29

Directive for aboveground storage of flammable liquids in vertical cylindrical tanks

PUBLICATION SERIES

HAZARDOUS SUBSTANCES

Issued by Maarten Nouwens

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VROM Ministry of Housing, Spatial Planning and the Environment Directorate of External Safety

Rijnstraat 8

P.O. Box 20951

2500 EZ The Hague

www.vrom.nl

Publication Series Hazardous

Substances 29

Directive for aboveground storage

of flammable liquids

in vertical cylindrical tanks

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Preface

As per June 1, 2004, the Advisory Council Hazardous Substances (AGS) was appointed by the government. The Committee of Prevention of Disasters due to hazardous substances (CPR) was also discontinued. The CPR issued publications, the CPR Directives, that are often used when

licenses are granted in pursuance of the Environmental Management Act and within the fields of

work safety, transportation safety, and fire safety.

The CPR Directives were converted into the Publication Series Hazardous Substances. The object

of these publications is roughly the same as of the CPR Directives, notably to give an overview,

based on the status of technology, of the regulations, requirements, criteria and conditions that can

be applied by authorities when granting licenses to and supervising companies that work with

hazardous substances. When converted into PGS publications, all CPR Directives were evaluated from the following questions:

- is there still a reason for the directive to exist or can the directive be cancelled, and - can the directive be copied without amendment or is it necessary to update it.

This publication is an update and combination of the directives:

- CPR 9-2 LIQUID PETROLEUM PRODUCTS, aboveground storage small installations and - CPR 9-3 LIQUID PETROLEUM PRODUCTS, underground storage large installations

After this conversion, the PGS 29 was subsequently amended in connection with the explosion

and fire in the Buncefield fuel depot in British Hemel Hampstead. An expert task force consisting

of government and industry translated and processed the investigation results and

recommendations of the Buncefield investigation into the Netherlands approach.

The input for this work consists of three reports:

- Recommendations on the design and operation of fuel storage tanks 03/2007, issued by the Buncefield Major Incident Investigation Board (BMIIB);

- Recommendations on the preparedness for, response to, and recovery from incidents 07-2007, issued by BMIIB;

- Safety and environmental standards for fuel storage sites 07-2007, issued by the Buncefield Standard Task Force Group (BSTG)

The PGS 29 has been prepared within the structure of the CPR by the sub-committee Storage liquid petroleum products. The Interprovincial Committee (IPO), the Association of Netherlands Municipalities (VNG), and the business community (VNO-NCW and MKB the Netherlands) had already given a positive advice earlier on issuing this publication.

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table of contents

1 Introduction

1.1 Amendments new directive compared to CPR 9-2/3 1.2 Starting points

2 Object, field of application, and use 2.1 Object of this directive 2.2 Field of application

2.2.1 In General 2.2.2 Exceptions for substances 2.2.3 Exceptions for activities

2.3 Use of this directive

3 Definitions and terms

4 Tank storage, activities, and design

4.1 Activity

4.2 Design of the site

4.3 Mutual distances

4.4 Sewage system and drainage

4.5 Electrical installation and grounding

4.5.1 Electrical installation

4.5.2 Grounding

4.5.3 Measures against static electricity

4.6 Danger zone design

4.7 Hydrogen sulfide

5 Tank farm containment areas

5.1 Permitted activities in the tank farm containment area

5.2 Minimum distances within the tank farm containment area

5.3 Collecting capacity of the tank farm containment area

5.4 Construction of the tank farm containment area

5.4.1 Tank farm containment area floor

5.4.2 Dikes

5.4.3 Ducts

5.4.4 Access to the tank farm containment area

5.5 Sewage system

5.6 Drainage of firewater

5.7 Product pump in the tank farm containment area

5.8 Pipes and shut-off valves in the tank farm containment area

6 Storage tanks 6.1 General requirements

6.1.1 Construction

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6.1.2 Calculation bases 6.2 Access to tank roofs 6.3 Tank equipment

6.3.1 Aerating a tank with a fixed roof 6.3.2 Aerating a tank with a floating roof 6.3.3 Seal materials and workable ranges of seals 6.3.4 Shut-off valves 6.3.5 Anchors 6.3.6 High-level alert and overfill protection

6.4 Non-destructive examination of welds after new construction of tanks

7 Other facilities 7.1 Vapor processing installation and/or vapor return system 7.2 Pump-pads 7.3 Transfer

7.3.1 General requirements 7.3.2 Tank trucks and train tank wagons (loading and unloading stations) 7.3.3 Ships (piers)

7.4 Product pipes and pipe tracks 7.5 Product shut-off valves 7.6 Utilities 7.7 Offices, workshops, and laboratories 7.8 Control rooms

8 Firefighting facilities 8.1 In general 8.2 Fire extinguishers 8.3 Firewater system

8.3.1 Capacity of firewater system 8.3.2 Design of the firewater system 8.3.3 Firewater pump system

8.4 Refrigerating systems 8.5 Foam extinguishers 8.6 Fire detection 8.7 Report and alert facilities 8.8 Other facilities

9 Safety control measures 9.1 Safety policy 9.2 Staff: skill, training, alertness 9.3 Scenario description and accident analysis 9.4 Supervision over the execution 9.5 Being prepared for and respond to emergency situations

9.5.1 Procedures and instructions 9.5.2 Incident and accident report 9.5.3 Drill

9.6 Cooperation 9.6.1 Supervision over performances

9.7 Assessment and evaluation

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10 Fire prevention and safety 10.1 Tests upon delivery

10.1.1 Installation pipes 10.1.2 Tank heating

10.2 Independent supervision 10.3 Inspection program 10.4 New construction certificate 10.5 Safety systems

11 Business operations and management 11.1 Operational supervision and inspection 11.2 Work permits 11.3 Periodical inspection and maintenance

11.3.1 In general 11.3.2 Inspection of tanks

11.4 Maintenance fire safety facilities 11.5 Waste 11.6 Documentation and document management

12 Change management 12.1 Introduction of changes (organizational and technical) 12.2 Reporting changes 12.3 Implementing consequences of changes

13 Termination and putting out of operation

References

Annex A: Additional recommendations for tank foundations

Annex B: Additional recommendations for tank constructions

Annex C: Standards for tank installations

Annex D: Distance tables from the codes of the Institute of Petroleum (IP) (ref. 44)

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1 Introduction

1.1 Amendments new directive compared to CPR 9-2/3

Compared to the directives CPR 9-2 and CPR 9-3, some amendments were made to this revised

directive, the most important of which are mentioned briefly hereinafter.

For installations for liquids of class 3 with a tank storage capacity under 150 m3, the directive

CPR 9-6 will apply. For tanks with a capacity under 150m3 for liquids of classes 1 and 2, this

PGS-29 can be used. The international tank construction standards are also applicable to the

smaller tanks. In consultation with the competent authority and the Fire Department, parts of this

directive can also be applied to these smaller tanks.

In this revised directive, the division into (fire) classes has been adjusted to the European

Directive 67/543/EEC [Ref. 41]. This adjustment does not have consequences in practice. The

terms K1, K2, and K3 have been abandoned; they are replaced by classes 1, 2, 3, and 4,

respectively, also used in the directive CPR 9-6. See Chapter 3, Definitions and terms, under

Class for this purpose.

In this revised directive, a distinction is made between the following four types of storage (see

Chapter 3, Definitions and terms):

1. tanks with a fixed roof;

2. tanks with a floating roof;

3. tanks with a fixed roof with an internal floating roof;

4. tanks with a supported geodesic roof, also with an internal floating roof.

Wherever possible, reference has been made to international standards and codes.

By the publication of this directive the directives CPR 9-2 and CPR 9-3 will be cancelled.

1.2 Starting points

The starting point is that storage tanks meet at least one of the existing international standards or

codes for tank construction of API 650 [Ref. 4], BS 2654 [Ref. 22], and DIN 4119 [Ref. 32] in

revisions as they were applicable at the time of construction, and in case of new construction NEN

EN 14015-1 [Ref. 70] (in as far as relating to atmospheric tanks). Also other Netherlands

directives, such as the NRB [Ref. 82] (BoBo guideline) and the NeR [Ref. 48] (containing KWS 2000 [Ref. 46]), apply, but they are not part of this directive. The same applies to covenants.

When necessary or useful, reference is made to other standards and codes, for instance that of

NFPA and AI sheets.

The regulations (laws and Implementation Decrees) have direct effect and do not need to be

inserted in directives and licenses.

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2 Object, field of application, and use

2.1 Object of this directive

The object of this directive is in general reducing safety risks. In a more narrow sense, this

directive intends to be a clear reference framework for the business community as well as the

competent authority for the erection, use, preservation, and inspection of installations with vertical

tanks. This is mainly of importance, because undesired incidents can lead to serious accidents

within and outside the establishment and to serious pollution of air, soil, and water. The directive

is of importance to the government for the granting of licenses, to the business community for the

design of installations.

A second function of this directive is to contribute to the harmonization of safety requirements of

several license-granting agencies to different companies.

2.2 Field of application

2.2.1 In general

This directive is applicable to establishments with at least one vertical, cylindrical, aboveground

tank the floor of which rests on a foundation and in which flammable liquids of classes 1, 2, and 3

are stored under atmospheric pressure, and for substances of class 4 that are stored while heated.

Substances that are stored at a temperature equal to or higher than their flashpoint have to be

treated as a substance of class 1.

This directive is also, but with additional requirements, if necessary, applicable to flammable

liquids that also belong to another risk category.

For these flammable liquids that can, for instance, also be poisonous, harmful, corrosive, or

conducive to burning, other or additional requirements can also apply, which have to be laid down

per case in the environmental permits. Examples of these substances from practice are acrylic

nitrile and methanol (both poisonous).

The risk categories to be used are those as laid down in the Chemical Substances Act [Ref. 93]

and the European Directive 67/543/EEC [Ref. 41] and its amendments.

2.2.2 Exceptions for substances

This directive is consequently not applicable to:

- compressed gases and/or gases made liquid by refrigerating, for instance propane and butane; - liquids of class 0. However, within class 0, there are liquids that have a vapor pressure (TVP)

of a maximum of 500 mbar when stored under atmospheric circumstances.

This directive can be applied to the following, at the discretion of the competent authority:

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- non-flammable liquids, such as watery solutions of inorganic substances, aerosols, foams, etc.; - flammable liquids with a flashpoint of over 100oC that are not heated, or that are stored and

transferred while heated, provided that the temperature of the liquid remains at least 20oC

below the flashpoint;

- storage of liquids of class 3 as referred to in the directive CPR 9-6 [Ref. 29].

2.2.3 Exceptions for activities

The term establishment corresponds with the term establishment as used in the Environmental Management Act [Ref. 92], and the Implementation Decrees belonging thereto (see Chapter 3:

Definitions and terms). Often there is question of complex establishments where also other

activities than tank storage and the transfer belonging thereto take place. Examples hereof are:

- storage in other tanks than those this directive relates to, such as tanks for the storage of gases compressed to liquid, underground tanks, horizontal tanks, and smaller tanks;

- storage of vessels and mixed cargo; - production processes; - activities other directives apply to.

This directive basically only relates to the part of an establishment where the storage of liquids

and the activities directly related to it, such as transfer and transfer by pumps, take place.

In complex cases, doubts can arise about what directives or standards apply to what sections. In

those cases, consultation between the operator and the competent authority has to lead to

agreement.

The directive does not apply either to the transportation of flammable liquids that falls under

transportation regulations.

2.3 Use of this directive

This directive will be used in practice by the business community and license-granting agencies.

The regulations of this directive do not exclude the use of other systems, methods, or instruments

with equal or better quality, strength, fire resistance, effectiveness, durability, or safety, provided

that the equality has been proven to the competent authority and the systems, methods or

instruments suggested in deviation from this directive are suitable for the application suggested.

These deviations have to be approved by the competent authority.

The regulations of this directive do not have direct effect, but are only applicable if and in as far as

they have been included in environmental permits.

This directive is also applicable when changes to existing establishments are granted. The

competent authority has to take into account that in this situation, when using this directive,

several regulations cannot be applied or only in part. Of course this applies to the regulations for

new construction and regulations that affect the infrastructure and working method granted in the

past. In these cases it is up to the competent authority to judge what regulations can be included in

reason.

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3 Definitions and terms

1. Petroleum product Product from a petroleum refinery.

Examples are naphtha, gasoline, kerosene, white spirit, diesel oil, domestic fuel oil, fuel oil. Also

catalytic cracked products of the refinery and natural gas condensate are considered petroleum

products.

2. Atmospheric storage The storage is considered to be atmospheric if the absolute pressure above the liquid is under 1.06

bar during storage.

3. Control measure

Actions, programs, procedures of an organizational or administrative nature with the object to

perform the necessary acts to protect safety and the environment. Also called measure.

4. Flammable (liquid) substance

A liquid that is flammable itself or from which a flammable gas, flammable vapor, or flammable

mist can arise (EN-IEC 60079-10) [Ref. 39].

5. Fire-safety plan Collection of all data on fire risks in a company or organization and on the measures and facilities

present to reduce these risks as much as possible.

6. Fire Department The governments fire department

Explanation:

If the subject is firefighting, Fire Department is understood to be the repressive service of the Fire

Department. If it concerns advice, the Fire Chief of the municipal or regional fire department or his

representative is meant.

7. Chemicals Within the framework of this directive, chemicals are understood to be:

1. (petro)chemical products of petroleum products, which have been created by chemical conversion or by thermal cracking.

2. flammable liquids of biochemical origin, for instance ethanol. Inorganic chemicals in liquid form or dissolved in water or emulsified are consequently not

chemicals in the sense of this directive.

8. Vapor pressure The absolute pressure in bar, determined in accordance with the standard NEN EN 12 [Ref. 65]

with the Reid device.

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9. Vapor return system

A system meant to catch vapors that would otherwise be released into the atmosphere on account

of displacement losses and to return them without processing to the tank from which one pumps.

10. Vapor processing system

A system meant to catch and process vapors that would otherwise be released into the atmosphere

on account of displacement losses (including breathing losses).

11. Diameter for tank distances

If the diameter (D) of a tank is used to indicate mutual distances between tanks, the diameter of

the largest tank in the tank farm containment area is meant, unless indicated otherwise.

12. Operator

The one who operates the establishment or who is liable for operating the establishment. Mostly

this is the holder of the environmental permit.

13. Explosive atmosphere

Explosive atmosphere as defined in NPR 7910-1 [Ref. 81].

14. Explosion range

The explosion range of a stored product is defined by the circumstances under which the product

has a vapor pressure (and vapor composition) at which the vapor-air mixture is explosive. This

range is between the lower and upper explosion limit.

Explanation:

The lower explosion limit is the lowest vapor concentration at which the vapor-air mixture can be ignited

as yet, after which this mixture burns down without energy supply from outside.

The upper explosion limit is the highest vapor concentration at which the vapor-air mixture can be ignited

as yet, after which this mixture burns down without energy supply from outside.

Below the lower explosion limit the mixture has too few, and above the explosion limit it has too many

flammable vapors to be able to keep it burning.

To determine explosion limits, see the Chemiekaartenboek of TNO Arbeid [Ref. 24] and the Association Netherlands Chemical Industry (VNCI) 2003 [Ref. 89].

15. Foundation

The foundation the tank rests on, for instance risen foundation.

16. Geodesic roof

Self-supporting domed tank roof.

17. Danger zone

The area where flammable vapors can occur under normal circumstances. This area corresponds

with the term danger zone of the standard EN-IEC 60079-10 [Ref. 39] and NPR 7910-1:2001 [Ref. 81]. The area beyond it is a non-danger zone.

18. Installation

Permanent technical unit within which one or more activities take place and all other activities

directly connected to them that are technically related to the activities performed within this unit.

Explanation:

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An establishment can consequently consist of several installations: tank farm containment areas, offices,

plants, transfer areas, etc. are individual installations.

19. Establishment

Each activity undertaken by humans commercially or with a scope as if it were commercial, which

is usually performed within certain boundaries.

20. Class

This directive mentions class 0, class 1, class 2, class 3, and class 4.

Table 3.1 provides the division into classes.

Table 3.1: Division into classes with regard to fire hazard

Class Flashpoint limits Examples

Class 0 Flashpoint (FP)

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Collecting capacity of the tank farm containment area is the capacity of the tank farm containment

area under the lowest height of the surrounding dike or wall, reduced by the volume inside that is

absorbed by other (smaller) tanks, risen foundations, dividing dikes, and appurtenances.

28. Product pipe

All pipes that are connected with the tank content, such as suction pipes and filling pipes.

29. Dike

A liquid-barrier wall around a tank farm containment area that can provide for collection of

product from the storage tank(s) and of a possible amount of (fire)water. A dike can consist of a

wall of earth/sand/clay, a steel or concrete wall, or another (liquid-barrier) construction. A dike

can be the partition between a tank farm containment area and the surroundings and between a

tank farm containment area and an adjacent tank farm containment area.

30. Compounds

Parts of a tank farm containment area separated from each other by one or more dividing dikes

(compounds).

31. Disaster or serious accident

An incident:

- that has caused a serious disturbance of public safety, by which life and health of many persons are seriously threatened or have been seriously harmed, and;

- for which a coordinated effort of services and organizations of various disciplines is required to remove the threat or limit the harmful effects.

32. Fracture joint

A weak joint between tank wall and tank roof, created intentionally, meant to yield first in case of

fire or explosion.

33. Tank

In the sense of this directive, a tank is an aboveground, vertical, cylindrical container the tank

floor of which rests on a foundation. Tanks have the function to provide for storage capacity for

transportation, delivery, or commercial purposes, or as interim storage in a production process. No

new substances are produced in the tanks with chemical reactions. However, by mixing, stirring,

or heating, (mixtures of) substances can be brought up to delivery specification or mixtures can be

separated by sedimentation or stratification in tanks.

Within the framework of the field of application of this directive, four types of tanks can be

distinguished.

1. tanks with a fixed roof (tapered or domed), whether or not with a support construction for the

roofing sheets;

2. external floating roof tanks;

3. tanks with a fixed roof as referred to in 1, and provided with an internal floating roof (internal

floating roof tanks) and provided with:

- open vents or- pressure vacuum valves;

4. tanks with a self-supporting domed roof, based on a geodesic design, whether or not provided

with an internal floating roof.

34. Group of small tanks

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A group of small tanks as referred to in IP code, Volume 19.

35. Tank farm containment area

A part of the site surrounding a storage tank that provides for collection of product or (fire)water

by sunken installation or a surrounding closed wall (dike).

36. Foundation

The foundation of the tank.

37. Site boundary

The boundaries of the establishment as referred to in the definition of the term establishment.

Explanation:

On the side of the land, this is usually fencing. On the side of the water there is often no other barrier than

the water itself.

38. Dividing dike

A facility dividing the surface of the tank farm containment area, with the object to prevent liquid

from spreading over the total surface of the tank farm containment area in case of a minor leak. A

dividing dike can consist of a wall of earth/sand/clay, a steel or concrete wall, or another (liquid-

barrier) construction. Also called: dividing dam.

39. Vertical cylindrical tank

A vertical cylindrical vessel the tank floor of which rests on a foundation.

40. Flashpoint

The temperature of the liquid at which a flammable mixture can be created (flashpoint) with air,

just above the liquid.

The flashpoint up to 55oC is determined in accordance with the Abel-Pensky method, described in

NEN EN ISO 13736 [Ref. 69].

The flashpoint over 55oC is determined in accordance with the Pensky-Martens method, described

in NEN EN ISO 2719 [Ref. 66].

The flashpoint of substances and/or mixtures stored while heated has to be determined based on

the ASTM D3941-90(2001) [Ref. 15]. Determining whether the fire is self-sustained can be done

by means of the ASTM D4206-96(2001) [Ref. 16].

Explanation:

If it concerns a mixture of substances with a changing composition, one has to take the flashpoint of the

substance with the lowest flashpoint that constitutes at least 10% (volume) or more of the mixture at any

time.

41. Liquid-proof facility

A facility aimed at effect that guarantees that subject to the condition of efficient maintenance and adequate inspection no liquid can get to the side of this facility that does not contain liquid.

42. Liquid-barrier facility

A facility that is not liquid-proof, which is capable of temporarily barring substances released for

so long that they can be cleaned up before they can penetrate into the soil.

43. Facility

Technical equipment meant to:

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- meet the operational objectives; - improve and guarantee safety and protection of the environment.

44. WBDBO

Fire transfer resistance and fire spread resistance in minutes. See NEN 6068 [Ref. 64].

45. Zone

Zone 0: an area within which an explosive atmosphere is present continuously or during long

periods of time. See NPR 7910-1:2001 [Ref. 81]

Zone 1: an area within which the chance of presence of an explosive atmosphere is

substantial under normal operations. See NPR 7910-1:2001 [Ref. 81].

Zone 2: an area within which the chance of presence of an explosive atmosphere is small

under normal operations and within which such an atmosphere, if present, will only

exist for a brief period of time. See NPR 7910-1:2001 [Ref. 81].

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4 Tank storage, activities, and design

This directive specifies the facilities and control measures required that are applicable to

establishments where storage of flammable liquids in aboveground, cylindrical storage tanks takes

place.

Regulations that only apply to installations with liquids of classes 1 and 2 have explicitly been

indicated.

Specific control measures have been indicated with the facilities in question. The general control

measures have been described in Chapter 8 through 13 of this directive.

4.1 Activity

In the establishment, activities can take place that consist of storage and transfer of liquid

chemicals and/or mineral oil products in aboveground storage tanks, tank trucks, and ships. The

activities that take place in an establishment can be subdivided into:

- storage of products, liquid waste, waste water, and ballast water of ships; - loading and unloading of ships, tank trucks, train tank wagons, and tanks; - transfer from ship to ship; - transfer of products by pumping through external pipelines; - degassing and cleaning of tanks and pipelines; - butanization of products; - filtering, mixing, and homogenization of products; - adding of additives; - heating of products; - washing of products.

The establishment can dispose of the following buildings and facilities:

- tank park; - tank farm containment areas; - piers; - loading and unloading area for tank trucks; - pump platforms; - pipelines; - hoses; - vapor processing systems; - buildings, including:

offices; mobile work and storage units; warehouse buildings; workshops; service buildings; security booth;

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group of huts/sheds;

sample rooms;

low-high voltage areas;

gas bottle storage space;

gas reception and reduction station;

boiler houses;

transformer buildings;

- fire departments training area; - waste collection areas; - emergency power facilities; - compressed air system; - drinking water facility; - sewage system; - lighting; - roads.

4.2 Design of the site

Demarcation of the site

1. The site where the establishment is located has to be surrounded at any rate on the land sides

by an efficient fence. The construction and height hereof has to be such that access to the site

other than through the entrances is discouraged.

Entrances

2. In connection with the accessibility of the installations for emergency services, the

establishment has to be accessible through at least two entrances located as far apart as

possible. Depending on the local situation and the possibilities, this may be deviated from in

consultation with the Fire Department. The entrances in the fence have to be kept closed as

much as possible. Open entrances have to be supervised at all times.

Road plan

3. The road plan has to be drawn up and approved in consultation with the competent authority

and the Fire Department.

Explanation:

The road plan supports a traffic circulation plan that adequately separates the various forms of

transportation on the site and counters unnecessary transportation movement.

4. The road plan has to be designed in such a manner that at all times the installations, tank farm

containment areas, and buildings can be reached without obstruction by at least two separate

roads. Tank farm containment areas have to be adjacent to roads that are suitable for driving

on at least two sides. Additional requirements are found in the municipal building ordinance.

Lighting of the site

5. There has to be lighting on the site that facilitates proper orientation, normal activities during

the night, and security.

Landscaping

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6. No fire-hazardous trees or bushes are to be found on the storage site of the establishment within a distance of 15 m from a tank farm containment area or loading or unloading area for

liquids.

7. The plants cannot obstruct firefighting.

8. Except on undeveloped land, weeds and grass will be kept short. Dry wood, leaves, and cut weeds or grass have to be removed immediately. The use of weed killers is only permitted if

this does not constitute a fire hazard.

Maintenance

9. All roads, dikes, fencing, buildings, and other facilities on the site of the establishment have to be in a good state of repair.

10. The site of the establishment have to be kept clean.

11. Materials that are not used and waste have to be removed or stored on parts of the site designated for this purpose, if possible in special containers.

4.3 Mutual distances

The fire-safety requirements of this directive are based for the larger part on the IP code, Volume

19.

12. In new installations and in case of changes to installations, the minimum distances between the various parts of the installation have to comply with the codes of the Institute of Petroleum

[Ref. 44].

Explanation:

As an illustration, according to the IP codes for liquids of classes 1, 2, and 3, the distances

between parts of installations are listed in Annex D. They do not apply to substances such as

bitumen and only if the tank farm containment areas are provided with additional

requirements, such as access roads over the dike. This table serves as an illustration. For

accurate interpretation of the distance rules one has to consult the IP codes.

The distances in the IP codes are recommendations. Designers have to use them as a guideline.

The competent authority may deviate from the distances recommended, provided that safety is

adequately guaranteed by provisions and measures.

13. Buildings with vital functions, the proper functioning of which also has to be ensured in the event of a fire, such as transformer buildings and storage spaces for firefighting materials,

should not be located in a danger zone. If these buildings contain heating installations that

suck in outside air, the places where this combustion air is sucked in have to be located on the

side facing away from a danger zone.

14. The distance of filling spaces, filling areas, pump houses, and storage spaces for packed products of classes 1 and 2 has to be at least 15 m to:

- storage spaces for storage of vessels of products of classes 1 and 2; - the site boundary; - the interior crest line of a tank farm containment area;

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- a building in which one can work with fire or in which open fire can be present, such as workshops and welding spaces.

15. Operating buildings in which open fires or ignition sources are present, such as workshops for

maintenance, service buildings, and boiler houses, have to be located in a non-danger zone.

16. Heating boilers installed in the outside air have to be located in a non-danger zone.

17. In all cases, the combustion air for the fires has to be sucked in on the side facing away from a

danger zone; the doors of a boiler house have to be installed in the side of facing away from a

danger zone.

18. Office buildings have to be located in a non-danger zone. Openings through which outside air

is sucked in for heating installations have to be located on the side facing away from a danger

zone. These buildings have to consist as much as possible of inflammable building materials.

Preferably, the buildings have to be located in such a manner that access for the public is

provided without passing the exterior fence.

19. The distances referred to in this Chapter may be deviated from, provided that it has been

proven by a risk analysis approved by the license-granting agencies that smaller distances can

suffice.

4.4 Sewage system and drainage

20. In consultation with the competent organizations, one has to see to effective facilities for the

discharge of drainage and rainwater and other possibly polluted water from tank farm

containment areas, piping routes, pump areas, loading and unloading areas and the like.

Explanation:

a. Discharge from tank farm containment areas: see paragraphs 5.6 and 5.7.

The discharge of drainage and rainwater from tank farm containment areas in surface water or in a

public sewage system can only be done through efficient oil or liquid separators. Underground,

closed parts of these sewer pipes have to be kept filled with water in order to prevent risk of

explosion.

b. Discharge from other parts of the site belonging to the tank installation:

- Drainage and rainwater coming from places where product leaks can be expected (forinstance pump areas and piping routes) has to be discharged through an efficient oil or

liquid separator before discharge in the surface water or public sewers takes place, in

conformity with the license in pursuance of the Pollution of Surface Waters Act or the

Environmental Management Act.

- Risk of explosion in underground sewer pipes can be prevented by keeping them filled with water.

- All other underground sewer pipes have to be installed with a gradient. - Drainage, rainwater, and domestic waste water coming from places where no product leaks

are expected can be discharged through a separate sewage system, in conformity with the

license in pursuance of the Pollution of Surface Waters Act or the Environmental

Management Act.

4.5 Electrical installations and grounding

4.5.1 Electrical installation

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21. The entire electrical installation has to comply with the regulations of the standards: - EN NEN 500110 [Ref. 40]; - NEN 3140 [Ref. 54].

Explanation:

In a danger zone the electrical installation also has to comply with the statutory regulations arising

from the European ATEX directives concerning Equipment and safety systems on locations where there may be a risk of explosion [Ref. 18], and Protection of workers who are at risk due to an explosive atmosphere [Ref. 19]. These directives have been contained in Netherlands legislation in the Dangerous Equipment Act [Ref. 94] and the Explosion-safe Equipment Decree [Ref. 20].

22. It has to be possible to shut down the electrical installation within a danger zone in all poles and phases by means of one or more switches that are placed in a non-danger zone.

23. On or near each switch, the destination and the switch positions have to be clearly indicated.

4.5.2 Grounding

24. A storage tank has to be grounded in conformity with the standards NEN 1010 [Ref. 49] and NEN 1014 [Ref. 50].

25. Installation of the grounding and the testing hereof has to take place in conformity with NEN 1014 [Ref. 50] by an accepted expert, approved by an accredited organization. The expert has

to provide a certificate of the grounding installed.

26. The grounding has to be tested once every five years by an expert measuring leakage resistance, which expert has been accepted by the competent authority.

27. In case of a tank diameter exceeding 6 m at least two grounding cams have to be present; the mutual distance over the periphery of the tank wall cannot be more than 20 m.

28. Permanently conductive stainless steel strips with a minimum width of 30 mm have to be affixed to internal or external floating roof tanks between the roof and the tank wall. The

number of strips depends on the installed type of seal. The minimum distance between the

strips is 2 m for vapor mounted seals and liquid mounted seals. In case of mechanical shoe

seals, one strip per shoe plate has to be affixed.

Explanation:

When a rolling ladder is present, the cable can be connected between the ladder construction and the

access platform (to bridge the hinges) on the one side and the ladder construction and the rails (to

bridge the wheels) on the other side.

29. For internal floating roof tanks, grounding cables have to be affixed between the tank and the floating roof in conformity with NEN-EN 14015-1 [Ref. 70], Annex C. For external floating

roofs, Annex D of NEN-EN 14015-1 applies.

4.5.3 Measures against static electricity

30. When transferring products that can be charged electrostatically according to ASTM-D-4865-96 [Ref. 17] and NFPA 77 [Ref. 78] by pumping, the velocity in the pipelines has to be limited

to 1 m/s in the following cases:

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- if various products (of the same class) are pumped through the pipe, separated by water; - if a product is displaced in the pipe by water; - if one pumps in an empty or almost empty tank; - if one can expect the product to have been polluted by water, air, or solid particles. This limited velocity has to be kept up until the entire pipe contains only one liquid, but at

least for half an hour. A higher filling velocity is only permitted after one has made sure that

aforementioned cases do not present themselves. In the event of an empty or almost empty

tank, the limited velocity has to be kept up until the liquid level in the tank is at least 0.50 m

above the inlet opening.

4.6 Danger zone design

Measures for explosive atmospheres

The directive NPR 7910-1 [Ref. 81] sets rules for the design of workplaces where an explosive

atmosphere may occur.

Explanation:

The Working Conditions Decree obligates employers to evaluate the risks in connection with explosive

atmospheres and the special risks that may arise from same within the framework of the risk inventory and

risk evaluation before the start of the work and upon each important change, expansion, or alteration of the

workplace, the work equipment, or the work process as a whole. This evaluation has to be recorded in

writing in an explosion safety document.

If the evaluation shows that there can be an explosive atmosphere, areas of where an explosive

atmosphere can be are divided into danger zones as referred to in Annex I of the NPR 7910 [Ref.

81].

Furthermore, the Working Conditions Decree obligates employers to take general, specific, and

special measures related to explosive atmospheres or the risk hereof.

4.7 Hydrogen sulfide

31. For the storage of substances that can contain hydrogen sulfide (H2S), an H2S policy has to be

in place. This policy has to contain regulations concerning:

- design starting points, for instance application of closed drains, minimizing holdups, safedeaeration;

- H2S detection systems, both permanent detection systems (for instance in pump-pads) and personal monitoring systems;

- procedures, for instance: the identification of H2S containing equipment;

opening of H2S containing equipment;

sampling;

pyrophoric ferric sulfide;

safe drainage;

- emergency instruction regarding the release of an H2S cloud; - personal means of protection, the application, instruction, training, and maintenance; - first aid in case of accidents with or exposure to H2S.

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5 Tank farm containment areas

5.1 Permitted activities in the tank farm containment area

32. A tank farm containment area cannot contain any form of storage than tank storage, except for collection of rainwater in an open drainage system.

33. No materials can be stored or present nor can installations be found in the tank farm containment area, other than tanks with appurtenances, pipes, and transportation pumps, if

any, unless and as long as these materials are necessary in the tank farm containment area for

maintenance and/or repairs.

34. Maintenance and or repairs can only be performed in the tank farm containment area after a work permit has been granted for this purpose.

5.2 Minimum distances within the tank farm containment area

35. If tanks with fixed roofs and tanks with floating roofs have been installed in one containment area, the provisions for tanks with fixed roofs will apply to all tanks in that tank farm

containment area, without prejudice to the specific provisions for floating roof tanks.

36. If a storage tank for products of class 3 is placed in a tank farm containment area that also contains storage tanks for products of classes 1 or 2, the distances and the rules for the storage

of products of classes 1 and 2 will apply to the entire tank farm containment area.

5.3 Collecting capacity of the tank farm containment area

The collecting capacity of the tank farm containment area has to equal at least the content of the

largest tank augmented by the larger of the following two volumes:

- 10% of the volume of the other tanks in this tank farm containment area; - the volume of firewater that can be brought into the tank farm containment area in one hour,

according to the capacity required in the license.

5.4 Construction of the tank farm containment area

5.4.1 Tank farm containment area floor

37. The tank farm containment area floor has to be above the highest groundwater level.

5.4.2 Dikes

Dike height

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38. The height of the dike is determined by the necessary collecting capacity of the tank farm

containment area, augmented by 0.25 m for possibly occurring gusts of wind, augmented by

the maximum setting of the dike to be expected locally until the next height inspection.

Explanation:

So when determining the height, one does not have to take into account a storm surge arising when a

tank collapses.

In order to limit the polluted surface and evaporation of pools and thermal radiation from a burning

pool in case of small leakage or spillage, it is of importance to keep the liquid surface within a tank

farm containment area limited by compartmentalizing the tank farm containment area by means of

dividing dikes.

For the capacity of the compounds and the height and construction of the dividing dikes, no regulations

are given. Of course, dividing dikes have to meet the objects set for same.

Liquid-barrier

39. The side of the dike at the tank farm containment area and the tank farm containment area

floor have to constitute a liquid-barrier.

40. The complex of containment area floor and dike has to be in conformity with the Netherlands

Soil Protection Guidelines (NRB) [Ref. 82].

Strength

41. The dike has to be constructed so strong and stable that it can resist the maximum liquid

pressure to be expected for quite some time. During the construction one has to take into

account the load-bearing capacity of the subsoil, adjacent roads and embankments, ducts, and

dike passages and settings, if any.

Fire resistance

42. The fire resistance of the dike has to be adjusted to the maximum scenario to be expected.

Inspection and maintenance

43. Dikes have to be inspected and maintained so often that the minimum height and liquid-barrier

remain guaranteed.

44. Damage found has to be repaired immediately.

45. Turfs of dikes have to be kept short.

5.4.3 Ducts

46. Ducts of pipes through dikes have to be avoided as much as possible.

47. Ducts through a dike have to be a liquid-barrier, fire resistant, resistant to the maximum

hydrostatic pressure to be expected and resistant to the substances stored. Ducts have to be

adequately strong and flexible to be able to absorb expected setting of pipes and dikes.

5.4.4 Access to the tank farm containment area

48. Tank farm containment area floor and dikes have to be protected in such a manner, for

instance by means of steps and accesses and crossings and walkways, that damage in case of

repeated access for inspection, sampling, and loading/unloading actions is prevented.

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Explanation:

For the access to the tank farm containment area with vehicles and materials for maintenance, one may

choose from the following options:

- preferably a crossing over the dike; - a passage construction through the dike; - the temporary excavation of part of the dike.

49. A crossing over the dike has to be adequate solid for the transportation to be expected and leave the primary function of the dike intact. The crossing has to be closed for traffic, unless a

work permit has been granted for the use.

50. A passage construction through the dike has to meet the same requirements of solidity, height, liquid-barrier and fire resistance as the dike. The construction has to be closed, unless a work

permit has been granted for the use. The maximum capacity present in the storage tanks in the

tank farm containment area has to be adjusted to the remaining collecting capacity in the tank

farm containment area before the opening of the passage construction. After use, the

construction has to be closed in such a manner that the requirements for the dike are met

again.

51. When part of the dike is temporarily excavated, the maximum capacity present of the storage tanks in the tank farm containment area has to be adjusted to the remaining collecting capacity

in the tank farm containment area before the excavation. After the activities, the dike has to be

restored in such a manner that the excavated part and the connection to the non-excavated part

of the dike meet the original requirements. A work permit has to be issued for excavating the

dike.

5.5 Sewage system

52. Each tank farm containment area or compound has to be provided with a drainage and sewage system that works independently from the sewage system of other tank farm containment

area(s) and/or tank farm containment area compound(s).

53. The shut-off valve meant for controlled drainage of water from the tank farm containment area has to be affixed outside the tank farm containment area and be kept closed. The shut-off

valve can only be open during controlled drainage of water. The position of the shut-off valve

has to be visible on the outside. The sewage system has to be equipped with a facility that

facilitates inspection of possible pollution of the water to be drained at all times.

Explanation:

Controlled drainage of rainwater from the tank farm containment area can also take place by means of

pumps. Automatic switching of the pumps is not permitted (manual control).

54. The duct of the sewer pipe through the dike has to be fire resistant, resistant to the maximum hydrostatic pressure to be expected, and resistant to the substances stored.

55. The sewers, the sewer pipe and the duct of the pipe through the dike cannot affect the liquid-barrier of the tank farm containment area floor and the dike.

56. The capacity of the sewage system has to be adjusted to the maximum amount of rainwater to be expected.

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57. The discharge of drainage and rainwater from tank farm containment areas into the surface

water or a public sewage system can only take place through efficient oil separators or liquid

separators.

5.6 Drainage of firewater

58. Each tank farm containment area should have a facility enabling the fire-safe drainage of

firewater. This facility has to be installed in such a manner that undesired transfer of the

firewater present in the tank farm containment area is not possible.

59. When a tank farm containment area is divided into compounds, each compound has to be

equipped with its own drainage facility.

60. If a power point or manual operation for the drainage of firewater is used, this power point or

this manual operation has to be outside the thermal radiation contour of 3 kW/m2.

5.7 Product pump in the tank farm containment area

61. In certain cases the competent authority may permit that a pump for product transportation is

set up in the tank farm containment area near the storage tank. This pump then has to meet the

following requirements:

- the electric motor of the pump cannot touch the surface of the liquid in the tank farm containment area on account of an incident with a storage tank;

- if the mechanical part of the pump is of a type with which, when the source of power fails, the flow of liquid can return through the pump body and lead to an increased risk, this pump has

to be equipped with a non-return valve on the outlet side;

- the pump has to stand on a liquid-tight concrete floor.

62. The electric motor of the pump has to meet the following safety requirements:

- electrical installation made in conformity with Eexd CT4;- maximum temperature of the electric motor

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65. Joints (flanged joints, flexible couplings, and bellows) have to be avoided as much as possible. The use of hoses for product transportation in the tank farm containment area is not permitted.

66. Shut-off valves in a tank farm containment area meant for transportation of liquids of classes 1 and 2 have to be fire-safe (at least the code ASME B16.5 [Ref. 11]) or similar. The shut-off

valves have to be equipped with product-proof and fire-safe gaskets. On the outside it has to

be clearly visible whether a shut-off valve is open or closed.

67. Pipes and their construction for fire-safety systems have to be equipped with passive protection, for instance by a foaming coating.

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6 Storage tanks

6.1 General requirements

68. Tanks to be newly built have to meet the European standard NEN EN 14015-1 [Ref. 70]. For deviation from the above standard, approval is required from an organization accepted by the

competent authority.

Explanation:

Apart from the environmental permit, the tank installations also have to meet the Rules for pressure

appliances. According to these rules, an independent organization has to issue a certificate of

investigation and testing (BOB) in case of new construction.

69. When evaluating whether existing tanks are still suitable to be able to fulfill their primary function the storage of a product (Fit-for-Purpose analyses), the degradation limits as referred to in the EEMUA publication No. 159 [Ref. 34] have to be followed.

70. Reconstruction, moving, adjustment, or repair of an existing tank has to be in conformity with: - the code API 653 [Ref. 5], if the tank has been designed in accordance with the code API 650

[Ref. 4];

- the EEMUA publication No. 159 [Ref. 34], if the tank has been designed in accordance with the standard BS 2654 [Ref. 22].

71. The once chosen standard or code has to be used consistently. It is not permitted to use various standards or codes for a tank and to select the most favorable regulations from same.

72. The welding method has to be in conformity with the tank construction standard concerned or EN 288-3 [Ref. 37], and has to be approved by a controlling organization recognized by the

competent authority before welding is begun. The welding has to be carried out in conformity

with the approved welding method and has to be done by previously qualified welders.

6.1.1 Construction

Annex A to this directive contains recommendations for the foundation. There are no other

standards or codes for it.

Annex B to this directive contains additional recommendations for the construction of tanks that

supplement the codes referred to in paragraph 6.1.

6.1.2 Calculation bases

73. The dimensioning basis of a new storage tank has to be in conformity with the standard NEN EN 14015-1 [Ref. 70], as soon as it has been ratified by the government. Pending this

ratification, newly built tanks have to meet the standards or codes API 650 [Ref. 4], BS 2654

[Ref. 22], or DIN 4119 [Ref. 32]. The construction drawings with the calculations belonging

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thereto have to be submitted for evaluation to an organization accepted by the competent

authority. Roofs supported by columns cannot be used.

74. To determine the wind load in accordance with the draft standard concerned, the wind velocity is fixed at 45 m/s for tanks to be set up in the Netherlands.

75. When calamities cause excessive excess pressure, the tank construction has to be such that the connection of the wall to the floor cannot yield and that the tank wall also remains intact.

Explanation:

This has to be met by giving the top side of the tank a fracture joint. If a fracture joint cannot be

realized (see also API 650, Annex F [Ref. 4], and BS 2654 [Ref. 22], Annex F) and NEN EN 14015-1

Annex K [Ref. 70], the following measures have to be taken:

- Calculations have to prove that the connecting welds of the tank floor/tank wall are stronger than the connecting welds between tank wall and tank roof, or:

- One or more emergency vents have to be applied, the necessary capacity of which has been determined in accordance with the code API 2000, section 4.3.3.2 [Ref. 7].

- In consultation with the competent authority, it has to be determined whether, in addition to the emergency vent(s), the tank has to be operated with an inert gas cover.

- For tanks with a diameter < 12.5 m the directives of the EEMUA publication No. 180 can be followed as an alternative [Ref. 35].

The joint roof platetank wall cannot be too strong, the roof slope cannot exceed 1:5, and the fillet welds cannot exceed 5 mm. In case of modifications to the tank roof, this situation also has to be

maintained.

6.2 Access to tank roofs

76. The access to tank roofs has to meet NEN 14015-1 [Ref. 70].

77. Roofs of tanks being part of a group in one tank farm containment area can also be accessible by the footbridges mutually connecting these tanks. The last tank in a row, seen from the

rising spiral staircase then has to be equipped with an escape (cage) ladder. Depending on the

diameter of the tank or the setup in a tank farm containment area, fixed stairs are required

additionally, the slope angle of which cannot be more than 45 degrees with a step width of at

least 0.60 m.

78. External floating roof tanks can never be connected with each other by footbridges.

6.3 Tank equipment

6.3.1 Aerating a tank with a fixed roof

79. A tank with a fixed roof has to be protected against impermissible under-pressure and excess pressure. For the storage of substances of classes 1 and 2 and heated liquids that have to be

treated as substances of these classes (see 2.2.1), a pressure/vacuum valve has to be applied of

such design that the following requirements are met:

- the adjustment pressures by which the valve opens have to be chosen in such a manner that the pressure in the tank cannot go beyond the maximum or the minimum design pressure,

also in case of maximum transfer;

- raining in and freezing over cannot occur;

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- no flame arrestors and detonation protections may be affixed to the pressure/vacuum valve(s), if the effluent opening is in connection with the outside air. If the effluent takes

place to a vapor return installation or vapor reclaim installation, flame arrestors and

detonation protections can only be installed in conformity with the design requirements of

the system.

In case of products of class 3, an open connection to the atmosphere is permitted. This open

connection has to be provided with bird-proof grille or wire netting. One has to take into

account the flow-through limit of this grille or wire netting when calculating the minimum

required flow-through capacity of the open connection.

6.3.2 Aerating a tank with a floating roof

Internal floating roof tanks

80. In case of an internal floating roof tank, vents have to be made in conformity with Annex C.3.4.1 of the standard NEN EN 14015-1 [Ref. 70]. Under conditions in which open vents are

not desired in accordance with this standard, the tanks need to have pressure and vacuum

valves, the capacity of which has to be determined in accordance with the API 2000 [Ref. 7].

If calculations prove that an explosive mixture can regularly exist in the vapor space above the

internal floating roof, pressure and vacuum valves also have to be applied.

Explanation:

When applying internal floating roofs with a low emission limit and with many transfers (fillings and

emptyings in brief periods of time), it can be dangerous to use open vents, as the vapor space is then

regularly filled with explosive mixtures (neither saturated nor non-saturated vapor).

External floating roof tanks

81. External floating roof tanks the products of which contain light fractions that can evaporate (for instance non-stabilized crude oil) need to have pressure valves to prevent gas bubbles

from accumulating under the membrane of single cover roofs or need to have systems by

which the gas can be led to the space between the primary and secondary seal through ducts.

82. If a mechanical shoe seal has been affixed in the crack between the floating roof and the tank wall, rim vents also need to have been affixed the adjusting pressure of which has been chosen

in such a manner that the seal material cannot yield.

6.3.3 Seal materials and workable ranges of seals

83. Seals of internal and external floating roofs have to be made of materials in conformity with the EEMUA 159 directive [Ref. 34]. Moreover, the workable range of the seal needs to have

been chosen in such a manner that it complies with Annex D.3 of the EEMUA 159 directive

[Ref. 34]. The seals have to meet the maximum slits that can occur between the seal and the

tank wall, also indicated in this directive.

6.3.4 Shut-off valves

84. Shut-off valves have to be closed when in rest and placed as close as possible to the tank.

6.3.5 Anchors

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85. Anchors have to be at least of a 4.6 quality with a material strength in conformity with DIN 267 Teil 3 [Ref. 31].

86. In case of gluing of the anchoring, the available anchor strength has to be inspected.

6.3.6 High-level alert and overfill protection

87. Tanks have to be equipped with: a. a high-level alert that raises an alarm on location and/or in the control room, before the

highest permitted liquid level in the tank is reached, so that measures can be taken to

reduce the pump capacity or to stop the transfer by pumps, and;

b. a physically independent instrumental overfill protection that causes the supply to the tank to stop when the highest permitted liquid level in the tank is reached.

The reliability of the instruments and protections has to be in proportion to the safety risk. One

has to use a methodology that proves and documents the relation between the risks,

determined by safety studies, and the (reliability of the) measures (instruments and

protections).

Examples of methodologies:

- SIL methodology in which, depending on the desired risk reduction, requirements are made for the choice and maintenance frequency/type of the necessary regulations and protections;

(NEN EN 61511/61508)

- safety layer methodology, for instance LOPA; - company policy linking the risk to the measure; for instance, for a scenario with a risk

valuation X, at least two independent LODs have to be used to control the risk.

Explanation:

If in case of unloading of ships the second protection is not possible from a technical point of view, it

can be refrained from in consultation with the competent authority or an alternative solution with an

acceptable level of protection can be agreed on.

Physically independent is understood to be:

- independent of level measurement - individual steering signal Overfill protection is understood to be:

- every system that causes the supply to the tank to stop automatically without intervention of an operator.

6.4 Non-destructive examination of welds after new construction of tanks

88. Examining welds with non-destructive detection techniques has to be performed at least in conformity with the requirements of the BS 2654 [Ref. 22], irrespective of what code/standard

has been used for the design of the tank (see paragraph 6.1).

Explanation:

There are differences between the codes with regard to the minimum requirements of (the amount of)

non-destructive examination of welds in tanks. In order to level these differences, one has to use the

requirements of the BS 2654, so that no distinction is made between tanks on one and the same

location. Moreover, the minimum requirements of the BS 2654 with regard to the acceptance of the

competent authority are normative.

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7 Other facilities

7.1 Vapor processing installation and/or vapor return system

89. The design of a vapor return system and/or vapor processing installation has to be substantiated with a safety study. The design and safety study need to be approved by the

competent authority.

Explanation:

It is preferable that in case of vapor processing vapors are reclaimed or converted into electrical energy

or heat for energetic application.

It is crucial that one works in sections that, depending on the nature of the substances and the direction

of the flow, are separated by one-sided or double-sided functioning detonation protection/baffle plate

grilles.

7.2 Pump-pads

The object of a pump-pad is to have a collection of product pumps, shut-off valves, and product

pipes/hoses, where connections can be made between the tanks, between tanks and

loading/unloading areas, and between tanks and piers.

90. The pump-pad has to be made liquid-proof and cannot have a direct connection with a tank farm containment area or sunken pipe track. Pipe ducts through the wall of the pump-pad have

to be avoided as much as possible. If it is not possible in another way, the pipe ducts have to

be made liquid-proof. A liquid barrier pump-pad with ducts is acceptable, provided that a

control system has been attached to it, approved by the competent authority.

Explanation:

As with all other activities, the soil protection of the tank farm containment area has to meet the

Netherlands Soil Protection Guidelines for business premises [Ref. 82].

91. The pump-pad has to be designed in such a manner that switching of product flows with hoses is prevented as much as possible.

92. If possible, the setup location of the product pump is chosen in such a manner that the electric drive of the product pump cannot touch the liquid in case of leakage, if any, in the pump-pad.

93. A facility has to be present in the pump-pad to discharge the rainwater collected in the pump-pad. This facility has to meet at least the same requirements as set for the discharge of

rainwater from a tank farm containment area.

7.3 Transfer

7.3.1 General requirements

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94. Transfer activities can only take place in loading and unloading areas specifically fitted up for this purpose.

95. During loading and unloading, instructions have to be available for safe loading and unloading.

95a During loading and unloading, all protections have to be operational.

95b Protections cannot be bridged, unless this is necessary for safety reasons.

There has to be a protocol/procedure available, guaranteeing the following:

- the tasks, powers and responsibilities with regard to the bridging of protections; - the registration; - the recognizability of bridging by means of signs.

96. The connections of the product pipes to the loading and unloading area have to be designed and/or marked in such a manner that mixing up products during loading and/or unloading is

prevented. For this purpose, each connective point for loading and unloading arms or hoses

has to carry a clearly visible and legible sign or name from which one can derive what product

the connective point is used for. For pipes meant for various substances one may deviate from

it, provided that one uses a procedure that prevents calamities on account of changing the

product.

97. Product pipes of loading and unloading installations that are not in use have to be closed with a blind flange or at least a similar facility, so that leakage, also in case of a malfunction or an

operating error, is prevented. This does not apply to product pipes that do not contain a

product, are clean, and disconnected from the installation.

98. On the transfer location, in the direct vicinity of the transfer location or pier, and in the control room from which the loading and/or unloading process is controlled, an easily accessible

facility needs to be installed to be able to stop the loading as soon as possible (emergency stop

procedure).

99. If television systems are used for supervision during loading and unloading, there has to be an emergency stop procedure that can also be operated from the location where the monitor has

been installed.

100. Cameras on piers have to be installed in such a manner that during transfer activities they can permanently monitor the quay as well as the ship.

101. By internal, written procedures drawn up in advance, one has to see to a proper functioning of the loading and unloading hoses or arms present in the establishment. These

procedures have to pay attention to at least the following elements:

- such support, protection, operation, and storage, that damage is prevented; - the falling or rising of the ship on account of the movement of the tides and the transfer; - inspection of the good condition before the loading and unloading hoses or arms are used; - not using damaged hoses; - examination of reliability by pressure testing at least once every year at at least 1.35 times

the operating pressure. Hoses of third parties can be used in the establishment, provided that

they are inspected once every year in conformity with the prevailing Netherlands standard

NEN EN 12798 [Ref. 68];

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- stamping in the date and quality mark of this pressure testing in a connecting flange or connecting coupling; instead of stamping in date and quality mark, a registration system of

the pressure testing of the hoses can also be created, while a number has been stamped in

the flange or coupling of each hose that corresponds with this registration system;

- registration of the data of this testing and the retention of these data for at least two years.

102. Damaged hoses cannot be stored in the loading or unloading area.

103. If loading and unloading pipes and hoses are emptied after the transfer, facilities have to be installed to let them empty before they are disconnected. The released substances have to be

collected in a system meant for this purpose. For residue of loading that has been left behind

unintentionally, a collection facility has to be available at the disconnection point.

104. Transfer can only take place in accordance with internal, written procedures drawn up in advance, which pay attention to at least the following matters:

- that the staff that takes care of the loading sees to it that the correct identifying marks have been placed on the means of transportation to be loaded, before loading is begun;

- that in the event of transfer of liquids, the operating staff makes sure that, before the transfer by pumps begins, the parts to be used have been installed in such a manner that the liquid to

be pumped can only end up in the place meant for this purpose;

- that the operator, as well as the staff that takes care of the loading, has made sure in advance that the receiving containment (tank, ship) has adequate space/capacity to safely receive the

volume to be transferred (product package).

105. During the loading and unloading of tank trucks and train tank wagons at least one supervisor of the establishment has to be present in the loading and/or unloading area or in the

control room, who has a view of the loading and/or unloading activity and who causes the

transfer to stop immediately in case of malfunctions, leaks and/or irregularities.

7.3.2 Tank trucks and train tank wagons (loading and unloading stations)

106. The loading and/or unloading of a tank truck or train tank wagon on the top side can only take place if there is a loading and/or unloading platform for this purpose or if a facility is

found on the tank truck or train tank wagon that makes it possible to easily reach the

filling/unloading opening of the tank truck or train tank wagon under any circumstances.

107. Shut-off valves, covers, and any other product shut-off devices of the tank truck or train tank wagon have to be closed properly. Only the shut-off valve, the cover and any other

product shut-off device that is necessary to load or unload can be opened.

108. During the connection and disconnection of the loading and/or unloading pipe to the tank

truck, the engine of the tank truck has to be switched off.

109. During the connection and disconnection and during the transfer, the tank truck or train tank

wagon has to be parked in such a manner that driving away during the transfer activities is

prevented.

110. Before loading is begun, the correct distinctive marks have to be put on the tank truck to be

loaded or on the train tank wagon to be loaded.

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7.3.3 Ships (piers)

111. When transfer of a product that constitutes a fire hazard is transferred to a tank in which an

explosive gas mixture can be present and electrostatic loading is possible, the liquid velocity

in the filling pipe has to be limited to 1 m/s during an initial period as referred to in the

report Risks of static electricity in the processing industry in ASTM-D-4865-96 [Ref. 17] and the NFPA [Ref. 78].

112. Piers and quays have to be created with a gradient, and have a raised edge on the side of the

water. There have to be facilities to prevent harmful direct discharges into the surface water.

113. The piers have to be built in such a manner that where tankers are loaded or unloaded, spilt

or leaked products, if any, or rain or rinse water polluted with products cannot flow to a

separator other than through a closed pipe, or can be pumped away or collected for drainage.

114. When quays and piers are cleaned, no spilling losses can end up in the surface water.

115. One cannot begin loading or unloading tankers before an internal, written procedure drawn

up in advance has been followed, containing that the Safety Checklist for ocean-going tankers [Ref. 88], or for inland navigation ships the Checklist ADNR [Ref. 26], has to be filled out completely. The regulations set in same or arising from same have to be included

in this procedure. The competent authority can set further requirements for this procedure.

The above provision does not relate to the necessity of placing insulation between quay and

ship, in as far as it concerns situations in which hose connections are used, provided that

adequate measures have been taken to the satisfaction of the Health and Safety Inspectorate

to prevent the creation of flammable and/or explosive gas/air mixtures.

116. In an internal, written procedure drawn up in advance it has to be included that, to prevent

overflow, spills, and leaks when loading and unloading inland navigation ships, as a

supplement to the valid provisions laid down in the ADNR checklists, agreements between the ships crew and the staff on the quay are laid down in writing, notably in particular with regard to:

a. the maximum pump velocity;

b. the maximum counter-pressure when pumping on the location of the quay/ship

connection;

c. the stop procedure in case of malfunctions;

d. the number and sequence of the switches to other ship tanks and/or land tanks to be

expected.

Furthermore, this procedure has to contain that these agreements are in the hands of the

responsible company officer during the stay of the ship at the pier of the establishment, and

that this procedure has to be retained at the establishment for at least one month. The transfer

has to take place in conformity with this procedure and the agreements.

117. There have to be means available to measure the counter-pressures and to determine the

loading and unloading velocities.

118. The loading and unloading of ships can only take place in accordance with internal, written

procedures drawn up in advance, containing at least the following elements:

- that connecting and disconnecting of loading and unloading arms or hoses takes place

under direct supervision of an officer of the quay installation;

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- that a two-way communication system is maintained during loading and unloading of ships

when television systems are used;

- that the supervision is taken over by the responsible officer of the quay installation if,

when television systems are used, an unclear screen image has been created by whatever

cause;

- that during the transfer by pumping the supervision can only take place by a television

system, after the officer of the quay installation has determined that the loading and

unloading takes place without malfunctions and without risk of release of liquids or gases;

- that the officer of the quay installation takes over the direct supervision during loading or

unloading and takes measures when this is necessary for the safety and/or prevention of

emissions;

- that during loading or unloading, the officer of the establishment and a guard on the ship

constantly see to it that there are no leaks, spills, etc.

The supervision over the quay installation and the ship, as well as the communication

between the ships crew and the quay staff, has to be regulated identically for inland navigation and marine navigation, as referred to in points a5 through a8 of the Safety Checklist for ocean-going tankers [Ref. 26]. The communication system prescribed in point a6 does not have to be applied if the communication is possible without tools, based on the

distance and the circumstances. If the officer of the establishment has determined that the

supervision on board a seagoing ship or the inland navigation ship is not conducted or not

adequately, he promptly has to take measures to restore the communication. He has to stop

the loading or unloading (cause it to be stopped) if the communication cannot be restored or

if there is an irregularity (leaks, spills, etc.).

119. On each pier where inland navigation ships are loaded, facilities have to be present with

which the overfill protection on these ships as prescribed in Annex B of the ADNR can be connected to the overfill alert of the quay installation.

120. In the establishment only inland navigation ships that comply with Annex B of the ADNR

can be loaded.

121. When activating the outlet of the ships tank, as referred to in Annex B of the ADNR, optical and acoustic alerts have to be switched on on the ship, on the pier, and in the control room.

The installations have to be designed in such a manner that on the side of the quay measures

can be taken with them against the overflow of liquid from the ships tank.

122. The overfill alert of the quay installation has to meet the prevailing requirements in

accordance with the German Technische Regeln fr brennbare Flssigkeiten [Ref. 87], or directives to be put on a par with it, and this at the discretion of the competent authority.

123. The use of an overfill protection when loading and unloading ships can only take place in

accordance with internal, written procedures drawn up in advance, containing at least the

following matters:

- that the bridging or switching off of the overfill protection or parts hereof is not permitted,

unless it is necessary for safety;

- that bridging or switching off the overfill protection or parts hereof is indicated and

registered unequivocally in the control room of the quay installation;

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- that during bridging or switching off of the overfill protection or parts hereof the loading

takes place under personal permanent supervision of the responsible officer of the quay

installation;

- that the overfill protections are inspected as to proper functioning before the beginning of

each loading. This inspection includes:

a. the functioning of the electric locking for the coming into operation of the overfill

protection of the quay installation;

b. the presence of the electric binary signal of the outlet of the overfill protection on the

ships tank for the automatic coming into operation of the overfill protection of the quay installation.

7.4 Product pipes and pipe tracks

124. Product pipes are preferably installed aboveground.

125. Pipelines in which poisonous, stench-creating substances, and/or substances constituting a

fire hazard occur, as well as the appurtenances, have to be submitted to a pressure resistance

test before being put into operation, as referred to in the Pressure Equipment Commodities

Act Decree [Ref. 95].

126. There has to be a system from which it can be derived quickly what substance is in the

pipeline and what the direction of the flow is.

127. All sample points have to be provided with a clearly visible and legible sign or name from

which it can be derived for what product the connective point is used. For pipes meant for

different substances, this may be deviated from, provided that one uses a procedure with

which calamities on account of a change of product can be prevented.

128. Flanged joints, flexible joints, and bellows have to occur as little as possible.

129. Pipe trenches for pipelines between individual installations through which poisonous,

stench-creating, and/or flammable substances are transported, have to be subdivided by

means of liquid barriers/fire barriers. The mutual distance between these liquid barriers/fire

barriers has to remain limited to approximately 150 m.

130. Pipelines meant for products of classes 1 and 2 with a conductivity between 0.1 and 50 pico

Siemens per meter that end as an unloading point or end in vessels in which explosive

vapor-air mixtures can be present, have to be designed and manufactured in such a manner

that the electrostatic load present in these products is removed.

131. Pipelines have to be resistant to the load of traffic in case of a duct under a road.

132. Pipes and pipe supports that are located at a road have to be protected by a crash-barrier or

similar construction if a collision can cause a dangerous situation to the surroundings.

133. Underground steel pipelines with appurtenances through which soil-polluting substances are

transported have to be protected against corrosion in accordance with the prevailing

Netherlands standards and practical directives:

- NEN 6901 [Ref. 58];

- NEN 6902 [Ref. 59] and NPR 6903 [Ref. 79];

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- NEN 6910 [Ref. 62] and NEN 6907 [Ref. 61] and NPR 6911 [Ref. 80];

- NEN 6905 [Ref. 60];

- or other similar standards or directives.

134. If soil examination, conducted by an organization designated or accepted by the competent

authority, establishes that:

- the specific electric soil resistance is smaller than 50 ohm.meter (in water extraction areas

100 ohm.meter) or

- the acidity (pH) is lower than 6 or

- the impact of stray currents is greater than what corresponds with the permitted

interference criteria or

- joints occur between dissimilar metals, which can cause galvanic corrosion or

- the environment is anaerobic,

the underground pipelines with appurtenances through which soil-polluting substances are

transported, unless there are objections for other technical reasons, have to be protected

against corrosion on the outside by a cathodic protection in accordance with NEN 6912

[Ref. 63]. Additionally, instead of the limit value of the metal-electrolyte-potential referred

to here, the polarization potential always has to be used. The cathodic protection has to be

inspected and approved by an organization designated or accepted by the competent

authority as to design, manufacture, and proper functioning.

135. New underground pipelines with or without cathodic protection have to be installed at such a

distance from other conductive underground objects that no mutual influencing takes place

that can lead to damage. For this purpose, the following minimum distances apply:

a. between pipes mutually 0.50 m;

b. for foundations, groundings of buildings, and constructions of electrical appliances: 0.70

m;

c. for underground high-voltage pipes: 5 m (nominal tension between the phases > 1,000 V

or between one phase and zero > 600 V).

136. Aboveground insulated joints of cathodically protected underground pipelines or equipment

have to be bridged in places where there may be a risk of explosion by spark-gaps in air-

tight casings in accordance with NEN 3125 [Ref. 53].

7.5 Product shut-off valves

137. All fast shut-off valves in product pipes have to be made fail-safe.

138. It has to be clearly visible on site on shut-off valves in product pipes that have to get into a

fail-safe mode whether they are opened or closed.

139. Shut-off valves in product pipes that are only used in exceptional cases have to be made in

such a manner, if a risk and/or any burden to the environment can arise due to incorrect use,

that direct control during normal operation is not possible.

140. To prevent undesired outflow, shut-off valves in product pipes that discharge into the

outside air and that are used in exceptional cases need to be equipped with blind flanges or

sealing caps.

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141. Shut-off valves and control valves in product pipes, necessary in emergency situations, have

to be operable on location as well as from at least one other location.

142. Fast shut-off valves in product pipes of which it has been established that they are essential

in emergency situations have to be operable electrically or pneumatically and also

manually.

7.6 Utilities

In an establishment steam, inert gas, and compressed air are used for various purposes. In this

directive, the regulations for steam and compressed air are not described. For this purpose,

reference is made to the directives concerned.

Nitrogen can be supplied through a pipeline. This pipeline has to meet what is stated in Chapter

7.4. In addition, it is possible that a reservoir for the storage of liquid nitrogen including the

vaporizer belonging thereto is placed on the installation.

143. The reservoir with vaporizer meant for the storage of liquid nitrogen has to be installed

outside in a well-ventilated place. The reservoir wit