP GROUP ENGINEERING TECHNICAL PRACTICES

Document No. GP 76-01

Applicability Group

Date 13 December 2005

13 December 2005 GP 76-01 Guidance on Practice for HSSE in Design and Loss Prevention

Downloaded Date: 6/17/2008 11:41:44 PM The latest update of this document is located in the BP ETP and Projects Library

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Foreword

This is the first issue of Engineering Technical Practice (ETP) BP GP 76-01.

Copyright 2005, BP Group. All rights reserved. The information contained in this document is subject to the terms and conditions of the agreement or contract under which the document was supplied to the recipient’s organization. None of the information contained in this document shall be disclosed outside the recipient’s own organization without the prior written permission of Director of Engineering, BP Group, unless the terms of such agreement or contract expressly allow.



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Table of Contents

Page

1. Scope .................................................................................................................................... 4

2. Normative references............................................................................................................. 4

3. Terms and definitions............................................................................................................. 4

4. Symbols and abbreviations .................................................................................................... 4

5. General.................................................................................................................................. 4

6. HSSE in design...................................................................................................................... 4 6.1. Purpose ...................................................................................................................... 4 6.2. Risk management in plants and facilities .................................................................... 4 6.3. Simplicity of design and waste minimisation................................................................ 4 6.4. Inherently safer design (ISD) ...................................................................................... 4 6.5. PHSSER - HSSE reviews during projects ................................................................... 4 6.6. Safer designs using constructability VIP ..................................................................... 4 6.7. Safer designs by addressing maintainability and operability........................................ 4 6.8. Security in designs...................................................................................................... 4 6.9. Designing for environmental issues ............................................................................ 4 6.10. Designing for Compliance ........................................................................................... 4

7. Loss prevention and risk control............................................................................................. 4 7.1. Purpose ...................................................................................................................... 4 7.2. ETPs for design .......................................................................................................... 4 7.3. Mitigation of fire related hazards ................................................................................. 4 7.4. Hazard detection and alarm signalling ........................................................................ 4 7.5. Toxic hazards and oxygen deficient atmospheres....................................................... 4 7.6. Hydrocarbon and toxic spill mitigations ....................................................................... 4

Bibliography .................................................................................................................................... 4

List of Tables

Table 1 - Environmental design steps ............................................................................................. 4

Table 2 - Environmental decision making process .......................................................................... 4

List of Figures

Figure 1 - Capital value process (CVP) ........................................................................................... 4

Figure 2 - Waste minimisation and management VIP during CVP................................................... 4

Figure 3 - ISD hazard management flowchart ................................................................................. 4



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1. Scope

a. This Guidance on Practices (GP) provides guidance on health, safety, security, and environment (HSSE) and compliance in design.

b. This GP is applicable to all business units and locations.

c. This GP includes information relevant to business managers, project managers, project engineers, and design engineers.

This GP will provide the business manager, project manager, project engineer, and project design engineer information on what to include and where to go for further guidance when designing a BP plant or facility to meet the of the Integrity Management Functional Standard (IMFS), the Global or USA HSSE Compliance Framework, and HSSE in projects.

This GP will focus on which ETP documents contribute to HSSE in Design or to an Inherently Safer Design. Links to useful HSSE information are included in the GP.

d. The overall goal of “HSSE in Design” is to protect human life (BP employees, BP contractors, and the general public) and the environment against possible accidents (fires, explosions, liquid spills to ground or to water, or emissions to the air) caused by failures of BP plants or facilities in all locations around the world.

e. The main aim of “HSSE in Design” is to ensure that measures are used to minimize the risk and to mitigate the consequences of accidental hazardous material releases, fires, or explosions. These incidents could occur in BP plants and facilities and BP personnel need to address the identified risks to minimize or eliminate them, to achieve the goal stated above and to protect our company reputation and BP company property.

f. This document defines what Group ETPs used to building plants and facilities will contribute to the above goal of HSSE in Design and provide inherently safe designs.

2. Normative references

The following normative documents contain requirements that, through reference in this text, constitute requirements of this technical practice. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this technical practice are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.

BP GIS 14-011 Noise Control - Procurement. GIS 22-201 Procurement of Flares to API 537. GIS 30-801 SIS - Design and Engineering of Logic Solvers. GIS 30-851 Fire and Gas Detection. GP 04-10 Drainage Systems and Sewers. GP 04-20 Civil Engineering GP 04-30 Design of Buildings Subject to Blast Loading. GP 12-60 Hazardous Area Electrical Installations GP 14-01 Noise Control. GP 22-20 Design of Flares to API 537. GP 24-03 Concept Selection for Inherently Safer Design.



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GP 24-20 Offshore Fire & Explosion Hazard Management. GP 24-10 Fire Protection - Onshore. GP 30-25 Field Instruments - General. GP 30-75 SIS - Management of the SIS Lifecycle. GP 30-76 SIS - Process Requirements Specification. GP 30-80 SIS - Implementation of Process Requirements. GP 30-81 SIS - Operations and Maintenance. GP 30-85 Fire and Gas Detection. GP 35-10 Engineering Design for Maintainability. GP 44-10 Plant Layout. GP 44-25 Depressurisation. GP 44-60 Area Classification IP-15 GP 44-65 Area Classification API-500 GP 44-70 Over Pressure Protection Systems. GP 44-80 Design of Relief Disposal Systems. GP 46-01 New Pressure Vessels. GP 48-01 Project HSSE Review (PHSSER). GP 48-50 Major Accident Risk Process. GP 62-01 Valve Selection. IMFS Integrity Management Functional Standard (BP Group Technology). VIPs Constructability VIP (Excellence in Project Management). Process Simplification VIP (Excellence in Project Management). Waste Minimization and Management VIP (Excellence in Project

Management) HSSE for Projects. Getting HSSE Right for Projects (or “in” Projects). Value improving practice (VIP) documents: Process simplification. Waste minimisation and management. Design to capacity. Facilities system performance. Technology selection. Value engineering. Setting business priorities. Constructability.

American Petroleum Institute (API) STD 2218 Fireproofing Practices in Petroleum and Petrochemical Processing Plants.

3. Terms and definitions

For the purposes of this GP, the following terms and definitions apply:

Active fire protection

a. Equipment, systems, and methods required for detection, alarming, control, and extinguishing of fires using water, steam, dry powder, or gaseous extinguishants.



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b. Example would be detection equipment that activates fixed extinguishing or control systems for fire, smoke, gas, or heat.

Fire exposed envelope

a. Space into which fire potential equipment can release combustible fluids that can cause substantial fire damage.

b. Unless specified otherwise, fire exposed envelope shall extend from source of liquid fuel horizontally 6 m to 9 m (20 ft to 30 ft) and vertically 9 m to 12 m (30 ft to 40 ft).

Fire scenario envelopes Fire scenario envelopes are three dimensional spaces into which fire potential equipment can release flammable or combustible fluids that, if ignited, will burn for sufficient time and intensity to inflict escalation.

Fire potential Applicable to plant and equipment (but excluding pipe work) that contain combustible fluids (see API 2218).

Passive fire protection (PFP)

a. Non combustible materials that, for defined period during fire, protect equipment, prevent collapse of structural supports, or limit spread of fire.

b. Passive fire protection incorporates basic requirements for area separation and classification.

4. Symbols and abbreviations

For the purpose of this GP, the following symbols and abbreviations apply:

BLEVE Boiling liquid expanding vapour explosion.

Capex Capital expenditures.

CPSSR Capital project security support review.

CVP BP’s proprietary Capital Value Process comprised of 5 stages: Appraise, Select, Define, Execute, and Operate. More Information on CVP

DSP Decision Support Package

ESD Emergency shutdown.

ETPs Engineering Technical Practices. More Information on ETPs

FEHMP Fire and explosion hazard management plan.

FEL Front end loading.

HAZID Hazard identification.

HAZOP Hazard and operability review.

HSSE Health, safety, security, and environment.



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IMFS Integrity management functional standard.

ISD Inherently safer design.

JV Joint venture (BP and partner company owning and/or operating plant or facility).

LFL Lower flammability limit.

LNG Liquefied natural gas.

LPG Liquefied petroleum gas.

MAP Major accident potential.

MAR Major accident risk (process).

MOC Management of change (process or system).

NGO Non governmental organisation.

Opex Operational expenditures.

P&ID Piping and instrument diagram.

PEL Permissible exposure limit.

PFD Process flow diagram.

PFP Passive fire protection.

PHA Process hazard analysis.

PHSSER Project health safety security and environmental review.

QRM Qualitative risk matrix.

SIS Safety instrumented systems.

STP Site technical practice.

TLV Threshold limit value.

TWA Time weighted average.

VIP Value improving practice.

5. General

a. All business segments at all locations shall systematically identify hazards arising from normal and abnormal operations and shall eliminate, control, or mitigate hazards such that residual risks and all legal HSSE compliance requirements are managed.

This is a requirement of the IMFS.

b. Each location shall have formal procedures that shall ensure hazards are identified, risk assessments are made, and systems developed to manage risks and meet all legal HSSE compliance requirements.



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c. These activities shall be appropriate to and consistent with complexity of location and risks present.

d. For all projects and turnarounds, formal review of health, safety, security, and environmental impacts shall be performed at key stages of project or activity. Each location shall comply with Control of Work Standard.

e. All BP locations shall apply “inherently safer design” principles during design process and use approved Site Technical Practices (STPs). Project teams shall address full life cycle risks.

This is a requirement of the IMFS.

f. Assessment of Major Accident Potential (MAP) using Group Major Accident Risk Process shall be performed for each location. (Each Segment shall confirm that it does not and will not operate above the Group Priority Line and is focused on continuous risk reduction.)

g. STPs

1. All locations shall use a set of STPs that are consistent with BP Engineering Technical Practices (ETPs).

2. Differences shall be justified and approved by appropriate engineering authority based on any specific local requirement.

3. Once in operation, operating, maintenance, and inspection practices shall be implemented and regularly reviewed against approved STPs.

4. All engineered systems, including mechanical, electrical, control, lifting, and structural, shall be designed, procured, constructed operated, inspected, tested, and maintained in accordance with STP to ensure that equipment is fit for service, avoids loss of containment, and maintains structural integrity for expected lifecycle of facility.

5. New plant designs shall minimise risk at source and consider best available technology to improve integrity.

h. Responsibility to ensure compliance with legislation and any other statutory requirements lies with the user.

i. A legal HSSE applicability register shall be maintained that identifies all applicable HSSE regulatory, contractual and other requirements that pertain to the location. Risk prioritization shall be performed as part of the HSSE management system to determine those compliance activities which carry the most risk and therefore require attention to mitigate and/or manage in priority order.

j. This GP should be adapted or supplemented to ensure compliance for specific applications.

6. HSSE in design

6.1. Purpose

HSSE in design is most important aspect of risk management.

Risk is defined as measure of:

• Human injury. • Environmental damage. • Economic loss.

Risk is defined in terms of:

• Incident likelihood.



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• Magnitude of loss, injury, or damage.

Effort to reduce risk arising from operation of plants and facilities can be directed towards:

• Reducing likelihood of incidents (incident frequency). • Reducing magnitude of loss, injury, or damage should an incident occur

(incident consequences).

6.2. Risk management in plants and facilities

6.2.1. Risk identification

a. Business segments shall:

1. Systematically identify hazards arising from normal and abnormal operations.

2. Eliminate, control, or mitigate hazards such that residual risks are managed

3. Manage legal HSSE compliance requirements in the country in which they operate.

b. Each location shall have formal procedures and processes in place to ensure:

1. Hazards are identified.

2. Risk assessments are made.

3. Systems are developed to manage risks.

4. Legal HSSE compliance requirements are met.

c. Procedures shall be appropriate to and consistent with complexity of location and risks present.

d. Assessment of major accident potential using the MAR process shall be performed for each project and location and shall comply with GP 48-50.

e. Each segment shall confirm that it:

1. Does not and will not operate above the group priority line.

2. Is focused on continuous risk reduction.

Greatest benefit of major accident risk (MAR) process will be gained if implemented at beginning of capital value process (CVP) define, execute, and operate stages.

f. Hazard identification and risk assessments shall:

1. Cover design, procurement, construction, and commissioning.

2. Employ process hazard analyses.

3. Be performed by teams that are competent and have comprehensive experience and knowledge of process being evaluated and technique in use.

g. Findings shall be communicated to workforce that may be affected by recommendations and actions.

h. Project teams shall address full lifecycle risks.

i. Hazard Register shall be prepared for each.

j. Hazard Register shall describe hazards and provide clear links from identified hazards to measures, systems, processes, and procedures implemented to manage risks.

k. A legal HSSE applicability register shall be maintained that identifies all applicable HSSE regulatory, contractual and other requirements that pertain to the location. Risk prioritization shall be performed as part of the HSSE management system to determine



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those compliance activities which carry the most risk and therefore require attention to mitigate and/or manage in priority order.

l. Risk assessments and process hazard analyses shall include identification of specific hazards.

m. Accepted recommendations from studies shall be implemented in a timely manner to eliminate hazard or minimise risk from hazard.

6.2.2. Risk reduction

6.2.2.1. General

Strategy for reducing risk, whether directed towards reducing frequency or mitigating consequence of potential accidents, can be classified into four categories, in decreasing order of reliability and preference:

a. Inherent.

b. Passive.

c. Active.

d. Procedural.

6.2.2.2. Inherent

Inherent strategies eliminate hazard by use of materials or process conditions that are less hazardous (e.g., substituting water for flammable solvent).

6.2.2.3. Passive

a. Passive strategies minimising hazard by process and equipment design features that reduce either frequency or consequence of hazard without employing active functioning safety devices.

b. Examples of passive methods include equipment rated for higher pressure, proper selection of materials, safety distance, adherence to good design practices and industry standards, and consideration of human factors.

c. For fires, passive fire protection (PFP) is normally used if equipment or structures are located in fire exposed envelope or fire scenario envelope.

6.2.2.4. Active

a. Active means using equipment, such as controls, safety interlocks, and emergency shutdown (ESD) systems, to detect and correct process deviations.

b. Active systems are commonly referred to as engineering controls.

Examples of active systems include overpressure protection and vent systems, depressurisation systems, proper selection of redundancies in critical and other selected control functions, process isolation and shutdown systems, and corrosion control and monitoring program.

c. Active fire protection systems shall be used on fire potential process equipment for potential of fire from leak or explosion.

6.2.2.5. Procedural

a. Procedural strategies use operation procedures, training, administrative checks, emergency response, and other management approaches to prevent incidents or to minimise effects of incidents.

Example of procedural method is hot work procedures and permit.



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b. Procedural methods are commonly referred to as administrative controls.

6.3. Simplicity of design and waste minimisation

6.3.1. General

Simplicity is valued tool to meet HSSE goals.

Simplicity is designing plant facilities to eliminate unnecessary complexity without unduly restricting operating flexibility, reducing opportunities for error and mis-operation. Also the potential for subsequent HSSE non-compliance issues will be reduced.

Simpler plants are generally safer and more cost effective than complex ones.

a. Business and engineering project team and process design engineer should use value improving practice (VIP) tools to help simplify processing design of plant or facility.

b. Information on VIP tools can be found in group technology portal http://technology.bpweb.bp.com/, under capital productivity, then excellence in project management. Link to VIP page is http://projects.bpweb.bp.com/vip/index.htm.

c. VIPs used to achieve simplicity of design are briefly discussed in �6.3.2 through �6.3.4.

6.3.2. Process simplification VIP

a. Process simplification VIP is disciplined analytical method for reducing:

1. Process complexity and process hazards.

2. Investment requirements.

3. Operating costs.

b. Process simplification works by combining, eliminating, and/or modifying one or more processing steps.

Process simplification VIP provides project teams with suggested steps to explore design and operation of facility for value added opportunity.

Examples of process simplification VIP are:

• Eliminating heating followed by cooling. • Concentration followed by diluting. • Combinations of previously separate reactions.

c. Process simplification VIP objective is to identify plant or facility design that is:

1. Cost effective in producing desired product.

2. Easy, safe, and less hazardous to operate and maintain.

3. In compliance with BP corporate standards and constraints.

4. In compliance with all HSSE laws and regulations

5. Improvement to overall key objectives.

d. Process simplification VIP is applicable to and shall be used by projects of all types and sizes.

e. Before developing project plan, process simplification VIP should be tailored to fit project needs.

f. Process simplification VIP should be applied to projects in structured and consistent approach.



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g. Process simplification VIP requires facilitated workshop varying in time and objectives to meet project needs.

h. Process simplification VIP is most useful and should be applied during appraise, select, and define stages of CVP (see Figure 1).

Figure 1 - Capital value process (CVP)

i. Initial process simplification VIP workshop should be held after preliminary process flow diagrams (PFDs) are developed.

j. Second process simplification workshop may be held after preliminary piping and instrument diagrams (P&IDs) are developed.

6.3.3. Waste minimisation and management VIP

Waste minimisation and management VIP helps project teams consider environmental impact over project lifecycle during planning stages of project.

a. Waste minimisation and management plan shall cover construction, startup, operations, and ultimate dismantling of production equipment or plant.

b. Goal is to minimise total lifecycle cost for environmental protection.

c. Project team should be alert to special situations for protecting environment in accordance with BP corporate goals that may require more than minimal compliance with statutory and regulatory requirements.

d. At project beginning, waste minimisation and management VIP encourages team to:

1. Examine overall organisational responsibilities for environmental activities from regulatory compliance obligations to any additional requirements that might be imposed by terms and conditions contained in legal contracts such as Production Sharing Agreements, Host Country Agreements, Lenders Agreements etc..

2. Define key environmental activities and responsibilities.

3. Assess and develop best management methodology suited to environmental aspects of project.

4. Eliminate waste from process design.

5. Link activities of management team to environmental responsibilities of operations, including existing HSSE management systems.

6. Work with outside agencies to establish environmental standards that will govern both project management team and contractor activities.

Waste minimisation and management VIP proactively addresses environmental issues and opportunities to reduce waste as integral part of design process.

e. Process stream waste minimisation analysis shall be performed on process stream primarily during select stage of CVP to develop concepts that reduce or preferably eliminate each waste stream at source.

f. Practice shall be applicable to all projects (except like for like equipment replacement).

g. Minimisation and Waste Management VIP should be scaled proportional to potential for adverse environmental impact and project size.



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h. Waste Minimisation and Waste Management VIP should be performed during each stage of front end loading (FEL) portion of project.

i. Waste Minimisation and Management VIP shall perform the following steps during each stage of CVP (Figure 2 shows at which stage each step should be considered):

1. Align with business and BP goals.

2. Define geographic area.

3. Identify and categorise waste.

4. Analyse regulations, contractual requirements and other legal issues

5. Minimise and manage waste by looking for alternatives.

6. Select waste management practice.

7. Implement area waste management plan.

8. Review and update waste management plan.

Figure 2 - Waste minimisation and management VIP during CVP

j. The following quality metrics provide indication of how well practice is used:

1. Environmental leadership accountability is established during appraise.

2. Proactive environmental charter, implementation plan, and specific project environmental objectives are established during appraise or early select.

3. Environmental compliance and permitting requirements are identified during select.

4. Team shall document waste management hierarchy of emissions or discharges.

5. Process stream waste minimisation analysis is completed during select or define.

6. For each stream, waste management hierarchy options of source elimination, reuse, and recycle are assessed, with treatment and disposal viewed as last resort.

7. Best environmental practices are applied to manage remaining waste streams.

8. For application enhancements phase, team conducts structured design review during define phase for non routine operations, focused on reducing fugitive emissions and protecting groundwater/overboard discharges.

6.3.4. Other VIPs

Other VIPs to be considered for mitigating risks associated with accidental incidents are:



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a. Design to capacity.

b. Facilities system performance.

c. Technology selection.

d. Value engineering.

e. Setting business priorities.

6.4. Inherently safer design (ISD)

a. Inherently safer design (ISD) guidelines provide structured approach to:

1. Eliminating hazards at source.

2. Minimising risks from hazards that remain.

3. Creating effective hazard management process.

b. ISD is mainly focused towards concept selection or FEL stages (appraise, select, and define).

c. Goal of ISD is to produce inherently safer processing designs for plants and facilities that are simple to operate, more reliable, and have reduced dependence on people and safety systems.

ISD will provide greatest reduction in risk for investment of time and capital.

d. ISD principles and structured approach can be applied to any worldwide facilities that BP builds and operates, including:

1. Gasoline (petrol) stations.

2. Bridges.

3. Offshore platforms.

4. Chemical plants.

5. Producing wellheads.

6. Radically new technology that does not yet have established rules or risk assessment techniques.

ISD principles concentrate not only on reducing risk at source but also include comprehensive information on residual hazard management.

ISD uses proactive structured approach to hazard management during FEL of project, specifically in process design phase.

ISD brings together and depends on many diverse risk assessment and management processes that are implicit in many ETPs, such as process, structural, instruments, and electrical.

ISD processes contribute to overall picture of risk management by supporting implementation of corporate goals in this area.

ISD concepts focus on several key areas, including:

• Overall principles of ISD, similar to IMFS, but highlighting particular design requirements.

• Planning and resource

- ISD document provides guidelines during appraise, select, and define stages of project such that understanding and management of hazards is key input to process design, rather than retrospective assurance process.



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- ISD document highlights several project requirements that must be in place for ISD to flourish, such as contractual relationships that encourage ISD and provision of correct specialised resources during concept selection.

• Concept development and selection

- ISD document encourages generation of different overall processing concepts and their optimisation during appraise and select stages of CVP.

- ISD offers pragmatic process for selection of development options based on residual risk and difficulties in managing hazards that remain.

• Final structured phase of ISD is residual hazard management. Residual hazard management steps are:

- Analysis of cause, severity, consequence, and escalation at beginning.

- Minimisation of characteristics at source.

- Selection of appropriate hazard management strategy for each identified and residual risk to prevent, control, or mitigate risks.

e. Flowchart of ISD hazard management process is shown in Figure 3.

Implementation and assurance of ISD principles are in current BP HSSE processes, such as project HSSE review (PHSSER).

f. HSSE reviews performed in appraise and select stages of project should include inherent safety review.

Inherent safety review uses process flow diagrams and layout drawings, along with other preliminary documentation.

Largest benefit from application of inherently safer design principles can be obtained during appraise and select stages.

g. Hazard management review shall comply with:

1. GP 48-01.

2. GP 24-03.



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Figure 3 - ISD hazard management flowchart

HAZID

HAZARD UNDERSTANDING

Cause Severity Consequence Escalation

MINIMI Z E at SOURCE E LIMINATE

PREVENT

DETECT and

CONTROL MITIGATE

EVAC U A TE

STRATEGY

PASSIVE

ACTIVE

OPERATIONAL

EXTERNAL

SYSTEM

INTEGRITY FUNCTION

COMPETENCE

RELATIONSHIPS

STANDARDS

IS IT GOOD

ENOUGH?

IMPLEMENT

YES

NO

RISK

6.5. PHSSER - HSSE reviews during projects

6.5.1. Project HSSE reviews

a. HSSE reviews of major projects, small capital projects, and turnarounds shall be performed at appropriate times during each CVP stage of project or activity. The HSSE reviews for the projects shall follow the PHSSER requirements in GP 48-01.

b. The PHSSER process requires that 7 HSSE reviews be conducted during the CVP five stage project life cycle, one per stage except for execute which has three, and all projects shall follow the PHSSER process.

6.6. Safer designs using constructability VIP

6.6.1. Merits of constructability VIP

a. Safety in design includes implementation of constructability concepts of merit during define and early execute stages of CVP.

Constructability concepts improve project performance and improve safety by reducing risk of accidents during construction, operation, and maintenance.



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b. Constructability VIP concepts shall be integral part of project execution process.

Constructability is identified as one of the most beneficial VIPs.

Constructability VIP efforts have shown that owners accrue average reduction in total project cost of 4.3% and schedule of 7.5%.

Safety records were also improved.

Savings represent 10:1 return on investment through application of constructability VIP.

Some BP competitors have reported that they achieved up to 70:1 return on invested time and capital.

6.6.2. Constructability definition and activities

a. Constructability VIP is defined as “a systematic method that enables the project team to optimise the use of construction knowledge and experience in planning, engineering, design, procurement, fabrication, and installation to achieve overall project and safety objectives.”

b. Widely accepted definition of constructability from Construction Industry Institute (CII) is “the optimum use of construction knowledge and experience in planning, engineering, procurement, and field operations to achieve overall project objectives.”

In practice, constructability means many different things to many different people.

Constructability VIP definition emphasises “systematic method” for optimising construction knowledge and experience, which means that constructability is a managed work process.

c. Constructability activities to be accomplished, along with roles and responsibilities, are described at “Excellence in Project Management” website: http://projects.bpweb.bp.com/vip/construc/indexcon.htm.

6.7. Safer designs by addressing maintainability and operability

6.7.1. General

a. Design engineers shall take into account safety of personnel who will eventually operate and maintain BP plant or facility during Define and Execute stages of CVP.

b. To ensure personnel safety, design engineers shall refer to ETPs listed in �6.7.2.

6.7.2. Personnel safety ETPs

6.7.2.1. Noise exposure mitigation

a. Many worldwide governmental regulations protect operating personnel in petrochemical industry (and the public) from high noise exposure levels generated by plant and facility equipment and processes.

b. Major noise contributors are:

1. Compressors, gas turbines, pumps, and motors.

2. Other rotating or reciprocating machinery.

3. Gas velocities in piping after pressure letdown valves or devices.

c. To design and procure plant and facility equipment to mitigate noise exposure, projects shall comply with:

1. GP 14-01.



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2. GIS 14-011.

6.7.2.2. Operating access to valves

Projects shall comply with GP 62-01, especially in the operability section.

6.7.2.3. Operating and maintenance access to instrumentation

Projects shall comply with GP 30-25, especially in the maintenance access, instrumentation installation, and location sections.

6.7.2.4. Maintenance access to vessels, towers, and man-ways

Regarding platforms, stairways, and ladders for maintenance access to manholes and to provide escape routing, projects shall comply with:

a. GP 46-01.

b. GP 04-20.

6.7.3. Safer designs for maintenance of equipment

a. Projects shall have means (e.g., beams, monorails, lifting devices, hoists, cranes, removable panels) for equipment maintenance and access.

b. Installations shall have clear overhead pathways (sometimes after removing building or sound enclosure walls) such that pieces of rotating equipment (e.g., compressor cylinders, motors, compressor frames, compressor block valves, pumps, seal pots, fans) can be removed for maintenance or replacement.

c. Projects shall comply with GP 35-10.

6.8. Security in designs

a. Group security policy underpins and establishes basis for how BP manages security globally.

b. Group security policy determines that BP fundamental mission is to provide safe and secure working environment by protecting personnel, assets, and operations against risk of injury, loss, or damage from criminal, hostile, or malicious acts.

c. Security shall be taken into consideration during proposal, planning, and implementation stages of new capital projects.

d. Capital project security support reviews (CPSSR) shall be performed for new capital projects.

e. CPSSR is procedure to ensure security of new construction projects and major renovations of existing facilities.

f. CPSSR methodology provides for:

1. Prior identification of potential security risks.

2. Selection and implementation of security safeguards appropriate to identified risks.

3. Followthrough monitoring of security safeguards that have been implemented.

g. Beginning with appraise stage of CVP, CPSSR shall be used to identify and assess security issues and risks in conjunction with HSSE reviews.

h. Mitigation plans shall be implemented. Mitigations affecting overall design and plant/facility layout shall be incorporated as soon as practical to address identified risks.

i. Projects vary considerably. Distinctly different processes can be found in construction of office buildings, plants, pipelines, retail stores, and extraction facilities on and offshore.



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j. Statements in i. also apply to partial constructions and renovations. Each project will have its own manner of operation and its own set of security risks.

k. More guidance can be found on “Excellence in Project Management” website under project HSSE plan and security at this link: http://projects.bpweb.bp.com/hse/plan/plansec.htm.

6.9. Designing for environmental issues

6.9.1. Introduction

a. Environmental guidelines shall apply to new developments and major modification projects.

b. Objectives are:

1. Consistent federal approach is achieved.

2. Uniform public demonstration of BP environmental commitment is assured.

3. Due environmental process has been followed in developing capital cases for sanction approval.

c. After guidelines are applied, final plant and facility designs should be based on balance of relevant economic and environmental considerations.

Purpose of designing for environmental issues is to ensure that projects and developments strive to achieve corporate goal of no damage to environment in the most cost effective manner. Guidelines explain process that should be followed to establish best achievable environmental performance in project, along with key technical and operational elements that contribute towards final performance level. This is a generic guideline for BP and does not provide specific details or processes to be followed. Guidelines also provide link to CVP.

d. To use guidelines, each project organisation shall develop internal processes that will lead to optimal result, taking into account project specific conditions, such as scope of operation, local environment, local/regional legislation, public perception, and partner buy in.

6.9.2. Overview of process steps

a. Project team should follow recommended steps to ensure that selection of final development concept and chosen technical solutions are performed in the most cost effective manner.

b. Process steps for CVP stages are shown in Table 1.

Table 1 - Environmental design steps

Step Task CVP phase 1 Define project environmental goals, regulatory compliance requirements,

and stakeholder expectations. Appraise

2 Identify no damage base case for final development options. Early select 3 Justify proposed variation from goal of no damage and present project

environmental strategy in DSP. Environmental strategy shall meet regulatory compliance requirements such as allowable permit or license limits.

Select

4 Define minimum damage level based on chosen development concept and final technical solutions, including considerations for remediation.

Early define

5 Ready for sanction approval including remediation recommendations in DSP.

Late define

6 Ensure that decisions made earlier in process are implemented. Execute



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6.9.3. Decision making process

6.9.3.1. Setting goals

a. New BP projects shall strive to deliver exemplary environmental performance onsite, in office, and wherever they have control or influence.

b. Projects shall use zero damage as starting point of decision making process.

c. Damage can be caused by:

1. Emissions to air and water/sea/ground.

2. Physical interactions or nuisance (e.g., visual impact, noise, footprint, odour, dust).

3. Energy inefficiency.

4. Materials use and waste generation.

5. Interference with other users of local environment.

d. To achieve excellent performance and move towards goal of no damage, projects should develop specific goals that form starting point of project development process.

e. Each project should develop its own specific list of relevant goals consistent with no damage to environment.

f. Typical goals are as follows:

1. No flaring or venting.

2. No fugitive emissions.

3. No combustion emissions.

4. Zero discharge of oil or hydrocarbon liquids to land or sea.

5. Zero discharge of chemicals to land or sea.

6. No use of ozone depleting substances.

7. Maximise efficiency of net energy exported.

8. No discharge of drilling fluids or cuttings.

9. Sustainable raw material use.

10. No waste disposal.

11. Total reuse/recycle of facility components at end of lifecycle.

12. Restore habitat after removal of installation.

13. No land disturbance beyond absolute minimum necessary for operations.

14. Acquire land surrounding plant or facility to minimise future public encroachment as protection to public.

15. No nuisance (e.g., visual impact, noise, odour, dust).

16. No interference with other users of local environment.

6.9.3.2. Identify zero damage base case

a. Every project should undertake process to demonstrate how specific environmental goals should be met.

b. Project shall identify and cost zero damage processing base case for plant or facility to be built.



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c. Project process should understand and document technical, economic, and other relevant reasons why project final development option has deviated from zero damage base case.

d. Remediation measures should be fully considered if damage is not eliminated.

e. To establish zero damage case, some considerations of technical issues that should be addressed are in �6.9.3.3. List does not represent complete list of issues to be considered.

6.9.3.3. Variations from goal of no damage

a. Projects that propose variations from project specific goals consistent with no damage to environment shall demonstrate justification process.

b. Project environmental strategy should be prepared on basis of performance level established described in Table 2.

c. Decision making process contains recommended criteria for evaluation as follows:

1. Technical feasibility: On case by case basis, is goal unable to be met due to technical infeasibility? If yes, alternative technical solutions should be considered.

2. Impact on safety: Would meeting goal have significant negative impact on safety? If yes, proposal to vary from goal may be acceptable.



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Table 2 - Environmental decision making process

Environmental goal Examples of issues for new projects and developments

No flaring or venting Design to eliminate routine flaring/venting (e.g., eliminate sources, flare/vent gas recovery system, consider gas export or gas reinjection). Consider options to prevent occurrence of nonroutine and emergency flaring/venting (e.g., high integrity blowdown compressors), although safety implications will be important. Flaring of produced gas during startup should be prevented.

No fugitive emissions Minimise potential emission sources through design (e.g., number of valves, joint types). Select high quality valve components (i.e., low leakage specification), and ensure appropriate maintenance programmes. Recapture fugitives associated with tanker loading/unloading.

No combustion emissions Technical/economic factors may prevent elimination of combustion emissions, but considerations include: Drawing energy from renewable sources. Recovery and sequestration of CO2 to be evaluated. Issues to reduce combustion emissions include: Selection of high efficiency equipment. Optimisation of energy efficiency at operating point. Use of low NOx turbines. Use of CHP such as waste heat recovery. Variable speed drives. Use of low sulphur diesel. Use of low H2S gas.

Zero discharge of oil and hydrocarbon liquids

Reinjection of produced water. Use of collection vessels to retain drains effluent prior to reinjection and to provide for storage if reinjection is offline. If reinjection not feasible, consider step out technology for enhancing gravimetric separation methods.

Zero discharge of chemicals

Recover chemical effluent streams and dispose of through reinjection system. Evaluate use of new materials technology to eliminate need for chemicals. If possible, select low toxicity chemicals.

No use of ozone depleting substances

Only select products or systems that use non ozone depleting substances.

Maximise efficiency of net energy exported

Developing or modelling optimum energy configuration will require balancing energy demands against other environmental considerations (e.g., reinjection of flue gases). Consider available sources of renewable energy (currently limited, but feasible wind, wave, and solar technologies may become available in future). Selection of high efficiency equipment (e.g., gas turbines, motors). Optimisation of energy efficiency at operating point.

No discharge of drilling fluids and cuttings

Consider reinjection of mud cuttings and fluids. If reinjection not feasible, consider retainment, cleanup, and reuse (with minimal disposal onshore).

Sustainable raw material usage

Preferentially select raw materials from sustainable sources, taking into account local economy.

No waste disposal Plan early to eliminate waste. Recycle waste materials if possible. Disposal is final option.

Total reuse of all facility components at end of project life

Incorporate decommissioning into project planning. Design for reuse and transferability wherever possible.

Habitat restoration after removal

Plan for habitat restoration bringing impacted areas back to condition that reflects local conditions. Reseed/replant using indigenous species.

No land disturbance beyond minimum necessary for operations

Minimise working width for pipeline routes. Plan pad layouts to make maximum use of space, keeping total to minimum necessary for operational requirements.

No nuisance (e.g. visual impact, noise, odour, dust)

Screen developments to minimise visual impacts. Plan working times to avoid noise impacts at sensitive times (e.g., evenings, nights). Clad or screen to minimise noise impacts.

No interference with other users of environment

Consult with other users of environment to determine their needs and avoid potential areas of interference. If appropriate and if there is some loss of economic resource value to other users, plan for financial compensation.



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3. Legislation: Does proposal breach current legislation or legislation anticipated within next 5 yr? If yes, proposal may not be acceptable.

4. BP/JV partner policy: Does proposal breach policy requirements of BP, including goals and targets of joint venture (JV) partners policy? If yes, proposal is not acceptable.

5. Good engineering practice: Does proposal breach principles of good engineering practice? If yes, proposal may not be acceptable.

6. Environmental cost factors: How does financial “saving” (sum of reduced Capex, reduced Opex, and increased Revex) gained from deviating from goal compare with environmental cost factor ranges used by BP? Comparison should give good indication of acceptability or otherwise of proposed variation.

7. Reputation issues:

a) Are there reputation issues involved with damage/goal in question? If yes, proposal to vary from goal may be unacceptable.

b) In this context, reputation issues include public, non governmental organisation (NGO) or government interest, and impact on third parties.

c) Expert judgment and managerial input should be used to assess whether proposal is acceptable.

8. Expert judgment: Most environmental issues shall be considered from local/regional point of view. Issues shall be considered using specialist support.

9. Remediation options: Options should be developed to achieve zero net damage (i.e., habitat recreations, CO2 sequestration or joint implementation in remote locations, site restoration).

10. Optimal environmental alternative: Is proposed variation from goal optimum environmental option short of achieving goal?

6.9.3.4. Minimum damage level

a. Minimum damage level shall be defined based on chosen development concept and final technical solution.

Define phase of CVP is step that develops technical definition of chosen concept.

b. During changes in technical definition, proposed damage should be evaluated as in �6.9.3.3.

c. Minimum damage level shall comply with all HSSE laws, regulations, contractual agreements and other requirements associated with the project.

6.9.3.5. Ready for sanction

a. Final project plans should demonstrate process that started with goal of no damage and assessed proposed variations to achieve final technical solutions.

b. Project soliciting funding shall present expected quantified damage levels and other levels of impact, such as land take, visual impact, noise, and odour.

c. This should be collated and summarised in brief report and should be included in DSP for sanction case.

d. Report should include potential remediation options that can be considered as part of sanction process.

e. Despite fact that this process allows project to vary from goal of no damage, performance significantly better than that of existing operations shall be demonstrated.



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6.10. Designing for Compliance

6.10.1. Introduction

a. BP businesses must comply with a variety of HSSE requirements including international treaties and conventions, country/state laws and regulations, regional directives, local ordinances, lender agreements, production sharing agreements, industry commitments and BP standards.

b. Failure to meet these requirements will adversely impact our business, significantly damage our reputation and result in severe civil, administrative and criminal penalties. Individual employees responsible for non-compliance are subject to personal fines, probation, and house arrest and possible prison sentences.

6.10.2. How to put compliance into the design

a. BP businesses shall follow the Global or US HSSE Compliance Framework (Framework).

To help BP businesses reduce their risk of non-compliance with HSSE requirements and create an enhanced culture of integrity, Group Compliance & Ethics (GC&E) established a Global and US HSSE Compliance Framework (Framework) as a cornerstone of Project Emerald, BP’s global HSSE compliance enhancement project.

b. BP employees in positions of authority shall know and implement the Framework.

c. BP engineers as part of their designs shall design for compliance and should use the tools and Implementation Guidance documents available from GC&E.

Please refer to the GC&E HSSE Compliance web site at http://hssecompliance.bpweb.bp.com/Default.aspx?tabid=155 for more information.

6.10.3. Basic Rules to follow

a. As stated in the BP Code of Conduct, BP employees must always:

1. Comply with the requirements of the HSSE management system at your work location – including the use of relevant standards, instructions and processes – and with the golden rules of safety.

2. Take responsibility for ensuring that our products and operations meet applicable government and company standards, whichever are more stringent

b. Any deviations to following the Framework(s) must be reviewed and approved by the GC&E HSSE Compliance Team; Engineering Authorities are not authorized to make any changes.

7. Loss prevention and risk control

7.1. Purpose

Despite excellent safety record of BP petrochemical plants and facilities and even as the principles of safety in design described above are implemented, accidents may happen.

There is always possibility that accidental release can occur, resulting in fire or other hazardous events during processing, storing, handling, and transferring of flammable materials.

In addition to fire and explosion hazards, accidental release can pose health and environmental risks.

If accident occurs, consequences can be minimised through active and passive interventions.



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a. BP approach to HSSE loss prevention is to design plants and facilities that comply with:

1. Country and local standards and regulations.

2. Project designated codes.

3. Good engineering practices and standards worldwide.

b. Good engineering practices shall be provided by STPs that are consistent with ETPs based on worldwide recognised external industry standards, such as ISO and API.

7.2. ETPs for design

a. Engineered systems, including mechanical, electrical, control, lifting, and structural, shall be designed, procured, constructed, operated, inspected, tested, and maintained in accordance with STPs to ensure that equipment is fit for service, avoids loss of containment, and maintains structural integrity for expected lifecycle of facility.

b. New plant designs shall minimise risk at source and consider best available technology to improve integrity.

c. BP locations and projects shall use STPs that are consistent with ETPs to provide inherent, passive, active, and remediation risk reduction.

d. Differences between STPs and ETPs shall be justified and subject to approval by appropriate engineering authority based on specific local requirements.

BP group technology developed ETPs beginning in 2001 and ending in 2005. ETPs were developed using heritage information from mainly BP, Amoco, and Arco and based on external worldwide industry standards and good engineering practice. ETPs are intended to replace heritage specification sets. ETPs allow business units and projects sufficient flexibility to create site specific supplements to group ETPs. Segment level ETPs and supplements are also allowed. For more information on ETPs, read the ETP introduction document located in the ETP Library #00 category.

ETPs are divided into 45 different categories. The 420+ GPs and GISs cover design of engineered systems, including mechanical, electrical, control, instrumentation, lifting, and structural. ETPs provide inherent and passive safety in design for BP plants and facilities. ETPs also provide engineering guidance on active and remediation safety design alternatives. The Index of ETP categories and Published ETP Documents can be found at http://etp.bpweb.bp.com/.

e. ETPs and STP supplements used on BP projects shall mitigate risks associated with hazards identified through HSSE reviews and mentioned specifically in �7.3 through �7.6.

7.3. Mitigation of fire related hazards

7.3.1. General

a. BP plant or facility shall have fire hazard management philosophy that is developed during late select stage of CVP and finalised during define and early execute stages.

b. Philosophy shall lead to development of fire and explosion hazard management plan (FEHMP) that is agreed upon with plant or facility operator and fully documented. The FEHMP is described in GP 24-10 and GP 24-20.

7.3.2. Fire protection ETPs to mitigate fire related hazards

For mitigation of fire related hazards:

a. Offshore facilities shall comply with GP 24-20.

b. Onshore plants and facilities shall comply with GP 24-10.



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GP 24-20 and GP 24-10 provide guidance to determine:

• Fire hazard management philosophy. • Hazard identification. • Selection of fire hazard management strategy using design fire cases. • Hazard quantification. • Hazard minimisation and control. • Protection and mitigation methods.

The following paragraphs speak generally about different fire scenarios that GP 24-20 and GP 24-10 address.

Hydrocarbon leak or spill can result in accumulation of flammable liquid on ground with formation of flammable vapour. Risk is most pronounced with LNG. Ignition of generated flammable vapour will result in pool fire. Equipment and structures directly contacted with flame plume can be severely damaged or destroyed. If duration of exposure is sufficiently long, equipment and personnel remote from fire may also be damaged or injured by radiant heat emitted by flame.

If leak or spill is not immediately ignited, generated vapour will mix with surrounding air forming flammable vapour cloud that travels downwind. If ignition source is then encountered, vapour cloud can ignite and flame will propagate within vapour cloud. This can cause additional fire, but in general, damage to equipment is limited because duration of exposure to flame is relatively short.

Injury to personnel, on the other hand, can be significant, because heat intensity of exposure can be severe despite of short duration. Given adverse conditions, propagation of flame front can accelerate and produce blast overpressure wave, causing damage, injury, and fatalities on wide scale. Actual consequences would vary depending on gas composition and degree of congestion in facility.

Leaked flammable gas or vapour can migrate into buildings, shelters, or other enclosures if they are not pressurised. Should ignition occur in such enclosures, explosion is possible, resulting in catastrophic damage of enclosure. This is reason for severity rank of LNG spill in enclosed areas.

If flammable liquid is released from pressurised containment, leak may form spray of mist and vapour, as well as liquid phase. If ignited, torch fire is generated. Such fires can also result from release of pressurised gas or vapour. Torch fires present same type of hazards as pool fires. Direct contact with flame and exposure to radiant heat will cause damage to equipment and structures.

Boiling liquid expanding vapour explosion (BLEVE) is catastrophic failure of pressure vessel as result of fire exposure. If pressure vessel contains flammable liquid, BLEVE accompanies with fireball. Because energy from fireball is released in short duration, typically 1 s to 20 s, fireball tends to be large in size with high level of radiant heat fluxes affecting much wider area than if fuel is slowly burned in ordinary pool fire. In addition to fireball, another potentially devastating consequence of BLEVE is blast pressure with shell fragments of ruptured vessels that can be blown far and wide.

Fire control of LNG spill fires can be achieved by application of high expansion foam. High expansion foam is not expected to extinguish such fires, but by forming insulating blanket between base of flame column and LNG pool surface, radiant and convective interchange will be dramatically reduced. This, in turn, will reduce rate of LNG vapourisation and size of flame column. High expansion foam is applied to LNG spill collection basins to shield cryogenic liquid from solar radiation and wind.



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Active and passive techniques will be employed to control dispersion of vapours evolved from liquefied gas spills or leaks and to minimise downwind distance required for vapour clouds to attain lower flammability limit (LFL).

7.3.3. Blast overpressure

To mitigate risks associated with blasts, location and design of temporary and permanent occupied buildings subject to blast loading or overpressure shall comply with GP 04-30.

Ignition of flammable vapour cloud will result in flame front that will propagate back to leak source if flammable portion of cloud is continuous. Blast overpressures are of particular concern because damage to equipment, injury, and death can occur at relatively low levels of blast pressure.

7.3.4. Plant layout and spacing

a. To reduce risks in onshore plants and facilities, spacing between fire potential equipment and structures, buildings, and other piping and equipment shall comply with GP 44-10.

b. GP 44-10 use shall begin in Define Stage of CVP.

Qualitative risk matrix (QRM) could be used to judge seriousness of scenario and provide guidelines for acceptance with or without changes. QRM will allow project team to rank perceived hazards such that most serious hazards are addressed first. QRM will provide formal mechanism for accepting minor (low risk) hazards without further mitigation.

c. Offshore installations shall comply with:

1. Applicable country codes and standards.

2. Applicable exploration and production segment ETPs.

7.3.5. Electrical area classification

For electrical area classification issues, projects, plants, and facilities shall comply with GP 12-60, GP 44-60, and GP 44-65.

Electrical area classification is designed to avoid electrical based source of ignition in area if there could be flammable vapours. Area classification serves as fire and explosion prevention by keeping potential sources of ignition separate from potential flammable vapours. This is passive reduction of probability of event.

If permanent sources of ignition are restricted in certain areas of process plant, such areas should be thoroughly tested for presence of flammables before temporary (portable) sources of ignition are brought in (e.g., during maintenance).

7.3.6. Pressure relief and flare design

a. Flare systems shall be designed in accordance with GP 22-20.

b. Flare systems shall be procured in accordance with GIS 22-201.

Flare design in GP 22-20 is based on API 537.

c. Pressure relieving and disposal systems shall comply with GP 44-80.

Pressure relieving design is based on API 520 and API 521.

7.3.7. Overpressure protection systems

a. Overpressure protection systems in equipment and piping shall comply with GP 44-70.

b. Engineering design and guidance on depressurisation:

1. Shall comply with GP 44-25.



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2. May also use GP 44-80.

Overpressure in equipment and piping can be caused by variety of reasons. Mechanically related ETPs are used to inherently and passively mitigate and prevent ruptures. Rupture can cause:

• Propelled fragments of equipment and piping. • Uncontrolled release of hazardous materials to environment. • Release of hydrocarbons causing fires and possible explosions.

Depending on conditions of fire exposure, conventional safety relief valves may not prevent catastrophic rupture of pressure vessels.

7.3.8. Emergency shutdown and depressuring

a. Emergency shutdown (ESD) system shall be designed to bring entire plant or selected sections into safe shutdown condition for process upset or other emergencies.

b. ESD shall:

1. Be implemented in safety instrumented system (SIS).

2. Comply with GP 30-76 and GP 30-80.

c. Emergency depressuring system shall be provided and shall:

1. Comply with GP 44-25.

2. Have the following functions:

a) Minimise uncontrolled release of flammable or toxic gases.

b) Minimise fuel inventory that would otherwise sustain fire in event of ignition.

c) Prevent catastrophic rupture of pressure vessel in event of fire exposure.

7.4. Hazard detection and alarm signalling

a. Fire and gas detection systems as components of SIS shall comply with:

1. GIS 30-801.

2. GIS 30-851.

3. GP 30-75.

4. GP 30-76.

5. GP 30-80.

6. GP 30-81.

7. GP 30-85.

To mitigate adverse effects of release, it is imperative that release be detected as quickly as possible. Automatic hazard detection devices will be installed in plant or facility to sense low temperature (e.g., cryogenic spill), toxic fumes (e.g., H2S), combustible gas, smoke, heat, fire, and presence of flame radiation.

Fire and gas interlocks are initiated by automatic hazard detection devices and are normally part of SIS. Interlocks normally initiate combination of equipment shutdowns, firefighting activities (e.g., water deluge and foam production), and audible and visual alarm notification devices (e.g., sirens, horns, beacons).

b. Manual alarm stations

1. Unless required otherwise, manual alarm pull stations shall be installed throughout plant or facility.



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2. Manual alarm locations shall have high visibility and accessibility without requiring excessive travel distances.

3. Manual alarm pull stations shall be grouped into zones for purpose of initiating ESD, starting firewater pump, and alarm annunciation.

c. Audible and visual alarm devices (e.g., recorded verbal messages, sirens, horns, and strobe lights) shall be installed throughout plant or facility to draw attention to emergency public address announcements or to hazardous condition.

7.5. Toxic hazards and oxygen deficient atmospheres

a. BP sites and projects shall determine risks to plants, facilities, and personnel associated with toxic inhalation and toxic exposure to skin.

b. Systems, processes, and physical facilities shall be implemented to manage risks associated with unwarranted release of identified toxic gases and substances.

c. Toxic hazards shall be managed to:

1. Preserve life.

2. Minimise injury.

3. Minimise personnel exposure.

4. Protect plant equipment and systems.

5. Limit business losses.

d. Special attention shall be placed on detecting and alarming oxygen deficiency of enclosed spaces, such as small buildings or analyser houses.

Most hydrocarbons in BP plants and facilities can be classified as simple asphyxiants. Materials, such as acids, caustics, and hypochlorites, present more serious exposure concerns. Exposure to gaseous hydrogen sulphide (H2S) and sulphur dioxide (SO2) can be serious, particularly if concentrations exceed threshold limit value (TLV) - time weighted average (TWA) or permissible exposure limit (PEL).

TLV refers to airborne concentrations that correspond to conditions where no adverse effects are normally expected during a human lifetime. Exposure occurs only during normal working hours, 8 hr/d and 5 d/week. Excursions above limit are allowed if compensated by excursions below limit. TLV-TWA or PEL values refer to American Conference of Governmental Industrial Hygienists (ACGIH) indices.

H2S has TLV/TWA of 10 ppm (volume). H2S is irritant to moist human tissues. Irritation of eyes and respiratory organs at concentration above 20 ppm (volume) increases with increased concentration and the duration of exposure. Greatest health risk associated with inhalation of H2S is acute effects. Effect is not cumulative. H2S is of greatest concern in exploration and production segment and in refineries.

Oxygen deficiency continues to be significant threat to BP personnel, especially if nitrogen is used to purge equipment, piping, and instrumentation. Nitrogen gas is not detectable by odour like H2S. A person first becomes aware of this when he has totally lost his breath. At that moment, it may be too late.

Hypochlorites have moderate toxic hazard through skin irritation, ingestion, and inhalation. If heated or contacted with acid or acid fumes, they will emit highly toxic fumes of chlorine and chlorides.

Cryogenic hazards: LPG and LNG present hazards to plants and facilities due to subzero boiling points. LNG is stored and transferred at boiling point,



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approximately -160 ºC (-256ºF). Unprotected personnel can receive severe freeze burns should they come into contact with LPG, LNG, or liquid nitrogen. In addition, many structural or plant materials, such as ordinary carbon steels, may fail due to brittle fracture if exposed to liquid at cryogenic temperature. Ordinary carbon steels, for example, behave in brittle manner rather than ductile manner at temperatures below -40 ºC (-40ºF). Carbon steel can be protected against cryogenic exposure by encasement in concrete or other suitable coating materials.

7.6. Hydrocarbon and toxic spill mitigations

7.6.1. Design spill

BP plants and facility design spills shall be determined for each potential hydrocarbon liquid or toxic liquid hazard.

Design LNG spill drainage and containment has been established in accordance with following codes and standards:

• API STD 2510. • NFPA 59A.

Minimum design spill per each area is described below:

• LNG process train: Equipment that can be sources of liquid spill shall be selected considering fluid characteristics and process conditions. Design spill from equipment selected shall be defined as sum of:

- Liquid volume of single accidental leakage for 10 min.

- Liquid volume held inside equipment and/or piping blocked by shutoff valves.

- In calculating liquid release rate, vapourisation of liquid due to heat absorption from atmosphere and ground shall not be taken into consideration, although flash vapourisation due to discharge of pressurised liquid into atmosphere can be taken into consideration.

• LNG storage: For LNG tank without side penetration below liquid level, design spill can be defined as liquid volume releasing from single discharge line in tank pump at design flow rate for 10 min based upon demonstrable surveillance and shutdown provisions in accordance with NFPA 59A, neglecting vapourisation.

• LNG loading platform: Single LNG loading arm is considered as source of liquid spill at loading platform. Design spill from single loading arm can be defined same as that for LNG process train.

• Refrigerant storage: According to API STD 2510, design spill can be defined as follows: For pressurised LPG vessel, liquid volume at least 25% of largest vessel or at least 50% of largest vessel if vapour pressure is less than 100 psi (absolute) at 100º F.

7.6.2. Spill quantity minimisation

BP plants and facilities shall have appropriate emergency shutdown valves, emergency release couplings, pump trips, and other devices to minimise potential hydrocarbon liquid and/or toxic liquid spills.

To reduce material loss during spill, it is essential that spill is detected quickly, equipment feeding material is shut off, and leak is isolated from material source. Consideration should be given to having manual intervention to implement shutdown of equipment and processes. In this case, spill detectors (e.g., combustible, level, low temperature, or other typical detection devices) detect hazardous



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substance spill. After actuation of and alarming of detection devices, operator determines if manual shutdown of operations is justified based on prior conceived hazard mitigation plans.

7.6.3. Spill drainage and containment

a. Spills shall be contained and preferentially drained by curbs, trenches, channels, and sumps.

b. Fixed hazard control equipment shall be installed at spill impounding areas.

c. Spill containment shall comply with GP 04-10 and GP 04-20.

For any given quantity of design liquid spills, hazards of spill can normally be decreased if area over which liquid spreads is minimised. Therefore, liquid should be contained in small area.

Although most of these methods are appropriate for refrigerated liquefied gases, spill drainage and containment can also be applied to pressurised liquefied gases. Some techniques are based on reducing effects of variables that influence boiloff from refrigerated liquefied gases and vapour cloud formation. For example, spill drainage trenches are designed consistent with design spill rates to minimise wetted perimeter. Trenches shall also have holdup weirs to delay refrigerated liquids from contacting warm substrate.

Low density insulating concrete or other materials in containment areas can markedly reduce rate of heat transfer to LNG or LPG liquid spill and should be considered. Spills are drained and contained to limit heat input from environment to liquid spill.

d. Plant or facility maintenance program shall ensure that sand and other debris is periodically removed from drainage trenches and containment basins, particularly those serving refrigerated liquefied gases.



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Bibliography

American Conference of Governmental Industrial Hygienists (ACGIH) [1] Threshold Limit Values and Biological Exposure Indices.

American Petroleum Institute (API) [2] RP 520, Part 1, Sizing, Selection, and Installation of Pressure-relieving Devices in Refineries.

[3] RP 521, Guide for Pressure-Relieving and Depressuring Systems.

[4] STD 537, Flare Details for General Refinery and Petrochemical Service.

[5] STD 2510, Design and Construction of LPG Installations.

National Fire Protection Association (NFPA) [6] 59A, Standard for the Production, Storage, and Handling of Liquefied Natural Gas (LNG).