sp1075

HEALTH, SAFETY AND ENVIRONMENT SPECIFICATIONFire and Explosion Risk Management

DOCUMENT ID - SP 1075REVISION - 2.0DATE - - 15/07/02

HSE – SPECIFICATION Setting Clear Requirements

SP-1075 REVISION 2.0 Page ii

Authorised for Issue by the HSE IC 15/07/02

Document AuthorisationDocument Authority Document Custodian Document Author‘dapo OguntoyinboRef. Ind: CSMDate: 15/07/02

Hamad KhalfeenRef. Ind: CSM/11Date: 15/07/02

Hamad KhalfeenRef. Ind: CSM/11Date: 15/07/02

The following is a brief summary of the four most recent revisions to this document. Details of all revisions prior to these are held on file by the Document Custodian.

Version No. Date Author Scope / RemarksRev 2.0 June 2002 Hamad Khalfeen Editorial changes, new formatRev 1.0 July 1998 Updated to Incorporate Fire & Explosion

StrategiesRev 0.0 March

1990Original issue as ERD 88-02

User Notes:

The requirements of this document are mandatory. Non-compliance shall only be authorised by CSM through STEP-OUT approval.

A controlled copy of the current version of this document is on PDO's EDMS. Before making reference to this document, it is the user's responsibility to ensure that any hard copy, or electronic copy, is current. For assistance, contact the Document Custodian.

This document is the property of Petroleum Development Oman, LLC. Neither the whole nor any part of this document may be disclosed to others or reproduced, stored in a retrieval system, or transmitted in any form by any means (electronic, mechanical, reprographic recording or otherwise) without prior written consent of the owner.

Users are encouraged to participate in the ongoing improvement of this document by providing constructive feedback.


Contents

1.0 INTRODUCTION.............................................................................................5

1.1 PURPOSE......................................................................................................51.1.1 Objectives............................................................................................5

1.2 SCOPE..........................................................................................................51.3 DEFINITION....................................................................................................61.4 DELIVERABLES...............................................................................................61.5 ROLES AND RESPONSIBILITIES...........................................................................61.6 PERFORMANCE MONITORING.............................................................................61.7 REVIEW AND IMPROVEMENT..............................................................................71.8 REPORTING FORMAT........................................................................................7

2. PERFORMANCE REQUIREMENTS.......................................................8

2.1 BASIS...........................................................................................................82.2 ROLE OF PRE-FIRE PLANNING IN SYSTEM DESIGN.................................................92.3 FERM ENGINEERING AND DESIGN PRINCIPLES......................................................92.4 APPLICATION OF FIRE AND EXPLOSION STRATEGIES DURING DESIGN.......................10

2.4.1 Modifications to Existing Facilities.....................................................102.4.2 Green Field Facilities..........................................................................10

3.0 DETECTION AND PROTECTION REQUIREMENTS.............................13

3.1 GENERAL....................................................................................................133.1.1 Fire Proofing of Supporting Structures...............................................13

3.2 HYDROCARBON HANDLING FACILITIES...............................................................133.2.1 Wellheads..........................................................................................133.2.2 Oil/Gas Inlet Manifolds.......................................................................133.2.3 Gathering, Production Stations & Storage Tanks...............................133.2.4 Gas Processing Facilities....................................................................213.2.5 Booster Stations.................................................................................22

3.3 UTILITY FACILITIES........................................................................................233.3.1 Power Stations...................................................................................233.3.2 Control and Auxiliary Rooms..............................................................233.3.3 Electrical Substations and Switchgear Rooms....................................23

3.4 OFFICE BUILDINGS, RESIDENTIAL AND INDUSTRIAL AREAS....................................233.4.1 General..............................................................................................233.4.2 Plans and Procedures.........................................................................243.4.3 Office Buildings..................................................................................243.4.4 Residential Areas...............................................................................253.4.5 Industrial Areas..................................................................................25

3.5 AIRSTRIPS...................................................................................................263.5.1 Aircraft rescue and fire fighting.........................................................263.5.2 Mobile Equipment..............................................................................263.5.3 Air strip buildings...............................................................................26

4.0 DETECTION SPECIFICATIONS.......................................................27

4.1 DETECTION SYSTEMS.....................................................................................274.2 GAS DETECTION...........................................................................................27

4.2.1 Flammable Gas Detection Philosophy................................................274.3 FIRE DETECTION...........................................................................................28

4.3.1 Optical Flame Detection.....................................................................284.3.2 Bimetallic Heat Detection..................................................................284.3.3 Fusible Plug Heat Detection...............................................................284.3.4 Fusible Link Heat Detection...............................................................284.3.5 FQB Heat Detection...........................................................................29

SP-1075 REVISION 2.0 Page iii


4.3.6 Smoke Detection...............................................................................294.4 AUDIBLE, VISUAL AND MANUAL ALARM CALL POINTS...........................................30

4.4.1 Hydrocarbon Handling and Utility Facilities.......................................30

5.0 FIRE PROTECTION SYSTEMS........................................................31

5.1 FIRE WATER SYSTEMS...................................................................................315.1.1 Fire Water Network – General............................................................315.1.2 Fire Water Storage Tank....................................................................325.1.3 Fire Water Pumps..............................................................................325.1.4 Hydrants............................................................................................325.1.5 Monitors.............................................................................................33

5.2 WATER APPLICATION SYSTEMS........................................................................335.2.1 Sprinkler Systems..............................................................................345.2.2 Waterspray (Deluge) Systems...........................................................34

5.3 FOAM SYSTEMS............................................................................................355.3.1 General..............................................................................................355.3.2 Foam Concentrate.............................................................................355.3.3 Foam Proportioning Systems.............................................................375.3.4 Foam Application Systems/Equipment...............................................395.3.5 Foam Deluge Systems.......................................................................455.3.6 Portable Foam Application Equipment...............................................45

5.4 FINE WATER SPRAY SYSTEMS..........................................................................465.5 GASEOUS EXTINGUISHING AGENT SYSTEMS........................................................465.6 PORTABLE EXTINGUISHERS.............................................................................46

5.6.1 General..............................................................................................465.6.2 Standards for Portable Fire Extinguishers..........................................46

6.0 ALARMS AND EXECUTIVE ACTIONS..............................................47

6.1 GENERAL....................................................................................................476.2 GAS TURBINES.............................................................................................47

7.0 ABBREVIATIONS.........................................................................49

8.0 REFERENCES..............................................................................51

APPENDIX A - RELEVANT STANDARDS, SPECIFICATIONS & CODES.................52

APPENDIX B - ASSESSMENT OF BUSINESS RISK DUE TO FIRE AND EXPLOSION. 56

APPENDIX C - FACILITY GROUP CATEGORIES.............................................57

APPENDIX D - TYPICAL ALARMS AND EXECUTIVE ACTIONS...........................59

APPENDIX E - WORKED EXAMPLES..........................................................64

SP-1075 REVISION 2.0 Page iv


1.0 Introduction

1.1 Purpose

This Specification provides users with a standard specification for the level of fire and explosion mitigation measures that are tailored to typical facilities in PDO.

This document incorporates the latest international standards, DEP’s and the EP 95-0000 guidelines dealing with fire protection. In addition, this Specification incorporates the findings and recommendations from three fire protection related studies, namely:

The Halon Phase Out Study (Reference 2) The Fire Protection Study (Reference 3) Review of Emergency Services at PDO Airfields (Reference 5)

The studies established the actual risk from fires and explosions in PDOs facilities and have determined the appropriate level of control to mitigate the consequences in the event of a fire/explosion using QRA and Cost Benefit Analysis.

This Specification should be used to assist engineers define the appropriate fire and gas detection and protection equipment, where there is a wide range of size and criticality of equipment (e.g. shipping pumps and cone roofed storage tanks) that deviates from the typical. The Specification describes a simple methodology that is appropriate to the level of business risk of the facility concerned.

Reference is made in this Specification to the FERM Facility Plan Guideline, GU 230 (Reference 6), which provides additional information in applying the standards.

1.1.1 Objectives

This Specification has the following objectives, to:

Establish the appropriate level of protection against fire and explosion hazards which are appropriate to the level of business risk in PDO.

Arrive at consistency in risk classification of similar types of facilities

Arrive at consistency in equipment Specification for gas/fire detection and fire fighting equipment

Focus maintenance and pre-fire planning efforts for the most critical pieces of equipment

Provide an auditable approach to fire and explosion risk management of individual facilities, which can be readily adapted when these are modified or when conditions such as production levels or equipment criticality change

1.2 Scope

This Specification covers the requirements for fire and gas detection and protection in PDO facilities. These requirements shall be applied when making plant modifications and when designing new facilities.

SP-1075 REVISION 2.0 Page 5


The Specification covers both green field facilities and modifications to existing plant. Due consideration to cost effectiveness shall be taken into account when applying these standards to existing facilities, particularly over the remaining plant life. The scope of the Specification also includes the preparation of a fire response document pertaining to the facility being designed or modified and the incorporation of these in the relevant operational documents. The approach is in line with EP 95-351, Fire Control and Recovery.

1.3 Definition

This Specification draws upon a number of relevant international sources to define the requirements for management of fire and explosion risks. Where a user is referred to another standard, the latest edition of the relevant standard shall be used. In the event of discrepancies between sources, the order of precedence shall be:

1. This Specification & other PDO standards referred to in this Specification2. SIEP DEP’s3. International Standards4. EP95000 series publications

A reference list of all the standards, specifications and codes used throughout this document is provided in Appendix A.

This Specification also relies on the use of a large amount of acronyms and abbreviations that may not be familiar to personnel who don’t have experience in fire protection. A glossary of terms is provided in Section 7 of this Specification to aid in the understanding of personnel unfamiliar with any terms used within.

1.4 Deliverables

1.4.1 RecordsRecords produced as a result of the use of this Specification will be incorporated into design documentation and the FERM Facility Plan.

1.4.2 ReportsPDO Staff: Any non-compliance with this Specification shall be notified, investigated and reported as per CP 122 HSE Management System Manual, Part 2, Chapter 6.

Contractors: Any non-compliance with this Specification shall be reported to the Contract Holder.

1.5 Roles and Responsibilities

Asset Managers

Asset Managers are responsible for ensuring that they do accept new or upgraded facilities that re not in compliance with this Specification.

Design Engineers

Design Engineers are responsible for the implementation of the requirements provided in this Specification.



1.6 Performance Monitoring

Compliance with this Specification shall be monitored through workplace supervision, periodic site inspection and design reviews such as hazard and operability (HAZOP) studies.

1.7 Review and Improvement

Any user of this document who encounters a mistake or confusing entry is requested to immediately notify the Document Custodian using the form provided in CP 122 HSE Management System Manual, Part 2, Chapter 3.

This document shall be reviewed as necessary by the Document Custodian, but no less than every four years. Triggers for full or partial review of this Specification are listed in CP 122 HSE Management System Manual, Part 2, Chapter 8.

1.8 Reporting Format

There are no routine reporting requirements pertaining to this Specification.



2. Performance Requirements

2.1 Basis

The risks due to fire and explosions of existing typical assets in PDO were assessed using a ‘Risk Matrix’ (see Appendix B). This was used to rank the relative risk to the various types of facilities and illustrates the rationale of the decisions taken at that time. Based on this evaluation, four different strategy levels for addressing fire and explosion incidents within PDO have been developed. These are defined as:

Strategy 1 Minor Incident Intervention OnlyResponse limited to trained personnel using portable extinguishers or other types of first aid fighting equipment (hand-held or mobile). In addition, in critical areas such as some areas of camps, automatic detection systems may be provided to provide fast alarm and personnel escape.

Strategy 2 Dedicated Fixed Fire Protection System

Automatic actuation of a self-contained extinguishing system for a specific facility from detection systems.

Strategy 3 Systems/Equipment plus Back-UpDedicated fixed fire protection systems and a firewa6ter network with back up from manual intervention by trained personnel using fire fighting equipment.

Strategy 4 Systems/Equipment plus Fire Brigade

Similar to Strategy 3 with back up from a professional fire brigade.

Using these four strategies, typical PDO facilities can be categorised and grouped together with a common approach for defining fire and gas detection and protection. For a facility group, e.g. a gathering station, the applicable strategy has been determined through consideration of the typical equipment contained within that facility group.

Figure 2.1 shows the four basic strategies and the facility groups contained in each strategy. The figure also highlights the risk drivers associated with a facility group. It should be noted that because of the onshore location of PDO facilities, low manning levels at most facilities and the generally unconfined layout, life safety is generally not the dominant risk driver.

Although this is a very coarse delineation of required control and recovery systems, it does provide a high level overview. The prime objective is to optimise the level of risk contributed by each type of equipment to meet the FERM requirements.

Due to the variation between PDO gathering and production stations these have been categorised into different types, (A, B, C etc.) and have been assigned different strategies. The assigned Facility Group Categories are shown in Appendix C.



Figure 2.1: FERM Facility Group/Strategy Matrix

2.2 Role of Pre-Fire Planning in System Design

Pre-fire planning addresses the nature of contribution from human intervention and systems as a recovery measure. For the purposes of PDO these shall be in the form of a FERM facility plan. FERM facility plans pertaining to the facilities shall be prepared (or updated for existing assets) as part of the project. Such a plan shall describe the appropriate fire and explosion strategy, identify the main risk drivers, identify the station category type (if applicable) and prepare scenario based pre-fire plans for inclusion in the emergency response documentation pertaining to the facility.

The content and guidance in the preparation of such plans can be found in GU 230 FERM Facility Plan Guideline.

2.3 FERM Engineering and Design Principles

The business risk due to fire and explosions in PDO shall be determined by a combination of the following risk drivers:

Life safety Damage to the environment Lost and deferred production Loss of assets (facility) Reputation



Fire and explosion risk reduction measures shall be prioritised in the following order:

1. Prevention and probability reduction by process selection and design

2. Detection of gas and fire incidents and alarm to personnel3. Mitigating measures to prevent escalation of the incident by

shutdown, plant design and layout4. Damage mitigation by passive protection5. Damage mitigation by automatic fire protection systems6. Damage mitigation by manually operated fire protection systems 7. Damage mitigation by manual fire fighting response.

2.4 Application of Fire and Explosion Strategies During Design

2.4.1 Modifications to Existing Facilities

The impact of the planned modifications on the current fire and explosion strategy shall be determined during the conceptual design phase of the particular facility modification project. In the event that such modifications include the addition or removal of equipment which changes the fire and explosion risk significantly, the requirement to up or down grade the current station category type and strategy shall be determined.

If a change of category type or strategy is warranted, the impact of the revised strategy shall be determined on the whole facility. In the event of uncertainty, the appropriate category type or strategy shall be determined by QRA studies in accordance with EP95-0352, Quantitative Risk Assessment. The resulting hardware changes to existing fire protection equipment, future operational fire response requirements, and documentation shall be addressed as part of the project and the FERM Facility Plan amended as required.

A flowchart of the methodology for modifications is provided in Figure 2.4.1.

2.4.2 Green Field Facilities

The appropriate fire and explosion station category type and strategy pertaining to the facilities shall be determined during the conceptual design phase of the project. In the event that none of the existing category types or strategies above are applicable, a new strategy shall be developed and approved as a variation to this Specification, in accordance with the technical authorities system, ERD-00-02.

The new strategy shall be supported by QRA studies in accordance with EP 95-0352, Quantitative Risk Assessment.

A flowchart of the methodology for green field facilities is provided in Figure 2.4.2.



FIGURE 2.4.1

FIRE PROTECTION STRATEGY

MODIFICATIONS

No Change

yes

no

Do the mofications change the

station category?

Asses the impact of revised strategy on whole facility (use

QRA if appropriate)

Conceptualdesign

Up or down grade the FERM strategy

Amend FERM Facility Plan

Do the modifications change the

existing strategy?

Assess impact onexisting fire and

explosion strategy

yes

no



FIGURE 2.4.2

FIRE PROTECTION STRATEGY

GREEN FIELD FACILITIES

Is strategy level covered by

specification?

Conceptual design assess fire risks

Develop fire scenarios

QRA

Determine strategy level

Obtain approval from CSM for new

strategy level

FERM Facility Plan

Incorporate into emergency procedures

Proceed with design of fire

protection system



3.0 Detection and Protection Requirements

3.1 General

This section identifies the requirements for the various types of fire and gas detection and protection equipment for each of the major types of location and production facilities.

Appendix D – Typical Alarms and Executive Actions, summarises the general levels of detection and protection for generic equipment types that are required to meet the fire and explosion strategies for typical facilities. These tables provide an overview only and the engineer shall determine the applicability of the standard protection levels proposed in this Specification when the facilities being designed deviate significantly from other common PDO facilities.

Specific engineering & design details for the detection and protection systems are given in Sections 4 and 5 of this Specification.

3.1.1 Fire Proofing of Supporting Structures

In the event that the design involves elevated process equipment, fire proofing of supporting structures shall be provided in accordance with DEP 34.19.20.11, General Fire Hazards and Fire Proofing. Fire proofing shall not be considered as a replacement for active fire protection requirements nor lead to a relaxation of normal design requirements. The costs for fire proofing can be significant and therefore each case should be considered for the assessment of the likely maximum fire duration and possible escalation.

3.2 Hydrocarbon Handling Facilities

3.2.1 Wellheads

Generally, no fire or gas detection shall be provided for wellheads. However, heat detection shall be provided on wellheads fitted with actuated ESD valves, SSVs, SCSSVs and ESPs and upon fire detection, the valves shall close or pumps shutdown.

3.2.2 Oil/Gas Inlet Manifolds

The overall strategy for both remote and on-plot production manifolds is level 1 - minor incident only.

Generally no fire or gas detection shall be provided for manifolds.

3.2.3 Gathering, Production Stations & Storage Tanks

The categories for existing production and gathering stations have been defined in Appendix C, and have been based on the combination of facilities present at a particular site. Figure 3.2.3 (a) defines the strategy levels. Gathering stations are generally either level 1 or 2, and production stations are typically level 2 or 3. The equipment in these facilities includes: compressors, gas turbine drivers, pressure vessels, fuel gas skids, fired furnaces, cone and floating roofed tanks, and pumps. The following sections give the general protection requirements for such equipment.



For strategy 3 facilities, consideration shall be given to the installation of flame detection.



Production and Test Separators

Generally no detection is required for crude oil separators, gas separators and compressor surge vessels. They shall however, be provided with relief and blowdown systems in accordance with the applicable pressure vessel standards.

Gas Turbine Drivers

Gas turbines shall be fitted with acoustic enclosures generally referred to as hoods. They shall be designed to provide an H class barrier to fire and smoke egress to give an equivalent fire rating of H15.

The majority of gas turbines operating in PDO facilities are single fuel, gas driven. A few are dual fuel, such as those in power stations. The required detection systems differ slightly depending on the fuel type(s).

Fire and gas detection and protection systems for turbine hoods shall include:

Flammable gas detection on the combustion and ventilation air inlet if gas ingestion is possible.

Gas detection on the ventilation outlet and/or oil mist vapour detection (depending on type of fuel).

Heat detection. Flame detection. Fine water spray or CO2 extinguishing system.

It is possible for flammable gas concentrations up to the LEL (Lower Explosive Limit) to exist in a non-hazardous area by definition of the limits of classified areas. An example is a large flammable gas cloud in the vicinity of the combustion air intake and/or ventilation air intake. If such a possibility exists, then three flammable gas detectors shall be installed.

There is also the possibility for flammable gas to exist within the turbine hood from a release from the fuel distribution piping. Gas from such a release should be detected at the ventilation outlet. For this purpose three flammable gas detectors shall be installed to monitor the ventilation outlet airflow.

Heat detectors of the bimetallic type shall be installed over bearings. They shall be used in combination with flame detectors. A minimum of four flame detectors shall be installed, and at least one heat detector. In large turbines, e.g. Frame 5 equivalent, additional detectors may be required and in such cases the turbine manufacturers recommendations shall be followed.

If IR flame detectors are used, then to prevent false alarms due to IR detectors responding to hot turbine shafts rotating at certain speeds, the design shall ensure that the view of any rotating shaft by a detector is obscured by a casing shield.

The gas turbine manufacturer should be consulted regarding maximum ambient operating temperatures.



Electric Drivers

Heat detection of the windings in accordance with DEP 33.66.05.31, Electric Motors - Cage Induction and Synchronous Type, shall be provided as an integral part of the electric motor design.

Floating Roof Storage Tanks

The tanks shall be bunded in accordance with ERD 09-02, Spacing of Tanks and Tank Bunding Requirements.

Basic process protection from primary safety features, such as tank level measurement with level alarms, an independent high level alarm and trip and automatic ESD inlet and outlet valves shall be installed in accordance with ERD 08-11, Isolation of Process Equipment.

Further fire risk reducing measures consist of:

Fire retardant rim seals in accordance with EP 92-1820 Rim seal fire detection Local self activating one shot foam system to rim sections Facilities to allow pump out under emergency conditions Foam distribution headers to tanks with fixed external delivery

piping Fixed fire water supply, ring main and hydrants Tank top aspirating foam pourers for connection by a mobile fire

appliance at a safe distance (applicable for those locations which do not have complete fixed foam systems already installed)

Portable foam appliances for use by fire responders Fixed cooling water monitors (where fire water supply is readily

available).

Cone (Fixed) Roofed Tanks

The tanks shall be bunded in accordance with ERD 09–02, Spacing of Tanks and Tank Bunding Requirements.

Basic process protection from primary safety features, such as tank level measurement with level alarms and independent high level alarm and trip and automatic ESD inlet and outlet valves shall be installed in accordance with ERD 08-11, Isolation of Process Equipment. Further fire risk reducing measures consists of:

Fusible plug fire detection and ESD Tank contents pump out Base foam injection (top foam injection for heavy crudes) and

internal floaters Fire water ring main with hydrants Fire water ring main with monitors.

The appropriate level of protection shall be determined on a case by case basis. Based on detailed QRA on a range of fixed roof tanks in PDO a methodology has been developed to screen the economic justification of each risk reducing option (ref. Quantitative Risk Assessment for Coned Roof Tanks and Shipping Pumps, Report no. EWE 63273, 1997). Worked examples are provided in Appendix E.



The relative risk reduction of each option has been plotted as a histogram in Figure 3.2.3 (a).

Each bar of the histogram shows the distribution of damage, which covers 3 damage categories:

loss of 2 tanks causing the loss of 12 months oil production. loss of 1 tank causing 7 days of total shutdown followed by 12

months of reduced production rates at 70%. fire damage to a tank causing 4 days of total shutdown followed by

3 months of reduced production rates at 70%.

The ‘Y’ axis gives the risk index, which can be used to determine the differential risk reduction factor introduced by the various mitigation methods.

It can be seen that as the various mitigation methods are introduced not only is there a reduction in overall risk but that the damage distribution changes to give less severe consequences.

Figure 3.2.3 (a)

100

Loss of 1Tank

Loss of 2Tanks

Fire Damage

90

80

70

60

50

40

30

20

10

RIS

K IN

DE

X

Base Case

0.50.22

0.780.2

0.71

+Heat Detection +Heat Det'n & Pump-out +Heat Det'n & BaseFoam

0.5

71

66

36

0.08

0.320.6

Fire Damage

Loss of 1 Tank

Loss of 2 Tanks

33

0.05

0.35

+Heat Det'n & BaseFoam & CW Monitors

29

71%

66%

36%

33%

100%

Fire Damage

0.04

0.280.68

29%

Risk Histogram for Cone RoofedTanks in PDO Facilities

Fire Damage

0.6

0.09

+Heat Det'n/Base Foam/Portable Foam& CW Monitors

Worked examples are provided in Appendix E.

The relevance of the active risk reducing options for any particular location, in terms of the amount of capital that can be justified on break even cost-benefit grounds, can be determined by entering the relevant values into Table 3.1. From this Table, calculate the present value of the base case cost of damage for any particular installation which equates to 100 on the risk histogram (Figure 3.2.1).

The methodology described below is suitable for screening the cost benefits of fire protection to within 25% (50/50). In the event the economic justification is marginal, other factors such as loss of reputation



shall be considered. Alternatively a detailed QRA and cost benefit analysis may be performed to arrive at the appropriate level of protection.TABLE 3.1

BASE CASE COST OF DAMAGE CALCULATION PRO-FORMA System Constant based on frequency of damage x days lost:

(3.75x10-4

x 486 =)

0.18225

Cost of Deferred Oil = 2US$ per barrel 1 2

Net Oil Production per pair of tanks in BPD (e.g. for 5 tanks divide the total production by 2.5) For an installation with a single tank multiply the total production by 1.39 (to compensate for the loss of total production given the loss of a single tank)

x

= Base Case Annual Cost of Damage per Tank = $x Number of tanks covered by Protection= Base Case Annual Cost of Damage for Installation =

$

x Design Life of the Installation= Undiscounted Design Cost of Damage for Installation =

$

Discount Factor takes into account the design life of the fire protection facilities together with the average discount rate. The undiscounted value should be multiplied by the value at discount rate taken from the following table below.

Value at Discount Rate

Years 5% 8% 10%10 0.772 0.671 0.61720 0.621 0.490 0.42625 0.564 0.427 0.36230 0.512 0.376 0.313

Base Case PV of Cost of Damage for Installation $

Note 1: The value may be updated from time to time and users shall check the latest value with the Company's Corporate Economics and Production Planning Department

The risk differential values (in US$) (justified project cost of mitigation) may be found by multiplying the percentage difference in risk, taken from the histogram, by the PV base case cost of damage to give the amount which can be spent on that mitigation system.



Shipping Pumps

The installation of shipping pumps shall include basic process protection from primary safety features, such as dual seals with primary seal failure detection, vibration monitoring and high temperature detection. Automatic suction and discharge ESD isolation valves shall be installed in accordance with ERD-08-11, Isolation of Process Equipment. The design shall include a defined route for crude oil spill run off such that the ground surface slopes away from equipment that has the potential to cause escalation. The direction of the slope shall also consider fire spread and damage to protection systems and equipment.

Further fire risk reducing measures consist of: Crude oil vapour detection Heat switch fire detection Foam/water sprinkler system

The appropriate level of protection shall be determined on a case by case basis. Based on detailed QRA on a range of shipping pumps in PDO, a methodology has been developed to screen the economic justification of each risk reducing option (ref. Quantitative Risk Assessment for Coned-Roof Tanks and Shipping Pumps, Report no. EWE 63273, 1997). A worked example is provided in Appendix E.

The relative risk reduction of each option has been plotted in the following histogram – Figure 3.2.3 (b).



Figure 3.2.3 (b)

100

FireDamage

MajorDamage

90

80

70

60

50

40

30

20

10

RISK

INDE

X

Base Case +Fire Detection +Fire Det'n &Vapour Det'n

33

No Damage Fire DamageMajor Plant

Damage

33.1%

100% Risk Histogram for Shipping Pump Sets in PDO Facilities

0.5

+Fire Det'n &Sprinklers

+Fire Det'n &Vapour Det'n &

Sprinklers

Day Manning+Fire Det'n

Day Manning+Fire Det'n &

Vapour Det'n

Day Manning+Fire Det'n &

Vapour Det'n &Sprinklers

Day Manning+Fire Det'n &Sprinklers

MinorDamage

Fire Damage

0.03

0.00

2

0.28 0.690.5

Min

or D

amag

e

0.01

2

0.81

7 0.12

70.

052

7.2%

FireDamage

0.00

50.28

0.524

Min

or D

amag

e27.3%27

0.02

0.451

Min

or D

amag

e

0.00

4

0.816

0.09

60.

083

5.6%5.6

FireDamage

0.02

1

0.486

23.4%

0.2

23

0.00

4

0.86

0.09

70.

04

4.7%4.7

0.29

No

Dam

age

0.01

7

0.486

21.5%

0.320.29

No

Dam

age

21

Min

orD

amag

e

Fire

Dam

age

0.00

3

0.86

0.07

40.

064

4.3%4.3

Min

or D

amag

e



Each bar of the above histogram shows the distribution of damage that covers 4 damage categories and includes the no damage category:

Major plant damage causing the loss of 2 months total oil production followed by 3 months at 50% production.

Fire damage to a pump causing the loss of 5 days total oil production followed by 3 months at 83% production.

Minor damage to a pump causing the loss of 3 days production followed by 2 months of reduced production rates at 83%.

The ‘Y’ axis gives the risk index that can be used to determine the differential risk reduction factor introduced by the various mitigation methods.

It can be seen that as the various mitigation methods are introduced not only is there a significant reduction in overall risk but that the damage distribution changes to give less severe consequences. The no damage category does exist for the base case but is not shown for clarity since it represents a part of the damage distribution common to all the above conditions. The sections of the bars above shown as no damage are purely attributable to the introduction of mitigation. It can be seen that vapour detection and manning give a significant benefit by increasing the no damage allocation. This is because both can provide leak detection prior to ignition that results in spill damage, which is considered insignificant in comparison to fire damage.

The relevance of the active risk reducing options for any particular location, in terms of the amount of capital which can be justified on break even cost benefit grounds, can be determined by entering the relevant values in the Table 3.2. This can be used to calculate the present value of the base case cost of damage per pump set for any particular installation which equates to 100 on the previous risk histogram (Figure 3.2.3 (b)).

The methodology described below is suitable for screening the cost benefits of fire protection to within 25% (50/50). In the event the economic justification is marginal, other factors such as loss of reputation shall be considered. Alternatively a detailed QRA and cost benefit analysis may be performed to arrive at the appropriate level of protection.

A worked example is given in Appendix E.



TABLE 3.2

BASE CASE COST OF DAMAGE CALCULATION PRO-FORMA System Constant based on frequency of damage x days lost for 3 pumps:

(3.18x10-4

x 130 x 3 = )

0.12402

Pump Type for centrifugal/axial or screw pumps use x 1for reciprocating pumps use x 10

x

Number of Pumps in Set for 2 pumps use x 0.6for 3 pumps use x 1.0for 4 pumps use x 1.46for 5 pumps use x 2.0

x


Net Oil Production for Pump Set in BPD X= Base Case Annual Cost of Damage per Pump Set = $x Design Life of the Pump Set= Undiscounted Design Cost of Damage for Pump Set =

$


Value at Discount RateYears 5% 8% 10%10 0.772 0.671 0.61720 0.621 0.490 0.42625 0.564 0.427 0.36230 0.512 0.376 0.313

Base Case PV of Cost of Damage for Installation $

Note 1: The value may be updated from time to time and users shall check the latest value with the Company's Corporate Economics and Production Planning Department.

The risk differential values (in US$) (justified project cost of mitigation) may be found by multiplying the percentage difference in risk, taken from the histogram, by the PV base case cost of damage to give the amount which can be spent on that mitigation system.

3.2.4 Gas Processing Facilities

Fuel Gas Treatment Skids

Consideration shall be given to the installation of fixed gas detection, however the effectiveness of such units in generally open type facilities should be included in the evaluation. In the event that fixed detection is not effective, a programme for regular gas testing by the operator is required.

Gas Fired Heaters

Fire and gas detection for gas fired heaters shall be determined on a case by case basis. Consideration shall be given to the installation of gas



detection, however the effectiveness of such units in generally open type facilities should be included in the evaluation.

Compression Facilities

Generally, no detection is required for gas separators and compressor surge vessels. They shall however, be provided with relief and blowdown systems in accordance with the applicable pressure vessel standards.

Centrifugal Compressors

Centrifugal compressors shall be equipped with heat detectors above each bearing with a seal or gland. They are intended to detect both gas fires and lube oil fires.

Reciprocating Compressors

Fire and gas detection for reciprocating compressors shall be determined on a case by case basis. As a minimum they shall be equipped with heat detectors above each bearing with a seal or gland as per centrifugal compressors.

LNG/LPG Vessels

Fire and gas detection for LNG/LPG vessels shall be in accordance with DEP 80.47.10.30 Gen. Section 5.5.1, Pressurised Storage Vessels.

LPG vessels shall be provided with a sloping drain such that the slope is not directed to protective systems or potential escalation areas.

Use of fixed cooling water spray systems is justified where an existing fire water system is in place. Where blocking is a problem for water nozzles, provision of passive fire protection may be considered.

LPG Loading Facilities

Fire and gas detection/protection for LPG loading facilities shall be in accordance with DEP 80.47.10.30 Gen. Section 5.7.2, Road Car Loading Facilities.

3.2.5 Booster Stations

The overall strategy for pipeline booster stations is level 2. The fire protection specifications of the individual equipment in such facilities are similar to equipment in production and gathering stations.



3.3 Utility Facilities

3.3.1 Power Stations

Turbine Driven Generation Sets

The overall strategy is level 2 – fixed fire systems for the turbine driver only (see 3.2.3, Gas Turbine Drivers).

Generators shall be provided with heat detection and UV flame detection over the main areas.

Auxiliary Diesel Generator

The overall strategy is level 2 – fixed fire systems.

Auxiliary diesel generators shall be provided with heat detection and an automatic extinguishing system, typically a self-contained dry powder system, or a fine water spray system. Installation of such systems generally require that the engine is enclosed and not subject to any local air movement, which should be the case when the engine has tripped and the mechanically driven cooling fan has stopped.

3.3.2 Control and Auxiliary Rooms

Conventional smoke detection shall be installed. Generally these shall be ceiling mounted. Location of detectors below the floor or above the ceiling should be avoided. Additionally, detectors should be provided where cables are located in voids.

3.3.3 Electrical Substations and Switchgear Rooms

Conventional smoke detection using a combination of optical and ionisation detectors shall be installed. At least one of each type of detector shall be used in each location. The detectors should be connected into two zones such that any incident is likely to activate at least one detector from each zone (to avoid common mode failures). Voting logic shall be determined by IPF classification and implementation methodology.

Note: For critical control and switchgear rooms, containing sophisticated computerised systems, consideration should be given to the installation of an incipient smoke detection system which would only be used for very early alarm purposes.

3.4 Office Buildings, Residential And Industrial Areas

3.4.1 General

The overall strategy for buildings in which people are generally present is level 1 with some level 2 exceptions as further specified below. The primary protection for people is to provide fire/smoke detection, alarm and adequate escape routes. Smoke detection and Manual Alarm Call (MAC) points connected to a general audible alarm shall be installed in accordance with ERD 17-02 Building Services Construction Specifications, Section (D), Fire Detection and Alarm Installation.



No Smoking signs

No smoking signs shall be clearly displayed in all areas where smoking is prohibited.

Visual alarms

The main visual alarm interface shall be the fire detection panel. This shall be located at the main entrance to the building. The panel shall clearly highlight which detection circuit has been activated and the area of the building affected.

Audible Alarm

In residential areas the audible alarm shall be in the form of a horn or bell.

Escape Routes

All escape routes and exit doorways shall be provided with emergency lighting where required. They shall be marked with luminous or illuminated signs

Fire Wardens

Fire Wardens signs shall be clearly displayed in all critical areas

Fire Extinguishers

A suitable number of hand-held extinguishers shall be provided at strategic locations. If a fire water system is installed then hose reels shall also be provided at strategic locations.

Manual Alarm Call-points

Manual Alarm Call (MAC) points shall be installed at the main exits, at all emergency exits and along corridors at intervals not exceeding 100m. The design of MAC’s shall conform to BS 5839 Part 2, and may either be of the hammer/break glass or push/break glass type.

3.4.2 Plans and Procedures

Plans and procedures shall be put in place for:

Building evacuation and muster points Fire fighting Maintenance and testing of fire protection equipment

Guidance in the preparation of such plans can be found in GU 230 FERM Facility Plan Guideline.

3.4.3 Office Buildings

All flammable liquids, including photocopier toners, cleaning solvents and draughtsman’s sprays shall be stored in metal cabinets away from sources of ignition such as heat or naked flame.

For locations containing critical computer equipment, consideration should also be given to the installation of an incipient smoke detection system which would only be used for very early alarm purposes.



Materials storage areas shall be provided with fire detection applicable to the type of material being stored. In areas where the stored materials give off flammable vapours, e.g. seismic tape stores, the electrical installation shall be suitable for zone 2.

Where the contents of a building are particularly valuable or critical, such as some archives and data stores, a total flood system may be justified in order to minimise the potential loss. Cost Benefit Analysis should be applied in order to provide the justification. The type of extinguishant used for total flood systems shall provide minimum environmental impact and health risk, and shall be approved by the Custodian of this Specification (CSM).

3.4.4 Residential Areas

Kitchens

In all kitchens serving a residential camp CO2 or foam extinguishers and a fire blanket shall be provided. Fire blankets shall be woven glass fibre tested to BS 476 Parts 4 and 7.

Heat detection shall be installed in the kitchen hood. Activation of the detector shall:

shutdown kitchen hood ventilation fan shut off gas supply to the kitchen initiate audible alarm shutdown air conditioning system.

On line gas bottles for use in kitchens shall be located outside. If the bottles are closer than 5 metres from combustible materials a block work separation wall shall be constructed. Any enclosure for gas bottles shall be freely ventilated.

3.4.5 Industrial Areas

Laboratories

Fire protection in laboratories shall be designed in accordance with DEP 34.17.10.31. On line gas bottles for use in laboratories shall be located outside. If the bottles are closer than 5 metres from combustible materials a block work separation wall shall be constructed. Any enclosure for gas bottles shall be freely ventilated.

Workshops

In workshops free of dust and vapours, smoke detection shall be provided. In workshops areas where smoke detectors may become quickly contaminated due to dust and vapours, heat detection shall be provided instead of smoke detection. The location of such heat detectors is critical as a fire can become well established before activating a heat detector.



3.5 Airstrips

3.5.1 Aircraft rescue and fire fighting

The overall strategy is level 4. Fire fighting facilities at permanent airstrips associated with locations in the interior shall meet the requirements of the applicable ICAO Cat 4/5 specifications within the Airport Services Manual, including publications ICAO-9137P1, Rescue and Fire Fighting, and ICAO-9137P7, Airport Emergency Planning.

3.5.2 Mobile Equipment

The principle requirement is rapid response such that in the event of a crash on landing or take-off a fire engine could reach the plane before ignition of any spilt aviation fuel, hence the need for four-wheel drive.

For mobile fire fighting equipment reference should be made to DEP 80.47.10.32, General and for fire fighting vehicles, DEP 80.47.10.33.

3.5.3 Air strip buildings

The general specifications as defined in Section 3.4.1 above shall be applied.



4.0 Detection Specifications

4.1 Detection Systems

The design of fire and gas detection systems for green-field sites shall be in accordance with DEP 32.80.10.10, General, and if a PLC based system is used, DEP 32.80.10.30, General. For brown-field sites, the existing system design philosophy should be followed. Determination of revealed and unrevealed failure robustness shall be in accordance with DEP 32.80.10.10, General.

The power supply to the system shall be provided with a battery back up giving 8 hours duration, 7.75 hours at normal load and 0.25 hours at alarm load.

4.2 Gas Detection

4.2.1 Flammable Gas Detection Philosophy

It is important that the detectors used are suitable for the type of gas that they are intended to detect and that the test gas used is as close as possible to the process gas.

Point type gas detectors shall be used. The use of open path gas detectors may be considered only when used in conjunction with point type detectors.

Flammable gas detection shall initiate alarms at alert and danger levels. Executive actions shall only be initiated from danger level detection. The location and number of detectors required is a function of the particular equipment design and layout, however they shall be located over obvious potential leak points e.g. seals.

It is recommended that the following settings be adopted as a sensible balance between sensitivity and reliability in terms of avoiding unnecessary activation.

TABLE 4.2

Location Alert Level Danger LevelGeneral process areas 20%LEL 50%LELAreas where greater sensitivity is desirable and any trip action does not cause a major plant shutdown

10%LEL 20%LEL



4.3 Fire Detection

4.3.1 Optical Flame Detection

Infra-Red (IR) flame detectors are the preferred type for flame detection as they are not susceptible to spurious trips, they can detect flames from smoky fires and they can tolerate considerable dirt on the lens. They shall be solar blind and flicker frequency sensitive for hydrocarbon fires. Detectors should generally be located in elevated positions and aligned downwards to gain maximum benefit from the fixed angle of sensitivity.

The use of Ultra Violet detectors in areas where arc welding, flash photography and NDT X-Ray testing shall be carefully considered. Detectors should be located in elevated positions looking downwards. Consideration should be given to the possibility of smoke accumulation preventing the detector from seeing a flame. UV detectors shall provide an alarm signal to alert operators when the window is dirty.

Flame detection shall initiate alarms and executive actions.

4.3.2 Bimetallic Heat Detection

Bimetallic heat detectors shall be of the fixed type. They shall have a set point approximately 25° C higher than the maximum ambient temperature (to be taken as 55° C). For outside locations the ambient conditions are defined in ERD 10-04. For inside locations the maximum ambient temperatures must be determined.

4.3.3 Fusible Plug Heat Detection

Fusible plugs shall be selected to melt at approximately 25° C higher than the maximum ambient temperature (to be taken as 55° C). For outside locations the ambient conditions are defined in ERD 10-04. For inside locations the maximum ambient temperatures must be determined. The configuration of fusible plug systems is given in ERD 30-03.

Low-pressure initiator monitoring of air pressure in the system shall be used for fire detection.

4.3.4 Fusible Link Heat Detection

Fusible links shall be selected to melt at approximately 25° C higher than the maximum ambient temperature (to be taken as 55° C. For outside locations, the ambient conditions are defined in ERD 10-04. For inside locations, the maximum ambient temperatures must be determined. They should generally only be used when they form part of a vendor detection/protection package.



4.3.5 FQB Heat Detection

Frangible quartzoid bulbs shall be selected to break at approximately 25° C higher than the maximum ambient temperature (to be taken as 55° C). For outside locations the ambient conditions are defined in ERD 10-04. For inside locations the maximum ambient temperatures must be determined. They should generally only be used when they form part of a vendor detection/protection package.

This type of heat detection is preferred for congested process plant areas unless the equipment is subject to periodic removal.

4.3.6 Smoke Detection

Smoke Detection

Smoke detectors shall be of the optical type or ionisation type. Where smoke detection is provided, at least one of each type shall be installed at each location. The optimum locations for conventional smoke detectors will be a function of the preferential air flow patterns.

Activation of a single smoke detector shall initiate alarms and executive actions.

Note: According to BS 5839 Part 1 false alarms from smoke detectors may be caused by fumes, dusts or condensation. Some types of ionisation chamber type smoke detectors are highly sensitive to high air speeds and may give false alarms.

Ionisation type detectors shall be provided with a warning that label highlights them as a radioactive source.

Incipient Smoke Detection

The use of incipient smoke detection systems (also called VESDA - Very Early Smoke Detection Alarm) systems) shall be considered for facilities containing critical control monitoring systems such as control rooms, equipment panels and substations.

This type of system is capable of detecting fire at the incipient stage up to 4 hours before flame breaks out.

The extremely high sensitivity of these systems may tend to cause alarms occasionally under transient conditions. They should only therefore be used to initiate alarms, not executive actions.

Note: None of these devices are suitable for fume contaminated areas typically including vehicle exhausts or cigarette smoke, and clearly have limited applicability in inherently dirty or dusty environments.



4.4 Audible, Visual and Manual Alarm Call Points

4.4.1 Hydrocarbon Handling and Utility Facilities

Audible Alarms

Audible alarms shall be installed on the outside of the control building as a minimum. Different alarm sounds shall be used for fire, combustible gas, toxic gas and all clear. These shall be in accordance with DEP.32.30.20.11, General. Additional audible alarms shall be located on top of noisy machinery e.g. gas turbines.

Visual alarms

The main visual alarm interface shall be the mimic. This shall either be a dedicated display on the control system or a graphic mimic panel. The mimic layout shall be based on the station fire and gas detector layout drawings. It shall clearly highlight which detection circuit has been activated and the area of the plant affected. Design of the mimic shall be in accordance with DEP.32.30.20.11, General.

When H2S detection is provided, visual beacons shall be installed in accordance with ERD 08-04.

Manual Alarm Call-points

Manual Alarm Call (MAC) points shall conform to BS 5839 Part 2, and may be either of the hammer/break glass or push/break glass type. They shall be installed at all plant escape gates, at the plant main gate and at the control building entrance. If escape routes are clearly defined (i.e. signs are installed) then they shall be located along them at intervals not exceeding 100m. They are not required for off plot facilities such as remote manifolds.



5.0 Fire Protection Systems

5.1 Fire Water Systems

A fire water network consists of a water supply (usually a dedicated tank), pumps and a piping distribution network. The network outlets can be hydrants (for use, generally with hand-held or mobile equipment), fixed systems such as base foam injection, deluge systems etc. or fixed monitors.

It is however acceptable to take the firewater supply from a process system (eg. water injection system) provided that pressure and flow can be maintained under emergency conditions.

Fire water systems are required for facilities where FERM strategies 3 and 4 have been justified.

5.1.1 Fire Water Network – General

Where the FES dictates the need for a fire water system (strategy 3 and 4) the design shall comply with DEP 80.47.10.31.

The fire water network shall be designed to supply the calculated water demand at the required discharge points and pressure (reference shall be made to preplanning documentation for required flow rates).

The pumps should discharge into a ring main with hydrants, fixed monitors and feeds to fixed foam systems and sprinkler systems.

The fire water distribution piping shall be a ringmain, with adequate loops and block valves to ensure that a single line break can be isolated safely with minimum loss of fire protection. Single branch lines shall be avoided.

The piping material may be steel for above or below ground and GRE (in accordance with ERD 38-12) where mechanical damage is unlikely. Steel pipe shall be cement lined in accordance with DEP 30.48.30.31, General. When above ground, the pipe shall be protected by physical barriers where necessary to reduce the possibility of impact by vehicles.

All valves in the system shall be clearly identified with their function and normal status. System pipework shall be routed such that wherever possible it is not exposed to excessive radiation from a fire for which it may be required. In particular, the following guidelines shall be applied:

Fire water pipework shall not pass through tank bund areas. Fire water pipework shall not pass through areas where product

spills can accumulate underneath them. Fire water pipework shall be at least 15m from process facilities.

System isolation valves shall be located such that radiation (based on FRED calculations) from fires for which they are intended will be a maximum of 5 kW/m2 under any anticipated design conditions. If the system is such that its user is likely to remain in the area for extended periods (greater than 10 minutes), then screening shall be provided to ensure that radiation levels do not exceed 1.5 kW/m2.



5.1.2 Fire Water Storage Tank

The capacity of the water storage tank shall be in accordance with the worst case design demand (reference shall be made to pre-planning documents to assist in determination of total water demands). A minimum of 6 hours supply shall be provided unless it can be clearly shown that incident duration will be less than this (e.g. by shutdown and isolation). It may be necessary to consider the installation of two tanks depending on size and the location characteristics.

The fire water tank internal lining shall be in accordance with ERD 48-01 to obviate the generation of corrosion products which could affect the performance of downstream systems.

A system would typically include a water storage tank (in accordance with NFPA 22) for those areas without a suitable natural source of water. The tank may be filled with formation water provided the quality is compatible with available foam concentrates.

Since the majority of the tank(s) fill is likely to stand for considerable periods of time consideration shall be given to batch dosing foam compatible corrosion inhibitor and bactericide.

Where required due to the type of pumps being used, tanks shall be elevated to provide positive suction when the operating pressure is low.

5.1.3 Fire Water Pumps

Pumps and drivers shall comply with DEP 31.29.02.11, General, DEP 31.29.02.30, General, and NFPA 20, Installation of Centrifugal Fire Pumps.

Generally two 100% fire water pumps, one electric and one diesel driven, shall be installed to ensure a reliable supply under all circumstances. The electric driven pump would normally be selected to start first, either from a confirmed fire signal as a precursor to fire water demand or due to a fall in pressure in the ringmain. The diesel driven pump would start automatically on low ring main pressure after a pre-set time or on failure of the electric pump.

A jockey pump shall be installed to maintain pressure in the system (typically 3 barg).

Fire water pumps shall be started weekly and performance tested annually. The annual performance tests shall incorporate flow tests for the ringmain itself. Flow and pressure tests shall be performed on the fire water system to ensure that water demand for the identified scenarios can be achieved.

Pumps shall be selected and installed in accordance with DEP 31.29.02.11, General, DEP 31.29.02.30, General and NFPA 20.

5.1.4 Hydrants

Hydrants in process areas shall generally have 4 x 65mm instantaneous coupling outlets in accordance with BS 336. Hydrants at offices, residential and industrial areas shall generally have 2 x 65mm outlets.



Fire Hoses

All hoses for fire fighting purposes shall conform to the requirements of DEP 80.47.10.32, General, Section 3.2.

5.1.5 Monitors

Fixed, manually operated water monitors shall be provided for strategy 3 facilities for specific cooling requirements, i.e. storage tanks and congested areas as justified by risk analysis.

Self Oscillating Type Monitors

Self oscillating type monitors should be considered where identified as advantageous. Monitors shall be located outside storage tank bund walls. They shall not be located inside or on top of the bund.

Fixed Monitors

Fixed monitors shall be chosen to provide the stream range required to cool the equipment for which they are provided at the design operating pressure. The flow rate shall not be less than 2000 lpm at the design operating pressure.

Access during a fire should be taken into account where locating fixed monitors. The effects on firefighters from radiant heat during a storage tank fire also need to be considered. Monitors shall be located such that radiation (based on FRED calculations) from fires for which they are intended will be a maximum of 5 kW/m2 under any anticipated design conditions. If the system is such that its user is likely to remain in the area for extended periods (greater than 10 minutes), then screening shall be provided to ensure that radiation levels do not exceed 1.5 kW/m2.

DEP 80.47.10.32, General, gives information regarding the requirements for fixed monitors, and DEP 80.47.10.30, General, provides information on water flow rates. The design of portable water monitors shall be in accordance with DEP 80.47.10.32, General.

5.2 Water Application Systems

Water application systems can be used to control fire spread or to provide cooling of radiation exposed facilities and, in certain circumstances, can extinguish fires.

Water application systems will not generally extinguish fires caused by hydrocarbon flammable liquids with flash points below ambient temperature or flammable liquids heated above their flash points. Foam systems are required for this application.

Water application systems consist of a valve in a take-off from the fire water network, distribution pipework and discharge nozzles.



There are two basic types of discharge nozzle:

(i) Sprinkler nozzles - where each nozzle has a frangible bulb or fusible link preventing water flow through the nozzle. At a preset temperature the bulb or link breaks and releases water. Thus, only the nozzles subjected to heat discharge water. Typical applications of sprinkler systems include offices and hazardous material warehouses. They should not normally be used in computer rooms or electrical equipment rooms.

(ii) Waterspray (deluge) nozzles - where all nozzles are open and, on opening of the valve, will all discharge simultaneously. Deluge systems can be automatic or manually operated according to specific hazard requirements.

5.2.1 Sprinkler Systems

Reference shall be made to DEP 80.47.10.31, Section 2.3.

Sprinkler systems shall be designed in accordance with NFPA 13 or BS 5306, Part 2.

Sprinkler system hydraulic calculations shall be carried out using approved software rather than by manual calculations.

Sprinkler systems shall normally be of the wet pipe type. Where the protected area contains critical equipment and water damage from sprinkler nozzle leakage would have major consequences, consideration may be given to the installation of a pre action system, typically consisting of dry pipe, requiring confirmation of fire from another source before the valve is opened.

All system sprinkler valves and nozzles shall be approved by the Loss Prevention Council (LPC), Underwriters Laboratories (UL) or Factory Mutual (FM).

Sprinkler system inspection and testing shall be in accordance with NFPA 25 or BS 5306, Part 2.

5.2.2 Waterspray (Deluge) Systems

Waterspray systems shall be designed in accordance with DEP 80.47.10.31, Section 2.2 and NFPA 15.

Automatic deluge valves and nozzles shall be approved by Loss Prevention Council (LPC), Underwriters Laboratories (UL) or Factory Mutual (FM).

Deluge system valves shall be located such that radiant heat levels from the incident for which they are provided shall be located such that radiation (based on FRED calculations) from fires for which they are

intended will be a maximum of 5 kW/m2 under any anticipated design

conditions. If the system is such that its user is likely to remain in the area for extended periods (greater than 10 minutes) then screening shall be provided to ensure that radiation levels do not exceed 1.5 kW/m2.



Automatic deluge valves shall be actuated by the relevant detection system but shall also include a manual operation capability. The preferred method of operation of automatic deluge valves is by fusible plug detectors. Water deluge valves in pipe work shall be locked in the open position. Special consideration shall be given to the locking of ball valves such that they cannot be closed with the lock in place. Ideally, the valves should be purchased with a lock as part of the design.

Testing and inspection of deluge systems shall be in accordance with NFPA 25. Regular maintenance of the system shall be performed, and in particular the deluge nozzles shall be checked for blockage. Regular flushing of the nozzles shall be performed.

5.3 Foam Systems

5.3.1 General

Foam systems consist of 3 basic parts:

(i) Foam concentrate - the liquid used to foam(ii) Foam concentrate proportioning system - where the foam concentrate is

mixed, at a specific proportion, with water to make foam solution.(iii) Foam maker (foam generator, foam application device) where air is

mixed with foam solution to make foam.

Foam makers can be further subdivided into aspirating types which use a venturi nozzle system to draw air into the foam solution and non-aspirating devices which rely on impinging jets of foam solution or turbulence as the foam solution leaves the nozzle to generate bubbles of foam.

In any system, it is important to ensure that the right combination of foam concentrate, proportioning system and foam generating devices are selected for the particular application. The following sections deal with specific requirements for these components for PDO facilities.

Reference shall be made to the following standards for relevant aspects of foam system design and foam concentrate specification:

DEP 80.47.10.31 - Gen., June 1992, Section 2.4 DEP 80.47.10.10 - Gen., March 1991, Section 2.1 DEP 80.47.10.33 - Gen., Fire Fighting Vehicles and Fire Stations,

June1993 NFPA 11 - Standard for Low Expansion Systems NFPA 16 - Deluge Foam - Water Sprinkler and Foam Water Spray

Systems, 1995 ISO 7203 - 1 Fire Extinguishing Media, Foam Concentrates, 1995 UL 162, Seventh Edition - Foam Equipment and Liquid

Concentrates, 1994

For airport applications, reference shall be made to ICAO, CAP 168 - Licensing of Aerodromes, 1990.

5.3.2 Foam ConcentrateWherever possible, the number of different foam concentrates on site shall be limited to one. If this is not possible, measures shall be in place to minimise the possibility of mixing the different types.



All foam concentrates used shall be 3% grade (i.e. to be used at 3% concentration in proportioning systems).

The foam concentrate for hydrocarbon flammable liquids (e.g. crude or condensate) shall be either fluoroprotein, film-forming fluoroprotein or multipurpose (alcohol resistant) fluoroprotein or synthetic based type and shall conform to the requirements of Underwriters Laboratories UL 162 7th Edition test requirements, or ISO 7203-1 Class IIA or higher.

The foam concentrate for water soluble flammable liquids (e.g. methanol) shall be a multipurpose type and shall conform to the requirements of Underwriters Laboratories UL 162 7th Edition test requirements or ISO 7203-1 Class IIA or higher.

The foam concentrate for airstrip use shall be AFFF (Aqueous Film Forming Foam), FFFP (Film Forming Fluoroprotein) or a fluoroprotein type conforming to the requirements for level B type foams of CAP 168 (multipurpose types of the same generic type are permissible).

Foam concentrates whether in systems, drums or vehicles shall be stored such that they are not exposed to direct sunlight.

Calculations shall be performed in order to establish the minimum quantity of foam required for each application. In addition, and in accordance with NFPA, 100% of the calculated quantity shall be available within 24 hours.

For foam concentrate at airstrips, certification shall be available on site demonstrating full conformity with CAP 168. This shall include results of the extinguishing test on the original foam concentrate batch as well as the following physical properties with measurement tolerances:

Specific gravity @ 20C pH @ 20C Sediment Viscosity @ 20C

For foam concentrate for use at facilities other than airstrips, manufacturers type certification shall be available on site demonstrating full conformity with either UL 162 or ISO 7203-1, Class IIA or higher.

This shall also include information on the following physical properties with measured tolerances:

Specific gravity @ 20C pH @ 20C Sediment

Foam Concentrate Testing

Representative samples of all foam concentrates used at PDO facilities shall be subjected to the following tests to determine whether or not they continue to conform to original manufacturers specifications. The test can either be carried out by the original manufacturer or on-site to written procedures.

(i) On an annual basis, the following physical properties shall be



measured:

Specific gravity @ 20C pH @ 20C Viscosity @ 20C (for foam concentrate used at airstrips) Sediment

(ii) Every 10 years, the foam concentrate used at airstrips shall be subjected to a fire test in accordance with CAP 168 to ensure continuing conformity with level B type fire fighting performance.

5.3.3 Foam Proportioning SystemsThe foam proportioner is the device that is used to inject foam concentrate into the water line to make foam solution. It is vital that the proportioner is such that it ensures that the foam solution has the correct amount of foam concentrate in it (nominally 3%) under all system operating conditions and flow requirements, including potential blockage of one or more outlets.

Various types of proportioner are available as described in NFPA 11. This section defines the type that shall be used for different applications at PDO facilities.

General

All foam proportioning systems shall be capable of providing acceptable concentrate proportioning (3-3.6%) under all operating conditions of the equipment, including blockage of some outlets.

Foam concentrate tanks shall be high-density polyethylene, GRP or stainless steel 316L construction, approved for use by the concentrate manufacturer.

Internal tank linings shall not be used in foam concentrate tanks.

Proportioning Systems for Fixed Foam Systems

Foam application systems as described in 4.6.4 can be either fixed or semi-fixed. In the case of fixed systems, the proportioner and foam concentrate tank are permanently connected to the fire water ring main so that no additional connection of foam concentrate supply is required for system operation.

FERM strategy 3 sites and strategy 4 sites shall have fully fixed systems. Semi-fixed systems may be added at sites with a professional fire response nearby. In such a case the fire responders shall be trained and regularly practice the use of such equipment (see Proportioning Systems for Semi-Fixed Foam Systems below).

All proportioning stations shall be provided with a clear indication of the facilities to which they relate and clear operating instructions including identification of valves. Minimum and maximum operating pressures shall also be clearly identified.

All proportioning stations shall be located in safe locations (i.e. areas not having hazardous area classification).



All proportioning stations shall be located such that radiation (based on FRED calculations) from fires for which they are intended will be a maximum of 5 kW/m2 under any anticipated design conditions. If the system is such that its user is likely to remain in the area for extended periods (greater than 10 minutes), then screening shall be provided to ensure that radiation levels do not exceed 1.5 kW/m2.

Standard inductors (line proportioners, eductors) shall not be used.

Fixed proportioning systems shall be of the balanced pressure type (See NFPA 11). The preferred type is one having a foam concentrate pump although diaphragm tank (bag tank, bladder tank) types are acceptable where the quantity of foam concentrate in them does not exceed 1500 litres.

For pumped balanced pressure proportioning systems, the pump can be water, electric or diesel driven. In all cases the pump shall be of the positive displacement type (i.e. not centrifugal).

All proportioning stations shall be provided with isolation valves and pressure gauges at their inlet and outlet. In the case of pumped balanced pressure proportioning systems, pressure gauges will also be provided in the foam concentrate line downstream of the foam pump prior to the proportioner. Gauges shall be provided to demonstrate that foam concentrate pressure and water pressure are balanced at the point of concentrate injection.

The flow range of the proportioner and operating pressure range shall be clearly marked on the proportioner.

Pumped balanced pressure proportioning systems shall be provided with the facility to test the foam concentrate and circulate foam concentrate back to the concentrate tank without discharging concentrate into the foam solution discharge line. Valves in the system specifically provided to allow this function shall be provided with a lock so that they can be locked during normal status.

Pumped balanced pressure proportioners shall have manual over ride capability to be used in the event of failure of the automatic balancing system.

All foam concentrate tanks shall be provided with a sight glass with isolation valves. In the case of diaphragm tanks the isolation valves will be provided with locks.

In areas where specialist fire vehicles are available (strategy 4 in FERM), a pumping in connection shall be provided downstream of the proportioning skid to allow back up of a fixed proportioning system by use of the proportioning system on the vehicle.

In the case that hand held equipment outlets are served by the proportioning station as well as fixed systems, the outlets shall be such that pressure is limited to a maximum of 7 barg.



Proportioning Systems for Semi-Fixed Foam Systems

Semi-fixed foam application systems are those that require connection of a mobile proportioning system (usually on a fire truck). They are, therefore, only applicable where strategy 4 of FERM is adopted.

The foam system shall conform to the requirements of DEP 80.47.10.33, General.

Proportioning systems on specialist vehicles shall be pumped balanced pressure type. The system shall be such that each vehicle outlet can provide foam solution or water as required (i.e. the system must not be such that when foam solution is being produced at some outlets, it is not possible to have water only at others).

The flow rate capability of the proportioning system shall take due account of other items, such as foam monitors or hand lines, which may be fed from it.

The proportioning system shall have the manual over ride, drain and return to tank facilities as described for the pumped proportioning systems for fixed systems in the previous section.

Note: The above comments should not be regarded as a detailed specification for foam systems for fire trucks. They cover only the necessary requirements to serve semi-fixed systems at PDO facilities.

Proportioners for Hand Held Foam Nozzles

Standard line proportioners (eductors, inductors) shall be used for providing foam solution to hand held nozzles which are not fed from a specialist fire vehicle (see Proportioning Systems for Semi-Fixed Foam Systems) or a fixed proportioning system. Proportioners for hand held nozzles shall conform to the following requirements:

The proportioner setting shall be fixed at 3%. The proportioner shall be provided with a translucent pick up tube. The line proportioner shall incorporate a non-return valve to

prevent back flow of water into the foam concentrate supply.

Proportioners for One Shot Foam Systems for Floating Roof Tank Rimseal Fires

Proportioners for one-shot foam systems for floating roof tank rimseal fires are considered to be an integral part of a package unit (see previous section).

Testing of Proportioning Equipment

On an annual basis all proportioning systems and equipment shall be tested under credible operational flow conditions to check that the percentage of foam concentrate being proportioned is within the range 3-3.6%.

At 6 monthly intervals, foam concentrate tanks shall be inspected for signs of sediment.



5.3.4 Foam Application Systems/Equipment

Base Injection Systems

Reference should be made to DEP 80.47.10.31, General, Paragraph 2.4.1.1.

Base injection (sub-surface) systems are used to protect cone roof (fixed roof) atmospheric storage tanks that do not have an internal floating cover. They are designed to inject foam at the base of a tank above any water and allow the foam to float to the fuel surface. Base injection foam systems are not suitable for water-soluble fuels such as methanol.

A variation of this system, known as semi-subsurface, includes a flexible tube that is released into the product on system actuation. Foam flows up the tube so that it does not actually come into contact with the product. Semi-subsurface can be used for water soluble fuels or for crudes with a very high water content where the water base in a tank can be very high and base injection is not practical.

Base injection systems shall be designed in accordance with NFPA 11 in terms of application rate, running times, foam discharge velocities and number of foam application points. Base foam injection is limited for use with hydrocarbons that have a viscosity less than 440 centistokes at the minimum storage temperature. Above this, top entry for the foam should be used.

Base injection systems shall be used in preference to semi-subsurface systems wherever possible. At manned facilities, actuation of a base foam injection shall be manual. At unattended facilities where manual actuation would result in a delay of more than 30 minutes following confirmation of a fire alarm, actuation of base foam systems shall be automatic.

Each tank nozzle associated with a base injection system shall be provided with a normally locked open shut off valve and a non-return valve.

Bursting discs shall be provided upstream of the non return valve in the foam discharge line to act as a positive seal preventing product entering the foam line under normal operations. The bursting discs shall be of the differential pressure type, rated and located such that where there is more than one disc in a system, the bursting of one disc will not relieve pressure throughout the system and prevent the bursting of all other discs.

Valved test connections shall be provided in a base injection system on each system outlet. These shall be of the same diameter as the system foam outlets in order to be representative of the actual system. The valve of the test connection outlet shall be normally locked closed. Normally locked open valves shall be provided as necessary in the foam discharge outlets. These valves shall be closed during testing to prevent bursting discs being subjected to high pressure.

Foam generators for the base injection system shall be of the type that can generate foam of the required expansion and drainage time properties (see NFPA 11) against backpressure caused by product head and downstream frictional losses. The preferred type is one that can operate against at least 40% backpressure. The generators shall be provided with



pressure gauges showing upstream and downstream pressures so that operating conditions can be checked during testing. The generators shall incorporate a non-return valve in the air inlet to prevent backflow of product through the inlet after system shutdown.

All foam generators shall be located outside the bund wall.

In the case of semi-fixed systems requiring connection to a firefighting vehicle, any valves or controls needed for system actuation shall be outside the bund and such that radiation levels during credible scenarios meet the radiation level limits described for fixed proportioning systems as detailed above.

In semi-fixed systems, the foam solution inlets shall be clearly marked with their purpose, the tank numbers to which they relate, the minimum operating pressure and flow rate.

Each foam generator shall be clearly labelled with its minimum operating pressure and the flow rate at this pressure.

The foam outlet inside the tank shall be such that it does not become easily clogged by sediment. In crude tanks this means that the end of the outlet pipe should be cut at an angle so that any sediment in the crude does not accumulate in the pipe.

All foam systems shall be discharge tested on an annual basis. The tests shall include proportioning accuracy (see Testing of Proportioning Equipment), foam expansion and drainage time. Results shall be compared with system specification and manufacturers' data.

Top Pourer Systems - Cone Roof Tanks and Internal Floating Roof Tanks

Top pourer systems are foam systems that consist of one or more foam generator/pourer assemblies positioned around the tank just below the roof to shell seam. On system actuation foam is fed through the generator to the inside of the tank shell to flow onto the fuel surface. They can be regarded as an alternative to base injection systems for cone roof tanks but are not the preferred option because there is a high probability that the equipment will be damaged prior to system actuation.

They are, however, the system of choice for internal floating roof tanks and may be considered for cone roof tanks where base injection or semi-subsurface (see Base Injection Systems) are not considered practical.

Top pourer foam systems shall be designed in accordance with NFPA 11 in terms of application rate, running times, foam discharge velocities and number of foam application points.

Top pourer foam systems for internal floating roof tanks shall be designed to cover the complete fuel surface at application rates for standard cone roof tanks unless it can be shown that the internal floating roof will maintain its integrity in a fire incident.

Each foam pourer assembly will comprise a foam generator, a vapour seal (to prevent vapours from the tank migrating through the foam system



pipework) and a pourer assembly inside the tank to direct foam against the inside wall of the tank.

The foam pourer assembly shall be designed such that a full flow foam discharge test can be carried out without breaking the vapour seal and without discharging foam into the tank.

A separate foam solution riser shall feed every foam pourer assembly. Every foam pourer assembly shall be clearly marked with operating pressure and flow rate.

Foam solution system pipework shall incorporate valves such that individual risers to foam pourer assemblies can be isolated in the event of damage to an assembly. The valves shall be located such that radiant heat levels as predicted by FRED, do not exceed 5 kW/m2 under credible fire scenarios (nb. full surface fires in internal floating roof tanks are not generally considered credible scenarios - fires burn at the vents only).

The foam solution pipework shall be provided with pressure gauges at convenient locations to check operating pressures. The minimum operating pressure required shall be clearly identified at the pressure gauge.

The system shall be fully fixed for FERM strategy 3 & 4 facilities. They can be supplemented by semi-fixed. In the case of semi-fixed systems the inlets shall be positioned such that the radiation level limits given for proportioning systems for fixed foam systems are met.



In semi-fixed systems, the foam solution inlets shall be clearly marked with their purpose, the tank number to which they relate, the minimum operating pressure and flow rate.

All foam systems shall be discharge tested on an annual basis. The tests shall include proportioning accuracy, foam expansion and drainage time. Results shall be compared with system specification and manufacturers' data.

Extended Discharge Foam Systems for Protection of Rimseal Areas on Floating Roof Tanks

Reference should be made to DEP 80.47.10.31, General, Paragraph 2.4.1.3.

In this case, the term extended discharge refers to a system having a discharge time in accordance with a recognised standard such as NFPA 11 (i.e. it is not a one shot system providing a short duration application of foam as provided in the following section).

The extended discharge system shall be considered as the primary protection system even when a one shot system is also in place. Thus a one shot system is not considered to be an alternative to the extended discharge system.

The system shall comply with the requirements of NFPA 11 in terms of foam solution application rate, run time and number of foam application points.

The systems shall not be automatically actuated from a detection system.

The system shall be designed such that it can be actuated manually, either locally or remotely, within 10 minutes of a confirmed fire. If this cannot be achieved, a one-shot foam system shall also be provided as detailed in the following section.

For new facilities, the system application devices shall be of the top pourer type because it allows easy inspection and testing. The system consists of a number of foam generators and pourers mounted around the top of the tank fed with foam solution from the proportioning unit. Each pourer assembly shall be provided with a foam generator (i.e. a single foam generator feeding several pourers shall not be permitted).

The alternative of a "Coflexip" system, consisting of a number of foam generators mounted on the roof fed from an array of pipework that includes a flexible pipe internal to the tank, may be maintained if already installed on existing plant.

The primary systems shall be fully fixed but may be supplemented by semi-fixed systems when there is ready access to a professional fire brigade. When semi-fixed systems are installed, the system inlets shall be outside the bund and clearly marked with their purpose, the tank to which they relate and minimum operating pressure and flow rate.

All foam generators shall be clearly marked with their minimum operating pressure and the flow rate at that pressure.



A foam dam shall be installed on the tank to contain the foam over the seal area. This dam shall be designed and provided with drain holes in accordance with NFPA 11. The fitting of the foam dam to the roof shall be such that leakage of foam or foam solution cannot occur except at the designated drainage points (i.e. there will be a dam tank roof seal or continuous weld except at drainage points).

Hydrant outlets fed with foam solution shall be provided at the top of the tank at wind girder level to allow use of foam hand lines to supplement the fixed system. The maximum distance between foam solution hydrants shall be 60m around the walkway.

A pressure gauge shall be provided on the foam system pipework along with clear identification of the minimum operating pressure at this point.

A cabinet including 2 x 20m x 65mm hoses and a 450 lpm foam nozzle shall be provided at each hydrant outlet on the walkway.

Foam application devices shall be of the aspirating type.

Drain facilities shall be provided in the system to allow the complete system to be drained after operation.

Foam application devices shall be designed or provided with screens so as to minimise the possibility of blockage from external sources such as birds nesting.

Foam pourers shall be designed and mounted on the tank shell so that foam is directed to flow down the inside wall of the tank without disruption from the tank structure or fittings.

All foam systems shall be discharge tested on an annual basis. The tests shall include proportioning accuracy (see 4.6.3.6), foam expansion and drainage time. Results shall be compared with system specification and manufacturers' data.

One Shot Foam Systems for Floating Roof Tank Rimseals

A one-shot foam system for floating roof rimseals is a self contained detection and protection system intended to provide a fast response to rimseal fires by early detection and automatic discharge of foam into the rimseal area. It must be emphasised that one-shot systems are regarded as a first strike system that should detect and extinguish a rimseal fire before it spreads significantly around the tank circumference. They should not be regarded as an alternative to the extended discharge system described in the previous section, which should be regarded as the primary protection method.

One shot systems shall be a totally integrated package comprising linear heat detection, alarm/control facilities, foam concentrate storage, water storage (or premix storage - see below), foam solution discharge pipework and discharge nozzles.

The detector system shall comprise a continuous heat detector mounted around the entire circumference of the tank at a distance of 50mm



maximum from the top of the seal assembly. Each foam solution module shall have its own dedicated detector in the segment it protects.

The heat detector shall be either of the fusible plastic tube type (see DEP 32.30.20.11 - General, November 1995, Paragraph 3.9.4.2) or digital electrical cable type. Frangible bulbs mounted on a ring of pressurised pipework shall not be acceptable.

On detection of the fire, a dedicated alarm will sound in a permanently manned location and at the tank area. Visual alarms shall be clearly identified with the number of the tank to which they refer (all detectors from individual modules on a tank can be connected to a common alarm).

All electrical components shall be suitable for the classification of the area in which they operate, recognising that the roof area should be regarded as Zone 1.

Foam solution application rate shall be 20 lpm/m2 around the seal area and

shall be discharged for a minimum period of 30 seconds.

Foam application nozzles shall be positioned such that the areas of the rimseal affected are blanketed with foam within a period of 15 seconds from the system actuation.

Aspirated foam nozzles are preferred in order to provide a more effective blanket than non-aspirating nozzles.

The circumference of the tank shall be split into segments of approximately 40m. The foam application nozzles in each segment shall be fed with foam solution from a dedicated supply module. The discharge pipework and detector for neighbouring modules shall overlap by at least one nozzle spacing distance.

Foam solution discharge pipework shall be stainless steel or other material that reduces maintenance requirements on the tank roof.

The foam solution shall be supplied from modules which contain either premix (i.e. foam concentrate and water already mixed) in a pressure vessel or a separate foam concentrate and water storage.

On actuation of the detector, automatic discharge of the relevant tank segment module shall automatically occur by pressurisation of the unit. The pressurisation cylinder shall be external to the premix (or water) vessel for easy inspection and maintenance.

A sunshade to prevent direct exposure to sunlight shall protect each storage module.

In cases where the foam concentrate and water are stored in separate vessels, the proportioner shall be of a type that can still function correctly with 3 nozzles blocked.

All foam systems shall be discharge tested on an annual basis. The tests shall include proportioning accuracy, foam expansion and drainage time. Results shall be compared with system specification and manufacturers'



data. In addition, rimseals on the system shall be fully discharged and replenished on an annual basis.



5.3.5 Foam Deluge Systems

Foam deluge systems comprise an array of open headed discharge nozzles located around or above the hazard. They are all operated simultaneously and fed from a fixed proportioning system. Semi-fixed systems are not practicable because the intention of a foam deluge system is to provide very rapid response to contained spill fire situations and develop a foam blanket to prevent re-ignition. Connection of a proportioning system at the time of the fire would give unacceptable delays.

Foam deluge systems shall be designed in accordance with NFPA 16 using an area foam solution application rate of 6.5 lpm/m2 and a minimum of 10 minutes application time, followed by water for a total time of 60 minutes at an application rate of 6.5 litres/m2/min. With an increased application rate the operating time may be reduced proportionally, but not less than 7 minutes.

Foam deluge systems shall be fed with foam solution from a fixed proportioning system.

Foam deluge system nozzles shall be of the aspirating type.

The foam deluge system nozzle shall be such that following foam application, continuing water application for a period of 20 minutes will provide a cooling spray capability without significant damage to the foam blanket.

5.3.6 Portable Foam Application Equipment

Hand held foam nozzles shall be aspirating nozzles of the type requiring foam solution to be fed to them (i.e. they shall not be the type that incorporates a proportioner).

Foam nozzles for use on small spill fires (e.g. minor bund incidents) at FERM strategy 3 facilities shall have approximately 200-250 lpm throughput at 7 barg inlet pressure. Their throughput shall be matched to that of the proportioners used with them (see Proportioners for Hand Held Foam Nozzles).

Foam nozzles for use at FERM strategy 4 facilities shall have a throughput up to 1000 lpm at 7 barg inlet pressure.

Hand held foam application equipment shall be provided in fire cabinets at strategic locations adjacent to hydrants at FERM strategy 3 and 4 facilities. The number and location of fire cabinets shall be determined from hazard identification and pre-fire planning studies for minor incidents taking into account manning levels.

Each fire cabinet shall contain 1 x foam nozzle (200-250 lpm), 1 x water nozzle (450 lpm at 7 barg jet/spray type) 2 x 20m x 65mm hose lengths and 6 x 20 litre drums of foam concentrate.

FERM strategy 3 and 4 facilities shall be provided with portable foam monitors for use by the fire fighters for larger spill incidents and supplementing fixed systems.



The number of units shall be based on the requirements of any tanks that are not protected by a fixed or semi-fixed system. In the event that all tanks are provided with a system, a single unit shall be provided.

Each foam monitor shall have a throughput of at least 2500 lpm at 7 barg inlet pressure. Monitors shall be provided with a self-inducing proportioning capability but in general shall actually be operated from a specialist vehicle proportioning system.

5.4 Fine Water Spray Systems

These systems shall be designed in accordance with NFPA 750.

5.5 Gaseous Extinguishing Agent Systems

The design of and type of extinguishant used in these systems requires the approval of the custodian of this specification. Halon shall not be used. Reference should be made to DEP 80.47.10.10, General, and NFPA 2001.

5.6 Portable Extinguishers

5.6.1 General

Portable extinguishers shall be suitable for the type of fuel involved in accordance with BS EN 2. There are four classes of fire, namely Class A involving solid materials, Class B involving liquids, Class C involving gases and Class D involving metals.

5.6.2 Standards for Portable Fire Extinguishers

All fire extinguishers shall be manufactured, tested and certified to conform to BS 5423 or equivalent (such as CEN-EN 3.1/2/3/4/5, NFPA 10, Din 14406).

Additionally, the extinguisher body, filling nozzle and cap shall be made from material having rigidity, durability and resistance to electrochemical corrosive effects of the extinguishing media. Non metallic materials are not acceptable for these parts or the moveable nozzle.

Fire extinguishers shall be selected, installed and maintained in accordance with BS 5306 Part 3.



6.0 Alarms and Executive Actions

6.1 General

The table in Appendix D gives typical alarm and executive action requirements for the different types of detection and facilities. This table provides only an overview and the engineer shall fully review the requirements of this specification to define specifics for any piece of equipment.

6.2 Gas Turbines

The required shut down logic associated with turbine hoods is dictated by the sequence of a limited number of possible events:

Given the ingestion of gas into the combustion or ventilation air intakes, the turbine shall be tripped and the hood ventilation system shall be shutdown.

Given a sufficiently large release of flammable gas under the hood, the turbine shall be tripped together with a remote fuel gas ESDV, but the hood ventilation system shall be allowed to run to minimise the possibility of gas concentration build up and result in a possible explosion or flash fire.

Given a confirmed flame detected under the hood, the turbine and ventilation system fans will be tripped together with closure of fire damper(s).



FIGURE 6.2

A generic cause and effect diagram follows:

CAUSE

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Flammable >=1 at ALERT XFlammable any 1 at DANGER

X

Flammable >= 2 at DANGER

X X X X X

Gas Detection(at Air Intakes if HL gas possible)

Flammable >=1 at ALERT XFlammable any 1 at DANGER

X

Flammable >= 2 at DANGER

X X X X X

Fire Detection

>= 1 Heat activated X X X X X X X XAny 1 UV/IR activated X>= 2 UV/IR activated X X X X X X X X

Loss of Hood Ventilation Air Flow* X XLoss of Hood Ventilation Air Flow>= 20 secs*

X X X X

Notes:1. Alert and danger are defined in section 4.22. HL refers to high level



7.0 Abbreviations

AFFF Aqueous Film Forming Foam

AFP Active Fire Protection

API American Petroleum Institute

BPD Barrels Per Day

BS British Standard

CBA Cost Benefit Analysis

CFDH Corporate Functional Discipline Head

CSN Committee European de Normalisation (for Standardisation)

DEP Design Engineering Practice

EN Europaische Norm

EP Engineering Practice

ESD Emergency Shutdown

ESDV Emergency Shutdown Valve

FES Fire and Explosion Strategy

FERM Fire & Explosion Risk Management

FFFP Film Forming FluoroProtein

FM Factory Mutual (Certifying Authority in USA)

FQB Frangible Quartzoid Bulbs

FRED Fire, Release, Explosion and Dispersion

FWS Fine Water Spray

GRP Glass reinforced Plastic

HSE Health, Safety and Environment

ISO International Organisation for Standardisation

ICAO International Civil Aviation Organisation

IPF Instrumented Protective Function

IR Infra Red (the frequency of light used for fire detection and gas detection)

LEL Lower Explosive Limit (Synonymous with LFL)

LFL Lower Flammable Limit (Synonymous with LEL)

LNG Liquefied Natural Gas

LPC Loss Prevention Council

LPG Liquefied Petroleum Gas

MAC Manual Alarm Callpoint

NDT Non Destructive Testing

NFPA Nation Fire Protection Association



PDO Petroleum Development Oman

PLC Process Logic Controller

ppm parts per million (a ratio by volume or mass of one substance in another)

PV Present Value (some future value discounted to today’s value)

QRA Quantified (or Quantitative) Risk Analysis

SIEP Shell International Exploration and Production

SSV Sub Surface Valve

SCSSV Surface Controlled Subsurface Safety Valve

UEL Upper explosive Limit (synonymous with UFL)

UFL Upper Flammable Limit (synonymous with UEL)

UL Underwriters Laboratories Incorporated

UV Ultra Violet (the frequency of light used for fire detection)

VESDA Very Early Smoke Detection Apparatus (VESDA is a trade name)



8.0 References

1. Report No. HSE/97/07 (1997) Fire and Explosion Risk Management (FERM) Summary Report. Petroleum Development Oman

2. Report No. EWE-28107.1 (1996) Halon Phase-out Studies, Quantified Risk Assessment & Cost-benefit Analysis. Electrowatt Engineering

3. Report No. EWE-63273.1/1 (1997) Quantified Risk Assessment for Shipping Pumps and Cone roofed Tanks. Electrowatt Engineering

4. Fire Protection Study Report. Resource Protection International

5. Review of Emergency Services at PDO Airfields, TSE/R/01, 1995

6. FERM Facility Plan Guideline, GU230, 2002.



APPENDIX A - Relevant Standards, Specifications & CodesThe following standards, specifications and codes can provide further information if required.

PDO Standards Title Referred to in Section

· ERD 00-01 PDO Guide to Technical Standards and Procedures

General

· ERD 00-02 Technical Authorities System 2.4.2· ERD 08-04 Safety Aspects of Plant Design for

Sour Service4.4.1

· ERD 08-11 Isolation Process Equipment 3.2.33.2.33.2.3

· ERD 09-02 Spacing of Tanks & Tank Bunding Requirements

3.2.33.2.3

· ERD 10-04 General Specification for Detail Design and Engineering of Oil & Gas Facilities

4.3.24.3.34.3.44.3.6

· ERD 17-02 Fire Detection and Alarm Installation 3.4.1· ERD 30-03 Instrumentation Standard Drawings 4.3.3· ERD 38-12 Requirements - GRE

Pipes/fittings5.1.1

· ERD 48-01 Painting and Coating Systems 5.1.2



Relevant Standards, Specifications & Codes (continued)

SIEP Standards Title Referred to in Section

· DEP 30.48.30.31-Gen

Cement Linings in New Pipelines (1990) MFEC/1

5.1.1

· DEP 31.29.02.11-Gen

Pumps - Selection, Testing and Installation (1983) MFEE/1

5.1.3

· DEP 31.29.02.30-Gen

Centrifugal Pumps (Amendments/Supplements to API Std. 610) (1990) MFEE/1

5.1.3

· DEP 32.30.20.11-Gen

Fire, Gas and Smoke Detection Systems MFTX/51

5.3.4

· DEP 32.80.10.10-Gen

Classification and Implementation of Instrumented Protected Functions

4.1

· DEP 32.80.10.30-Gen

PLC Based Instrumented Protective Systems

4.1

· DEP 33.66.05.31-Gen

Electric Motors-Cage Induction and Synchronous Type (1995) MFEE/3

3.2.3

· DEP 34.17.10.31-Gen

Laboratories (1983) MFEC/1 3.4.5

· DEP 80.47.10.10-Gen

Fire-fighting Agents (1991) MFEO/1 5.3.15.5

· DEP 80.47.10.30-Gen

Assessment of the Fire Safety of Onshore Installations (1995) MFEO/1

3.2.43.2.45.1.5

· DEP 80.47.10.31-Gen

Active Fire Protection Systems and Equipment for Onshore Facilities (1992) MFEO/1

5.1.15.2.15.2.25.3.15.3.45.3.4

· DEP 80.47.10.32-Gen

Movable Fire Fighting Equipment for Onshore Applications (1997) MFEO/1

3.5.25.1.45.1.5

· DEP 80.47.10.33-Gen

Fire-fighting Vehicles and Fire Stations (1993) MFEO/1

5.3.15.3.3

· EP92-1820 Shell Report: Fire Retardant Rim Seal Materials for Floating Roof Tanks. SIEP EPO/61

3.2.3

· EP95-0352 HSE Manual: Quantitative Risk Assessment SIEP

2.5.1



Relevant Standards, Specifications & Codes (continued)

International Standards

Title Referred to in Section

· BS 336 British Standards:1989: Specification for Fire Hose Couplings and Ancillary Equipment. BSI Publication

5.1.4

· BS 476 Parts 4

British Standards:1984: Non-combustible test for materials. BSI Publication

3.4.4

· BS 476 Part 7

British Standards:1993: Method for classification of the surface spread of flame of products. BSI Publication

3.4.4

· BS 5306 Part 2

British Standards:1990: Specification for Sprinkler Systems

5.2.1

· BS 5306 Part 3

British Standards:1985: Code of Practice for the Selection, Installation and Maintenance of Portable Extinguishers. BSI Publication

5.6.2

· BS 5423 British Standards:1995: Specification of Portable Fire Extinguishers. BSI Publication

5.6.2

· BS 5839 Part 1

British Standards:1988: Fire Detection and Alarm Systems for Buildings. Part 1 Code of Practice for System Design, Installation and Servicing. BSI Publication

4.3.7

· BS 5839 Part 2

British Standards:1983: Specification for Manual Alarm Call Points. BSI Publication

3.4.14.4.1

· BS EN 2 British Standards:1992: Classification of Fires (replaces Code of Practice for Classification of Fires:1972) BSI Publication

5.6.1

· NFPA 10 National Fire Codes: Portable Fire extinguishers. Vol.1. National Fire Protection Association.

5.6.2

· NFPA 11 National Fire Codes: Standard for Low-Expansion Foam. Vol.1. National Fire Protection Association.

5.3.15.3.35.3.35.3.45.3.45.3.4

· NFPA 13 National Fire Codes: Standard for the Installation of Sprinkler Systems. Vol.1. National Fire Protection Association

5.2.1

· NFPA 15 National Fire Codes: Standard for Waterspray Fixed Systems for Fire Protection. Vol.1. National Fire Protection Association

5.2.2

· NFPA 16 National Fire Codes: Standard on Deluge Foam-Water Sprinkler and Foam-Water Spray Systems. Vol.1. National Fire Protection Association

5.3.15.3.5

· NFPA 20 National Fire Codes: Standard for the Installation of Centrifugal Fire Pumps. Vol.1. National Fire Protection Association

5.1.3



· NFPA 22 National Fire Codes: Standard for Water Tanks for Private Fire Protection. Vol.1. National Fire Protection Association

5.1.2

· NFPA 750 National Fire Codes: Standard on water mist fire suppression systems. National Fire Protection Association

5.4

· NFPA 2001 National Fire Codes: Standard on Clean Agent Fire Extinguishing Systems. National Fire Protection Association

5.5

· ICAO-9137 Part 1

Airport Services Manual, Rescue and Fire Fighting. ICAO (International Civil Aviation Authority)

3.5.1

· ICAO-9137 Part 7

Airport Services Manual, Airport Emergency Planning. ICAO (International Civil Aviation Authority)

3.5.1

· ISO 7203-1 Fire Extinguishing Media, Foam Concentrates 5.3.15.3.2

· UL 162 Foam Equipment and Liquid Concentrates, 7th

edition5.3.15.3.2



APPENDIX B - Assessment of Business Risk Due To Fire and ExplosionThe risks due to fire and explosions of existing typical assets in PDO have been assessed and plotted onto a ‘Risk Matrix’ as shown below.

This matrix gives an overview of the risk level of typical equipment to provide an indication of the level of protection that may be justified in the form of a fire and explosion strategy.

The individual equipment risks are positioned to denote the worst case frequency and consequences. Some equipment appears twice, e.g. a floating roof tank fire has occurred in SIEP with minor (rating 2) consequences but elsewhere in the industry with very serious (rating 5) consequences.

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ppen

s se

vera

l tim

es a

ye

ar a

t lo

cati

on

Rat

ings

Peo

ple

Ass

ets

Env

iron

me

nt

Rep

uta

tion

Pro

duc

tion

A B C D E

No injury

Slight injury

Minor injury

Major injury

Single Fatality

Multiple Fatality

No Damaage

Slight Damage

Minor Damage

Local Damage

Major Damage

Extensive Damage

No Effect

Slight Effect

Minor Effect

Localised Effect

Major Effect

Massive Effect

No Impact

Slight Impact

Limited Effect

Considerable Impact

National Impact

International Impact

No Effect

Slight Effect

Minor Local Effect

Major Local Effect

Massive Effect

Total Extended

Effect

0

1

2

3

4

5

Consequence

Probability of Occurrence

1

5 7 8

9

3

4 6

2

2 7

4 6

Strategy 1 Strategy 3

Strategy 1/2 Strategy 4

Strategy 2 Strategy 3/4

Strategy:Incident:

1. Small Incidents2. Pump Seals3. Compressors4. Turbine Enclosures5. Pressure Vessels

6. Cone Roof Tanks7. Floating Roof Tanks8. Aircraft9. Camps



APPENDIX C - Facility Group CategoriesProduction and gathering stations have been categorised according to the facilities and level of risk as follows:.

Production Stations

Category A: Typical facilities include:ManifoldsSmall cone roof tanksCompressors and turbine enclosuresPumpsSubstationControl room

Specific hazard fire protection is to be provided at Category A production stations without a firewater network (strategy level 2).

Category B: Typical facilities include those on Category A stations but also have larger cone roof tanks and pressure vessels.

Specific hazard fire protection is to be provided at Category B production stations with a firewater network (strategy level 3). Category C: Typical facilities include those on Category B stations but also have floating roof tanks.

Specific hazard fire protection is to be provided at Category C production stations with a fire water network (strategy level 3).

CATEGORY AREAB LekhwairC YibalC FahudC Qarn AlamB Rima PSA Sayyala PSB Nimr PSB MarmulA AnzauzA SuwaihatA ZauliyahA Ghubar



Gathering Stations

Category A: Typical facilities include:ManifoldsSeparatorsPumpsSmall cone roof tanksSubstationControl Room

First aid fire protection is only to be provided at Category A stations (strategy level 1).

Category B: Typical facilities include those on Category A stations but also compressors and turbine enclosures.

Specific hazard fire protection is to be provided at Category B stations without a fire water network (strategy level 2).

CATEGORY AREA CATEGORY AREAB Al Huwaisah B Marmul AA Lekhwair B A Marmul BB Yibal B A Marmul CB Yibal C B Marmul DA Yibal D A Marmul EB Fahud B B Marmul GB Fahud C A QaharirB Fahud D A RahabB Fahud E A ThamoudB Fahud F A ThuleilatB Natih B BirbaB Qarn Alam A Nimr CA Barik A Nimr BA Burhaan A Nimr AB Ghaba North A AmalA Qarat Al Milh B Saih NihaydaB Saih Rawl A SadadB Bahja By passed Hasirah



APPENDIX D - Typical Alarms and Executive Actions

Hazard Type of Detector

Equipment Type Facility Type

Gath Station

Prod Station

Booster Station

Power Station

MAF GGP

Fire Heat Crude oil/ condensate shipping pumps

X X X N/A X X

Compressors X X N/A N/A N/A XFixed roof tanks X X N/A N/A X N/AFloating of tanks N/A X N/A N/A X N/ATurbine enclosures X X X X N/A XDiesel generator N/A N/A X X N/A Alarm & ESDFuel gas skid Fired heater skids

X X X X X Alarm & ESD

Flame Crude pumps X X N/A X X XCompressors X X N/A N/A N/A XTurbine enclosures X X X X N/A X

Smoke Control rooms X X X X X XAuxiliary rooms X X X X X XElectrical rooms X X X X X XComputer rooms N/A N/A N/A N/A X N/ATurbine hall N/A N/A N/A X N/A N/AOffices X X X X X X

Gas Comb Gas

Turbine enclosure (air intake)

X X X X N/A X

Gas compressors X X N/A N/A N/A X



Fuel gas skid X X X X N/A X



Typical Alarms and Executive Actions (continued)

Type of Detection Alarm/Action Facility Type

Gath Station

Prod Station

Booster Station

Power Station

MAF GGP

Heat GFS panel alarm XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

Mimic panel alarm X X X X X X

Area sirens/bells X X X X X XESD associated equipment X X X X X XBlowdown associated equipment (Note 4)

X X X X X X

Station ESD X XNote 1

X XNote 1

Initiate AFP (Note 3) X X X X X XAlarm to SCADA X X X X X XAlarm to fire brigade X

Flame GFS panel alarm XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

Mimic panel alarm X X X X X XArea sirens/bells X X X X X XESD associated equipment X X X X X XBlowdown associated equipment (Note 4)

X X X X X X

Station ESD X XNote 1

X XNote 1

Initiate AFP (Note 3) X X X X X X



Alarm to SCADA X X X X X XAlarm to fire brigade X

Smoke GFS panel alarm XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

Mimic panel alarm X X X X X XArea sirens/bells X X X X X XIsolate associated non essential power supplies

X X X X X X

Alarm to SCADA X X X X X XAlarm to fire brigadeAssociated AC trip X X X X X X



Typical alarms and executive actions (continued)

Type of Alarm/Action Facility TypeDetection

Gath Station

Prod Station

Booster Station

Power Station

MAF GGP

Comb Gas Alert GFS panel alarm XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

Mimic panel alarm X X X X X XArea sirens/bellsESD associated equipmentBlowdown associated equipment (Note 4)Station ESDAlarm to SCADA X X X X X XAlarm to fire brigade

Comb Gas Danger

GFS panel alarm XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

Mimic panel alarm X X X X X XArea sirens/bells X X X X X XESD associated equipment X X X X X XBlowdown associated equipment (Note 4)Station ESD X X

Note 1X X

Note 1Isolate non essential power supplies

X X X X X X

Alarm to SCADA X X X X X X



Alarm to fire brigadeToxic (H2S) GFS panel alarm

Mimic panel alarm X X X XArea sirens/bells X X X XAlarm to SCADA X X X X

Manual call Point

GFS panel alarm X Note 2 X Note 2 X Note 2 X Note 2 X Note 2 X Note 2

Mimic panel alarm X X X X X XArea sirens/bells X X X X X XStation ESD X X

Note 1X X

Note 1AFP activated GFS panel alarm X

Note 2XNote 2

XNote 2

XNote 2

XNote 2

XNote 2

Mimic panel alarm X X X X X XAlarm to SCADA X X X X X X

Notes 1. Station ESD not required if station is permanently manned.2. Alarm required on GFS panel if no mimic provided, typically for control/auxiliary buildings.3. Initiate AFP on relevant equipment where installed.4. Where blowdown facility is provided.



Appendix E - Worked Examples

The Specification provides a methodology for determining the levels of fire and explosion protection for what are seen as critical items of equipment, ie. cone roofed tanks and shipping pumps.

This approach is based on a detailed QRA (Reference 3) which was performed, and enables the user to apply a cost benefit analysis in order to justify the protection level specified.

Some worked examples are provided below.

Cone Roofed Tanks

Suppose we are installing 2 new oil storage tanks at Marmul, and wish to establish what levels of fire protection can be justified. The production rate for Marmul is 63000 BPD, and using the pro-forma on page 18 of this Specification:

BASE CASE COST OF DAMAGE CALCULATION PRO-FORMASystem Constant based on frequency of damage x days lost:

(3.75x10-4

x 486 =)

0.18225


Net Oil Production per pair of tanks in BPD (e.g. for 5 tanks divide the total production by 2.5) For an installation with a single tank multiply the total production by 1.39 (to compensate for the loss of total production given the loss of a single tank)

x 63000

= Base Case Annual Cost of Damage per Tank = $ 22964x Number of tanks covered by Protection 2= Base Case Annual Cost of Damage for Installation =

$ 45927

x Design Life of the Installation 20= Undiscounted Design Cost of Damage for Installation =

$ 918540


Value at Discount Rate

Years 5% 8% 10%10 0.772 0.671 0.61720 0.621 0.490 0.42625 0.564 0.427 0.36230 0.512 0.376 0.313 0.490

Base Case PV of Cost of Damage for Installation $ 450085

The risk reduction by installing heat detection and base foam injection is provided on the risk histogram (Figure 3.2.3), and works out as 64% (ie, 100-36). Therefore, 0.64 x 450085 = US$288054 can be spent installing



heat detection and base foam. If the cost of installing the fire protection is less that US$288054, then installation is justified.



Shipping Pumps

Suppose we are installing 3 additional centrifugal shipping pumps at Yibal A and wish to establish the levels of fire protection that can be justified. Assuming that the 3 pumps have a combined capacity of 23000 BPD, and using the pro-forma on page 18 of this Specification:

BASE CASE COST OF DAMAGE CALCULATION PRO-FORMA System Constant based on frequency of damage x days lost for 3 pumps:

(3.18x10-4

x 130 x 3 = )

0.12402

Pump Type for centrifugal/axial or screw pumps use x 1for reciprocating pumps use x 10

x 1

Number of Pumps in Set for 2 pumps use x 0.6for 3 pumps use x 1.0for 4 pumps use x 1.46for 5 pumps use x 2.0

x 1


Net Oil Production for Pump Set in BPD x 23000= Base Case Annual Cost of Damage per Pump Set = $ 5705x Design Life of the Pump Set 20= Undiscounted Design Cost of Damage for Pump Set =

$ 114098


Value at Discount RateYears 5% 8% 10%10 0.772 0.671 0.61720 0.621 0.490 0.42625 0.564 0.427 0.36230 0.512 0.376 0.313 0.490

Base Case PV of Cost of Damage for Installation $ 55908

The risk reduction by installing fire detection is provided on the risk histogram (figure 3.2.3) and works out as 67% (ie. 100-33). Therefore, 0.67 x 55908 = US$37459 can be spent installing fire detection. If the cost of installing the fire protection is less than US$ 37459, then installation is justified.


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